THE COLLEGE OF FAMILY PHYSICIANS

OF CANADA

LE COLLEGE DES MEDECINS DE FAMILLE DU CANADA

WHY FAMILY MEDICINE? Family medicine offers challenges, flexibili ty, and tremendous diversity. Famil y phys icians provide comprehensive care for patients and their families w ithin the community, w ith a focus on prevention, management of chronic disease, and coordination of care. Famil y physicians have the opportun ity to provide care in a variety of settings, including medica l clini cs, emergency departments, acute care settings, and in patients' homes. Some work internationally prov iding care to people in low-resource countries. With many physicians working in teams and w ith other health profess ionals such as nurses, occupational therapists, and nutritioni sts, the field is also becoming more coll aborati ve.

Training for a career in family medicine Famil y phys icians are often the first line of care and care fo r patients w hen they present w ith i llness through the management of chronic diseases. Students shou ld consider family medicine if they: • Are interested in being generalists; famil y phys icians speciali ze in breadth rather than depth of knowledge, amassing an equal but

diffe rent knowledge base to specia lists • Enjoy diagnos ing and managing the undifferentia ted patient: family phys ic ians have the opportun ity to see patients from their f irst

presentation, and to manage their care both independently and in partnership w ith other medica l professionals in the community • Are attracted to a number of di fferent specia lties and want their practi ces to encompass a w ide range of disease presentations • W ant flex ibili ty and control over their schedules • W ant to form long-term relationships w ith their patients

Diversi ty in patients, work setti ngs, and schedu les makes family medic ine the most flex ible career in medici ne. A variety of practice models, the opportuni ty to job share, and the abil ity to shape thei r practi ces offer family physicians a great dea l of choice. The high demand for family physicians in almost every region of Ca nada also opens many opportunit ies fo r locum posi tions and travel.

Some family physic ians also choose to incorporate a focused area into thei r scope of practi ce. Nearl y one-third of family medicine res idents complete additional training to better prepare them for the patients they wi ll encounter w hile serving thei r community's specific needs.

Students may also pursue training through Enhanced Skills (R3) programs, ranging from a few months to one year. In 2008-2009, 196 R3 positions were available in Canada for fami ly medicine res idents. At some schools, prospective students can secure funding to support an R3 training program based on their unique ca reer goa ls; ava ilability and focus va ry by school. Exa mples of Enhanced Ski ll s programs include emergency medicine, sports medic ine, geri atri cs, women's health (obstetri cs, gynecology), adolescent medic ine, mental hea lth, research training, substance abuse treatment, international hea lth, and HIV/AIDS.

Income for family physicians varies w idely depending on hours, location, incenti ves, and type of practi ce. Within a group practice, family phys icians should earn over $175,000 after overh ead and before taxes.

Incentives for practic ing in underserved areas range from higher sa laries and higher fee-for-service payments to loan forgiveness, lump­sum payments, increased continuing medica l educa tion, and holiday support . Most rural phys icians have lower overhead costs and the opportuni ty to earn higher income for performing procedures that would otherwi se be carri ed out by other specialists .

In the midst of Canada-wide and global shortages of fami ly phys icians, the Canadian government is rea lizing that a robust primary care system is vital to the sustainabi li ty of our health care system. Will you be the future of family medicine?

For more information please see http://www.cfpc.ca/whyfamilymedicine

This is a condensed v~rsion of this ~ocument. For the complete pamphlet with more detailed information, please send an email to soms@cfpc.ca to rece1ve a full vers1on electronically.

Authored by: lan Scott MD MSc DO HS CCFP FRCPC FCFP (Vancouver, BC) Goldis Chami BA BSc (Vancouver, BC) Special thanks to all of the medica l students who have contributed their feedback.

This article has been made poss ible through a financial contribution from Health Ca nada . The views expressed herein do not necessa rily represent the views of Health Canada.

The University of Western Ontario Medical Journal Volume 80, Issue 2, Fall 2011

www.uwomj.com ~~~~~----~--------------------------' EDITORIAL

Allin the Head Pencil/a Lang

ARTICLES

Microvascular free flap transfer for reconstruction of oromandibular defects Brennan Ballantyne, Sandeep Dhaliwal

Faculty Reviewer: Dr. Anthony Nichols. MD

Malignant airway obstruction: treating central airway obstruction in the oncologic setting Esther Chan, Niron Argintaru

Faculty Reviewer: Dr. Bela/ Ahmad

listening with our teeth! The SoundBite Hearing Aid : a new technology for single-sided deafness Melissa J. MacPherson, Mayaarendra Ravichandiran

Faculty Reviewer: Dr. Lome Parnes, MD

Falling on deaf ears: overview of cochlear implantation issues in Canada and locally Niran Argintaru, Mosko Hamidi and Laura Allen Faculty Reviewer: Dr. Sumit K Agrawal MD

" Is Beauty Truly in the Eye of the Beholder?"- The Universal Nature of Facial Beauty M ichal Brichacek, Robert Moreland Faculty Reviewer: Dr. DamirMatic, MD MSc FRCSC

Incidence of acute respiratory distress syndrome and acute lung injury in patients requiring prolonged mechanical ventilation Paul Kudlaw, Chu L, Herridge MS, M.D., M.P.H Faculty Reviewer: Nigel Paterson, M.D.

Shortness of breath in a 12 year-old boy: a classic presentation of stage IV Hodgkin's Disease? M ichael Livingston Faculty Reviewer: Dr. Neil Merritt, M.D., FRCSC

Obstructive sleep apnea in children: the when, how and why of screening Kirsten Jewell

Faculty Reviewer: Dr. Murad Husein

An interdisciplinary approach to voice disorders Emma Farley (Meds 2013}, Ashley Kim (Meds 2013} Faculty Reviewer: Or. K. Fung

Transoral Robotic Surgery (TORS) Jason Xu, Michal Brichacek Faculty Reviewer: Dr. Kevin Fung, Dr. Anthony Nichols

The role of FOG-PET and PET /CT in the diagnosis and staging of head and neck cancer Adrian Matthews, Jai Prashanth Jayakar and Joshua Rosenblat

Faculty Reviewer: Dr. John Yoo

Marijuana use: sequelae and implications for health promotion Karline Treurnicht Naylor, Daniel James and Stephanie Gottheil

Faculty Reviewer: Dr. Donald Farquhar

An Interview with Dr. David Leasa Lauren Sham, Abdul Naeem, Joyce TW Cheung

A lung mass and digital clubbing in a young woman Julie Lebert, Joyce TW Cheung Faculty Reviewer: Dr. David Leasa, Dr. S. Nelson

The economics of health and healthcare: a primer for the medical student Hang Shi

Faculty Reviewer: Or. Greg Zaric M.ASc, MS, Ph.D.

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The University of Western Ontario Medical Journal EDITORIAL TEAM

EXECUTIVE TEAM

EDITOR-IN-CHIEF LAURA HINZ (MEDS 2011)

PASQUALE MONTALEONE (MEDS 2011)

SENIOR ASSOCIATE EDITOR PENCILLA LANG (MEDS 2011)

PAUL KUDLOW (MEDS 2013)

JOYCE T.W . CHEUNG (MEDS 2013) JUNIOR ASSOCIATE EDITORS

LAYOUT EDITOR MAYOORENDRA RAVICHANDIRAN (MEDS 2013)

DEPARTMENTAL EDITORS

CLINICAL PROCEDURES SAN DEEP DHALIWAL (MEDS 2013), BRENNAN BALLANTYNE (MEDS 2014)

DIAGNOSTIC REVIEW JAI JAYAKAR (MEDS 2013), ADRIAN MATIHEWS (MEDS 2013), JOSH ROSEN BLAT (MEDS 2014)

ETHICS AND LAW MOSKA HAMIDI (MEDS 2013), LAURA ALLEN (MEDS 2013), NIRAN ARGINTARU (MEDS 2014)

HEALTH PROMOTION PAUL KU DLOW (MEDS 2013), STEPHANIE GOTIHEIL (MEDS 2014)

HISTORY OF MEDICINE PENCILLA LANG (MEDS 2011)

INTERDISCIPLINARY EMMA FARLEY (MEDS 2013), ASHLEY KIM (MEDS 2013)

MEDICINE AND TECHNOLOGY MAYOORENDRA RAVICHANDIRAN (MEDS 2013), MELISSA MACPHERSON (MEDS 2014)

PROFILES JOYCE TW CHEUNG (MEDS 2013), ABDUL NAEEM (MEDS 2014), LAUREN SHAM (MEDS 2014)

THINKING ON YOUR FEET ESTHER CHAN (MEDS 2013), ROMAN SHAPIRO (MEDS 2014)

ZEBRA FILES MICHAL BRICHACEK (MEDS 2013), JULIE LEBERT (MEDS 2013)

HEALTH POLICY AND ECONOMICS PAUL KUDLOW (MEDS 2013), KARLI NE NAYLOR (MEDS 2013), HANG SHI (MEDS 2013)

EDITORIAL BOARD

DR. LOIS CHAMPION DR. FAISAL REHMAN

DR. MICHAEL RIEDER DR. JIM SILCOX

DR. JEFFREY NISKER DR. DOUGLAS QUAN

COVER ART: MICHAL BRICHACEK

FRONT: The left half of the image shows what we as physicians can see. There are few other areas of the body where knowledge of anatomy is as crucial in understanding disease pathology. The airway, ea r, and nose all require an optimal shape to function; the lungs need space to expand . Physiology allows us to understand the integration of structure with function . The right half of the image shows what we cannot see, and rather what we must think. It is essential to look beyond the obvious, considering the underlying anatomy and physiology, in order to understand .

2

Allin the Head

Pencilla Lang (Meds 2011)

I n the middle ages, a common treatment for fo reign bodies in the throat was to ca ll upon St. Bla ise, the "defender of the throat":

"Piece of bone or thorn. whatever thou art, just as Jesus Christ caused Lazarus to come forth from the tomb and Jonah from the belly of the whale (here the patient should be eized by the throat) in the name of St. Blaise, martyr and servant of Christ, 1 order three to come up or go down" - Aetius of Amida (4th century AD)1

Other early remedi es included the use of the dung of lambs, the j uices of a snai l pi erced with a needle, the ashes of burnt wa llow mixed with hay, or cent ipedes mi xed with pigeons' dung applied externa lly. 2

In Grade 5 I wrote a poem in which I described the virtues and drawbacks of each medica l spec ialty. In it, oto laryngology held the double distincti on of being the mo t di ffic ult specialty to pronounce and spe ll. Banished fro m my thoughts fo r these reasons, I gave di eases of the ears, no e and throat little thought until I was capti vated by the complexity and mystery of the sphenoid bone in medica l chool. Over centuries, the study of anatomy and phys io logy have debunked many superstitions. We now know that poisons dropped into the ear do not have the same effect as poisons swa llowed (as was be lieved during Shakespeare's time), and that ting ling in the left ear is not caused by our peers speaking poorl y of us. Equa lly many mysteries remain . What causes allergic rhini tis ra tes to ri se a nd fa ll a m o ng po pul a ti ons? W ha t is th e pathophys io logy of mitochondrial hearing loss? Are minimall y invasive procedures an effective way to remove tumours with less damage to surrounding tissues?

The study of ENT covers a vast spectrum of di seases and crosses many medical spec ialtie , from wimmer's ears and sore throats that frequent primary care offices, to problematic difficult airways in anesthesia, and tumours visualized only through imag ing. Thi s issue of the UWOMJ is an eclecti c mi x of topics. We bring you articles on the SoundBi te hearing aid that a ll ows a person to 'hear' with the ir teeth, free-flap oromandibu lar reconstructi on techniques, a new transoral roboti c surgery procedure, the debate surrounding fund ing o f cochlear implants in Canada, and many more.

Since it 's establi shment in 1930, the UWOMJ has been continua ll y changing and growing to meet the needs of our communi ty. I fi rst got in volved with the VWOMJ as a junior departmental editor in 2007, and over the years I have had the pri vi lege to witness extraordinary growth in thi s journal. Highli ghts have incl uded the forg ing of a partnership with CU Adverti sing all owing the printing and di stributi on of the UWOMJ free of charge to readers, a beautiful new layout, a new online presence at http :// www. uwomj .com/ (please do drop by and visit !), and the creation of feature arti cle, departmenta l and artwork awards to recognize the contributi ons of UWO medical students. The editorial team expects the 2011-201 2 year to bring even more change - keep your eyes peeled for an interacti ve online component to the journal!

Despite the changi ng landscape, the UWOM J remains a publi cation of work written by and for UWO medica l and denta l students. Our objectives are twofold : to educate and enlighten by encouraging the sharing of in fo rmation and idea between student , teachers and our medi ca l community, and to a ll ow UWO medical students to ex perience the process of craft ing their own research, rev iew and case study arti cles. We in vite you to join us this year a an author, supporter or reader.

REFERENCES

I. Ro lleston, J. D. Laryngology and Folk-Lore. The Journal of Laryngology & Otology. 1942;57( 12) : 527-532 .

2. Dani el CL, tevan CM. Encycl op~tdia of uperst itions, Folklore, and the Occult Sciences of the Worl d (Volume I). Detroit: Gale Resea rch Co; 1903 .

UWOMJ I 80 :2 I Fall 2011 3

6ii"JICAL PROCEDUR,ES . _:--:·~· .-. .· .;;:?~ . . _ ... _ -- - . / -

Microvascular free flap transfer for reconstruction of oromandibular defects

Brennan Ballantyne {Meds 2014}, Sandeep Dhal iwal {Meds 2013}

Faculty Reviewer: Dr. Anthony Nichols, Department of Otolaryngology- Head and Neck Surgery, UWO

Reconstruction of the mandible present unique cha ll enges to the head and neck surgeon. A lthough mandibul ar defect can resu lt from trauma, infect ion, congeni ta l deformities, or

osteonecros is, it most commonl y occurs fo ll owing ablative surgery fo r the treatment of benign o r malignant neoplasms. Primary intra­bony mandibular carci noma is rare; there fo re, the involvement of the lower jaw is usua lly secondary to neoplasm ex tension from the o ra l cavity or the o ropharynx. A lthough tumour resecti on to ensure patient survival is a surgeon's primary concern , not to be overlooked are aesthetic and quality of life parameters. The mandible serves to provide shape for the lower third of the face, a border between the face and neck, and po itions the mentum and lower lip. Functionally, it supports masticatory forces and the mandibu lar dentiti on as we ll as the tongue in both pos it ion and function . On average, it must su ta in a force of 726 with a maximal force occurring at the molar teeth of 4346 N. 1

The use of nonvascu larized techniques for repa iring the mandible provides excell ent results in certai n pati ents. For example, allopl asti c implants, such as those composed of titanium , provide rapid recon truction options without the need for ha rvest ing autogenous free fl aps. However, the di sadvantage of this method is the ri sk of pl ate fracture, pl ate extrus ion, and exposure with subseq uent infection . A lternat ive ly, free tissue transfer provides superior re ults in repai ring mandibular defects in most ituati on as an abdundance of literature is available to sugges t that such techniques improve patients' quality of li fe .2·3 Figures 1-4 outline the basic pr incip les of tum o ur resec ti o n a nd oro ma ndibul ar recon !ruction . Currently, there are severa l urgica l option ava ilable for the repai r of oromandibula r defect us ing mi crova cul a r free fl ap methods.

FIBULAR OSTEOCUTANEOUS FREE FLAP

The fibul ar free fl ap has been deemed the " workhorse" donor s ite for reconstruction of oromandibul a r defects because o f it versati lity, frequent use, and success rates that approach upwards of 95%.4-6 The fibu lar fl ap i vascularized by the peronea l artery and its two assoc iated venae comitantes. The entire fibul a (- 25cm) can be harvested except for mall segments at the di ta l and prox imal ends to preserve joint stab ility and ca n be used with the fl exor ha lluc is longus muscle or a sk in paddle for additiona l oft ti ssue repair.7 As such, it is the natura l choice when longer lengths of bone are needed to repa ir a surg ica l resec ti on and an exce ll ent cho ice for reconstructions that require primaril y bone or where the mandibl e is atrophi c.8 The fibu lar fl ap prov ide enough bone fo r supporting dental implantati on and is an idea l match fo r the contour of the natura l j aw anatomy.

Critic isms o f the fibul a r free flap have surrounded the he ight di screpancy compared to the nati ve mandible , and the inability to

reconstruct la rge-sca le so ft ti ssue defects (ie. those resulting from tota l g lo sectomies) . otwi thsta nding, continued innovation has resulted in the development of a "doubl e-barre l" technique that folds the fibu la onto it e lf and the reby effecti vely doubles the height of the mandibl e avai lable for osseo integrated implants.9 Large soft ti ssue defect can be repaired by u ing a second fl ap such a the radial fo rearm free fl ap o r pectora l is myocutaneous flap . 1° Finally donor site morbidi ty is a pa rticu lar concern . Although most patients will experi ence a hindrance in ankle planta r- and dors i-flexion range of moti on and trength te ting, tudies have hown that thi decrease is not enough to impact patients' quality of life. 11

SCAPULAR OSTEOCUTANEOUS FREE FLAP

The capular osteocutaneous free fl ap ( OFF) is a versatile fl ap for mandibula r reconstruction as it enables repair of many bone defects while imultaneou ly providing an abundance of soft tissue for repairing defects that involve fac ia l ski n and o ra l mucosa. The SOFF can provide up to 14 em of capular bone, and is ba ed on the circumflex scapular artery and vei n.12 The branching pattern of the vasculature permits harvesting a number of fasciocutaneous and osteocutaneous flaps . Often, part of the lati s imus dors i and/or erratu ante rio r va cularized by the thoracodorsal a rtery and ve in

can be incorporated to provide more soft ti ssue bulk. Neverthe le , the limited length, wid th and integrity of bone ava ilable makes the scapul ar fl ap unsuitable for denta l implants. Decrea ed range of shoulder moti on can occur if aggress ive post-operati ve physical therapy is not carried out. However, near nonnal function can be obtai ned if proper rehabi litation i pursued. A drawback of the fl ap is the n eed to change the position of the pati ent during surgery from upme to latera l fo r harvesting. Thi s prevents harvest of the flap at

the same time as the tumor ablation, whi ch may prolong the case.

SCAPULAR TIP OSSEOUS FREE FLAP

Preferred by the head and neck team at the University of Western Ontario, one increasing ly popular a lternative to the trad itional scapula r fl ap is the scapu la r tip osseous free fl ap based on the angular branch of the thoracodorsal a rtery. Thi s modified fl ap enable the use of up to 20 em of bone, is often harvested with the lati s imus do rsi and/or . serratu anterio r muscles, and provides the option of 1 ~ crea _mg the kin and musc le pedicle length by a lso extending the dissecti on to the subscapular artery and ve in. Thi s a ll ows the pedic le ~ength to reach upwards of I 7 em compared to 6 em from the OFF. 3

Furthermore, the triangu_lar nature of the infe rior angle o f the scapu la a ll ow for harvestmg a greater vari ety of 3-dimensiona l shapes: . These reco ns tru c tion adva ntages - increased bone ava il abil ity, mcreased pedic le length , and bone geometry _ offered by tl~e scapula r tip free fl ap have been shown to be associated with highly successfu l surgica l outcomes .1 4

4 UWOMJ I 80 :21 Fall 2011

ILIAC CREST OSTEOCUTANEOU FREE FLAP

The iliac crest osteocutaneou free fl ap (I OFF) offers unique advantages ~ver the fibul ar fl ap with re pect to quality and quantity of bone ava ilable. The natura l shape of the ili ac crest resembles the mandibl e anatomicall y, and therefore minimal osteotomy is required to form the neomand1ble. For example, the hemimandible can be recreated from the ip ilateral ilium using the anterior superior ili ac pme to restore the mandibular ang le. 15 The avai lable bone has a

height comparable to the nat ive dentate mandibl e, and is therefore an optunal substrate for denta l implantat ion. However, the surgery is very complex compared to newer options, and has been largely supplanted by the fibular free fl ap as the primary choice. The ICOFF blood. uppl y is based upon deep c ircumflex iliac artery and vein7 The mtem al oblique mu cle is thin and pliable and can be manoeuvred independently of the bone easi ly and reliably.I S A s1gmficant drawback to the u e of the ICOFF is that harve t invol ve the release of the ~bdomina l muscles to access the peritoneal space leadmg to morbidity at the donor site, inc luding issues of hemi a preventiOn a t the abdominal wa ll , ga it a lte ration , se nso ry disturbance , and acute pain . There fore, ignificant rehabilitation is often required to rega in normal ambulation.

RADIAL FOREARM FREE FLAP

The radi al forearm free fl ap (RFFF) has some of the best blood supply compared to other tissue options, is well innervated for good recovery of sensory function , and additional bulk can be added by mcorporatmg the brachioradiali s musc le.7 The arterial supply to the RFFF IS ba ed on the radial artery. There fore, an Allen test must be performed before harvesting thi s flap to ensure the ulnar artery can adequate ly. upply the hand. Venou drainage occurs through the venae com1tantes of the radial artery or via the cephalic vein .

. T~e .RFFF o~ers a large area, thin and pliable skin segment which IS Ideal . for mtra-oral reconstruction thu making it the most ~1de ly u ed microvascular free flap in all head and neck surgery.I 6 It IS used more for defects of the oral cavity, oropharynx, nasopharynx , and tongue as a fasciocutaneous flap , but the option of using it as an osteocutaneous fl ap by including bone is available. I6 Approximately I 0 em of bone can be taken . A lthough it is strong cortica l bone, it tends not to be very thick as on ly 113 of the cro -sectional area of the radial bone can be taken without increasing the ri sk of stress fracture to the arm. As such, RFFF is best suited for latera l or ramus mandibular defects that require minimal amounts of bone but an abundance of so ft tissue. Known limitations include the lack of availab le bone for osteotomy, and morbidity at the donor site due to the bulk of remaining bone. Fracture rate foll owing RFFF approaches 18% of cases, 17 but prophylactic intemal fi xation of the radius has been shown to reduce thi s fracture rate to as low as 4.5%. 18 Tapering edges of graft in a "boat tail" can also reduce the risk of postoperative fractures as can a prolonged period of immobilization (3 weeks).8 For these reasons, on ly small bony defects of the mandible are repaired using radial forearm flap, or it is combined with other donor sites (ie. iliac, fibular or scapu lar). 19

POST-OP I OUTCOMES I COMPLICATIONS

Success rates for free tissue transfer at most high volume centers is high, exceeding 95% or higher.1·10 However, close postoperative monit_oring can detect complications that may affect ti ssue viability, allowmg for early intervention to minimize recipient site morbidity. The most common complications that threaten the viabi lity of the free flap results from vessel thrombosis, predominantly in the veins. 20 Hematomas as a result of the surgery or the failure to place an adequate suction drain are also well-known complications. Other problems that have been cited in the literature as causes of morbidity include pulmonary problems, prolonged ventilatory support, and acute alcohol withdrawaJ.I 9

Postoperati vely, most pat ients are transferred to the intensive care unit fo r an average of 2.44 days, and an average ho pita! stay of 2-4 weeks.21 The most common method of monitoring the graft includes assessment of flap co lour, pin prick and bleeding rate, capi ll ary refill , ski n surface temperature, and Doppler igna l investiga ti ons. Other methods less commonly used are e lectri ca l impedance pl ethysmography, Ia er Doppler, photoplethy mography, tran cutaneous pulse oximetry, and scintigraphy20

. Pat ient are fo ll owed long term to ensure that the flap remain VIable, the aesthetic goals of the patient have been reached, and that the patient is achieving fu nctiona l rehabilitation . A 10 year fo llow up of these patients has revea led that aesthetic outcomes are achi eved in 90% of patients, 70% have regular diets and the remainder have soft di ets, 85% have easily intell igible speech, and greater than 90% have preserved bone height, indicating that there is minimal bone re orption22 These re ults hi ghlight the notion that microvascul ar free fl ap reconstruction has achi eved excell ent outcome th at are ce lebrated by health care teams and their pat ients.

FUTURE DIRECTIONS I CONCLUSION

Head and neck reconstructi ve urgery has seen monumenta l advances in the past few decade . State-of- the-art microva cular equi pment, along w1th the development of numerou free flap ti ssue options ha resulted in vascul arized osseou free fl ap transfer becoming the preferred method for reconstruction leadi ng to a dramatic rise in rep~i: ucce rate.23 Currentl y, in the field of oromandibular repai r, excit.mg new advances are continuall y being made to improve surg ica l outcomes. For example, th e co ncept of di trac tion osteogenesis, originally deve loped for orthopedi c appli cation to l e ~gthen bone, is begi~n~ng to be used by head and neck surgeons. DistractiOn osteogenesis mvolves an extemal mechani ca l device that separates two bony surfaces. The length of the di stract ion is then progressive ly lengthened over everal days to a llow a gap for new bone to form during the consolidation phase. It is used for patients With poor functiOnal outcome following reconstruction due to scar fonnation or inadequate bone length 8 · 12 Moreover, the fi e ld of ti ssue eng ineering also holds promise for the future of head and neck repair. The use of recombmant bone morphogenic protein (rhBMP-2) has been shown to stimulate bone regenerati on without the use o f autologous grafts in an in vitro setting.24 Additional ly, in vivo animal and cadave~ic studies have demonstrated the utility of ti ssue engm~enng m developmg bone grafts for the use of reconstructing mand.Ibular defects.25·26 In thi s manner, the deve lopment of techniques that allow for the transfer of cultured cell substrate to regenerate portions of the mandible w ill likely offer the next step in the evolution of mandibular reconstruction .

REFERENCES

I. Spiegel IH , DeRosa J. Mandibular Recon truction . In : Lalwani AK ed. Current diagnosis & treatment in otolaryngology-head & neck sur~ery. 2nd ed. New York, New York: McGraw-Hill Medical ; 2008:367-373 .

2. Hartl DM , Dauchy S, Escande C, et al. Quality of life after free-flap tongue reconstructi on. The journal of laryngo logy and otology. 2009; 123(5):550-4.

3. Bozec A, Poissonnet G, Chamorey E, et al. Free-flap head and neck recon truction and quali ty of life: a 2-year prospective study. The laryngoscope. 2008; 11 8(5):874-80.

4. Hidalgo DA, Rekow A. A re~iew of 60 consecutive fibula free fl ap mandible reconstructiOns. Plastic and reconstructive surgery. 1995·96(3)· 585-96; discussion 597-602. ' ·

5. Vim K.K, . Wei FC. Fibula osteoseptocutaneous fl ap for mandible reconstructiOn. Microsurgery. 1994; 15(4):245-9.

6 . We1 FC, Seah CS, T.ai YC, Liu J, Tsai M . Fibula osteoseptocutaneous fl ap for reconstruction of composi te mandibular defects. Plastic and reconstructive surgery. 1994;93(2):294-304; discussion 305-6.

7. D1sa JJ , C~rdeiro PG. Mandible recon truction wi th microvascular surgery. Semmars m surgical oncology. 2000; 19(3):226-34.

UWOMJ I 80:21 Fall2011 5

CLINICAL PROCEDURES

8. Mehta RP, Deschler DG. Mandibular reconstruction in 2004: an analysis of different techniques. Current opinion in otolaryngology & head and neck surgery. 2004;12(4):288-93.

9. Chang Y-M, Tsai C-Y, Wei F-C. One-stage, double-barrel fibu la os teoseptocuta neo us fl ap and immediate dental implants for functional and aesthetic reconstruction of segmental mandibular defects. Plastic and reconstructive surgery. 2008;122(1}:143-5.

10.Deleyiannis FW, Gastman B, Russavage j. Microvascular reconstruction of the head and neck. In : Carrau R, Eibling D. Gerguson B, et a l., eds. Operative otolaryngology - head and neck surgery. 2nd ed. Philadelphia, PA: Elsevier Inc.; 2008:739-52 .

11.Anthony jP, Rawnsley jD, Benhaim P, et a l. Donor leg morbidity and function after fibula free flap mandible reconstruction. Plastic and reconstructive surgery. 1995;96(1}:146-52.

12. Miles BA, Go ldste in DP, Gi lbert RW, Gullane Pj . Mandible reconstruction. Current opinion in otolaryngology & head a nd neck surgery. 2010;18(4):317-22 .

13. Hanasono MM. Skoracki Rj. The scapular tip osseous free flap as an alternative for an terior mandibular recons truction. Plastic and recons tructive surgery. 2010;125(4}:164e-166e.

14.Chepeha DB, Khariwala SS, Chanowski EjP, et al. Thoracodorsal artery scapular tip autogenous transp lant: vascularized bone with a long pedicle and flexible soft tissue. Archives of otolaryngology-­head & neck surgery. 2010;136(10}:958-64.

15. Bak M, jacobson AS, Buchbinder D, Urken ML. Contemporary reconstruction of the mandible. Oral oncology. 2010;46(2) :71-6.

16.0lson GT, Bayles SW. Recent innovations in the use of the radial forearm free flap . Current opinion in otolaryngology & head and neck surgery. 2001;9(4).

17.Clark S, Greenwood M, Banks Rj, Parker R. Fracture of the radial donor site after composite free flap harvest: a ten-year review. Surgeon. 2004;2(5):281-6.

18.Avery CME, Danford M, johnson PA. Prophylactic internal fixation of the radial osteocutaneous donor site. British journal of oral and maxillofacial surgery. 2007;45(7):576-578.

19. Rinaldo A, Shaha AR, Wei WI, Si lver CE, Ferlito A. Microvascular free flaps: a major advance in head and neck reconstruction. Acta oto­laryngologica. 2002;122(7) :779-84.

20.Spiegel jH, Polat jK. Microvascular flap reconstruction by oto laryngologists: prevalence, postoperative care, and monitoring techniques. The laryngoscope. 2007; 117(3}:485-90.

21. Ryan MW, Hochman M. Length of stay after free flap reconstruction of the head and neck. The laryngoscope. 2000;110(2) :210-6.

22 . Hidalgo DA. Pusic AL. Free-flap mandibular reconstruction : a 10-year follow-up study. Plastic and reconstr uctive surgery . 2002 ;110(2}:438-49; discussion 450-1.

23. Vaughan ED. Functiona l outcomes of fre e tissue transfer in head and neck cancer reconstruction. Oral oncology. 2009 ;45(4-5) :421 -30.

24. Herford AS, Boyne Pj. Reconstruction of mandibular continuity defects with bone morphogenetic protein -2 (rhBMP-2) . journa l of ora l and maxillofacial surgery. 2008;66(4):616-24.

25. Wilmowsky C vo n, Schwarz S, Kerl jM, et al. Reconstruction of a mandibular defect with a utogenous, autoclaved bone grafts and ti ssue engineering: An in vivo pilot study. journal of biomedical materials research. Part A. 2010;93(4}:1510-8.

26. Eweida AM, Nabawi AS, Marei MK, Khalil MR. Elhammady HA. Mandibular reconstruction using an axia ll y vascularized ti ssue­engineered construct. Annals of surgical innovation and research. 2011;5:2 .

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6 UWOMJ I 80:21 Fall2011

Malignant airway obstruction: treating central airway obstruction in the oncologic setting

Esther Chan (Meds 2013), Niran Argintaru (Meds 2014)

Faculty Reviewer: Dr. Belal Ahmad, Department of Radiation Oncology, UWO

Ob !ruction of the centra l airways, the trachea and main stem bronchi, may result from many disease processes including malignant growth . It is estimated that in the United States,

malignant neoplasms will cause centra l airway obstruction (CAO) in 80,000 cancer patients a year. 1 lt is estimated that 20% of these patients wi ll experi ence ignificant morbidity due to per i tent cough, dyspnea, and obstructive pneumonia, and as many as 35-40% of lung cancer patients die due to complications resulting from loco­regional di sease. 1•2 While most treatments for malignant CAO are not curative, they have been shown to improve resp iratory function , avoid mortality, and improve quality of life.3.4.5•6 Many different strategies for managing malignant airways exist. Choosing the best one depends on pat ient factors such as presence of co-morbidities, medical stability, the nature of the underlying tumour, and overall prognosis. Non-patient related factors such as ex pertise of medical staff and avai labili ty of technology also great ly impact the mode of treatment chosen.2 This article presents current treatment options for malignant CAO, spec ifically, therapeutic bronchoscopy, radiotherapy, and surgical resection .

CAUSES OF MALIGNANT CENTRAL AIRWAY OBSTRUCTION

The most common mali gnant causes of central a irway obstructions are direct extension into the airway lumen by extrinsic tumours (fig. lb).2 Of these tumours the most common types are bronchogeni c carcinomas (i.e. small cell lung cancer and non-small cell lung cancer), fo llowed by esophageal and thyroid carcinomas2 Primary tumours of the trachea and bronchi , or intrinsic central airway tumours (fig. Ia) are re latively rare. Seventy to eighty percent of these tumours are of squamous cell or adenoid cystic carcinoma type. 2 Squamous cell carcinomas typically occur later in life and more frequently in men and smokers, while adenoid cystic carcinomas are found in younger patients and are not related to exposure to smoking or to the sex of the patient3 Occasionally, but less frequent ly, metastases from carcinomas of the breasts, kidneys, co lon, thyroid and esophagus may spread to the respiratory system and cause CAO. 2.7

CLINICAL MANIFESTATIONS AND DIAGNOSIS

Clinical manifestations of malignant CAO depend on size, location , and the rate of progress ion of airway obstruction. Moreover, the patient 's underlying health status and ability to compensate for decreased airflow will influence the extent to which symptoms appear. 1·2 If encroachment into the airway is minor, then there wi ll be little impact on airflow and patients wi ll likely be asymptomatic and never brought to clinical attention . The majority of patients that experience symptoms of CAO have advanced disease and a hi story of underlying malignancy. 7•8 Thus, symptoms of CAO are late findings and include dyspnea, cough, wheezing, stridor and

frequently, pneumonia .1.3·7 Because the e ymptoms overlap with those found in asthma and COPO, patients with malignant CAO are common ly misdiagnosed . However, a trong indi cation that symptoms are due to CAO is that they are unresponsive to inhaled steroids and bronchodialators . Other advanced CAO ymptoms are related to sign of decreased ventilation such as tachycardia, diaphore is and increased work of breathing.7•8 Symptoms of bradycardia, cyanosis and obtundation suggest that the airway lumen is severe ly compromised and in need of immediate interventi on in order to avoid imminent respiratory fa ilure.7

Evaluation and diagnosi s of malignant airways is often based on clini ca l examinations as well as a tissue biopsy and radiological studi es to confirm the diagnosis 2 While chest radiographs have little di agnostic va lue, they may be used to quickly rule out other causes of breathing difficul ty such as tracheal deviations or a pneumothorax.2·3

Che t and neck computed tomography (CT) scans make it possible to estimate tumour size, depth of in vasion, and the ability to see if the airway di stal to obstruction is still patent, providing important infonnati on for treatment planning.2.3 CT scans are typically always performed in conjunction with bronchoscopy, the go ld standard for eva luati ng CAO. Bronchoscopy allows for direct visualization of the tumour, eva luat ion of tumour length and locati on, differentiation between an intrinsic endobronchi al and ex trin ic tumours, and most importantly, is equipped to provide a tissue diagnosis 2 •3 Moreover, if needed, di agno tic bronchoscopy may be quickly converted to therapeutic bronchoscopy for CAO management.

a b

Figure 1: Schematic diagram of 1ntnnsic (a) and extrinsic (b) tumour obstruction of the central a11ways. Each demonstrates 50% occlusion.

Adapted from BeDinger et al. Therapeutic bronchoscopy w fth immediate effect: laser, electrocautery, argon plasma coagulation and stents (2006) .

UWOMJ I 80:2 I Fall 2011 7

TREATMENT MODALITIES

I) Therapeutic bronchoscopy:

Therapeuti c bro nchosco py utili zes the ri g id sta inl ess s tee l bronchoscope to visualize, treat and debulk tumours. Its wider diameter facilitates ventilation allowing for a variety of procedures to be performed, including tumour debulking, laser resecti on, argon­pia ma electrocoagulati on, ba lloon broncho copy, and stent insertion to re-cannuli e the airway2. 7,

i) Tumour debulking:

The harp bevelled tip of the ri g id bronchoscope is u ed to core out the tumour and apply pressure to a irway wa ll s promoting clot fom1ation. However, inadvertent damage to urrounding airways during treatment is a risk and complications may include cutt ing the lips, gum , larynx or a irway muco a or cartilage during intubati on. Perforati on o f the media tinum may also occur if the scope is not in line w ith the airway lumen8

ii) Laser Resection:

Laser energy de li vered by optical fibre is used to resect obstructing tumour . The main type of Ia er u ed during bronchoscopic resection is the eodynium :yttrium aluminum garnet (Nd:YAG) laser which transmit light energy at I ,064 nm wavelength to the ta rget tis ues 2 ,7

The thermal energy from the Nd-YAG laser i absorbed into the core of ti sue where temperature may reach up to 100°C 2 The heat is then tran mitted and cattered around into surrounding tissues o that total ti ssue effects may extend up to I Omm below the surface o f laser admini strati on.2.7·8 Darker pigments, such as those found in blood max imall y absorb energy from Nd-YAG lasers. As a result, ti ssues ex posed to the laser energy are devascul ari zed- a process otherwi se known as e lectrocoagulation7 Additi onal admini strati on of the Nd­YAG Ia er ca u es charring and eventual vapori zati on, which is removed by ventilation from the bronchoscope.2. If tissue is not compl etely vaporized, it may be mechani ca ll y debulked. Beca use tota l ti ssue e ffects are not immediately visible during treatment and may extend well past the depth of the tumour, compli cati ons include late devascularisation of adjacent healthy ti ssues well afte r the treatment i completed.2.s

iii) Argon-Plasma Electrocoagulation:

Argon-Plasma Electrocoagul ati on (A PE), as opposed to laser e lectrocoagulati on, i a form of non-contact e lectrocoagul ati on.

s 111g a 5,000-6,000 vo lt park at the ti p of the probe, argon gas, a lso re lea ed at the ti p, become an ionized plasma that find the nearest grounded tissues produci ng coagul ati ve necros is.1 Advantage of A PC are that it may treat tumours latera l to or around a corner from the tip of the probe that would not otherw i e be access ibl e fo r laser therapy.1·9 T he e lectron energy utilized by A PC, however, doe not penetrate ti sue as deeply as Ia e r energy resulting onl y in uperfi c ia l necros is opposed to the deep ti ue necros i created by

Nd-YAG laser .9 This may be des irable for treating superfi c ia l squamous ce ll carcinomas or if major blood vesse ls are c lose to the tumour bed.9

iv) Balloon Bronchoplasty:

Balloon bronchoplasty u es a ba ll oon to evenl y dil ate the a irway with m1mmal trauma and ub equent granul ati on tissue fonnation in mucosa l ti ssues. :While most ri g id bronchoscope techniques require general anae theti c, ba ll oon bronchoplasty may be perfonned with a fl ex 1bl e bronchoscope under consc ious sedati on.1 Dilation is immedi ately e ffecti ve and may be used for both intrin ic and extrin ic a irway ob truc.ti on . The re ults o f balloon bronchopla ty are ~o t typicall y su sta ~ned and dilation is usually followed by stent111g ?r laser resectiOn . ompli cation include airway rupture result111g 111 pneumothorax , medi astinitis and bl eeding. I

v) Airway stent insertion:

Airway stents are made of s ilicone, metal or a combination of both and are u ed to mechanically prop open obstructed airways. Stents restore airway patency, improve ventilation, and allow for the clearance of airway secretions.2•7·8 They can be used as standalone treatment or in conjunction with debulking and they do not interfere with ubse qu e nt radiation treatments , brachytherapy, or chemotherapy if any are needed.8 Moreover, if the patient's ventilation tatu improve following treatment, silicon stents can be removed.2 However, metal stents are very difficult to extract and are essentially permanent.2· s One of the greatest advantages to using tents is that they may counteract compression by tumours extrinsic

to the a irway. Compli cati on include ste nt migration , more commonly een w ith ili con stents, and stent obstruction by recurrent tumour growth or granulation ti ssue formation (typica lly seen with metal stent ).2.8 ewer metal tents used for malignant airway obstruction have s ilicon covering and are made ofNitinol , a flexible e la ti c biomate ri a l, to help avo id stent obstruction .2 Additionally, newer silicone stent are meshed for fl exibili ty and haped or tudded to prevent tent migrati on2

Indications fo r therapeutic bronchoscopy are the pre ence of ymptoms of advanced CAO. ecrosis, bleeding and cartilaginous

destructi on are not contraindications for treatment. 8 In emergency settings, therapeutic broncho copy may provide more immediate improvement of the pati ent 's ventilator statu and tabili ze them enough for further treatment w ith radi ation or chemotherapy.s Drawbacks to the use of a rigid bronchoscope are that it require pati e nts to be under genera l anaes thetic . Thus, therapeutic bronchoscopy, balloon bronchoplasty withstanding, can only be used in patient that have enough remaining respiratory capacity to tolerate edati on.

2) Radiation Treatment:

Radiati on ha long been used to decrease tumour s ize and improve symptom th~ t result from a la rge tumour burden, espec ia lly in palli all ve settmgs. For malignant CAO, radiation may be delivered in one of two method : intrins ic rad iation treatment ( i.e. brachytherapy) or external bea m radiotherapy (E BRT).

i) Brachytherapy:

Brachytherapy re fer to the placement of a radiation ource within or adj acent to the ~i ue . be ing treated . Thi s is achieved by plac ing ~adJat1on eeds d Jre.ctly mto the tumour ( interstitia l brachytherapy) or 111 e~ling catheter 1nto the lumen of the organ be ing treated such a ~n a1rway. For the treatment of malignant CAO, an empty catheter is 1n erted 111to lumen o f the airway approx imately two centimetre beyond the e timated di ta l end o f a target area that includes the tumour.2 The catheter is then secured at the nostril and a radiation

2 ~urce, most commonly iridiu~11 -l 92 , is then loaded into the catheter. · The area ta rgeted by ~ad1a tJ on can be several centimetre long

depending on whether h1gh-do e radiation (HDR) or low-do e radiati.on (LOR) is u ed .2 However, LOR has fallen out of favour and HDR IS mo t c mmonly. used as it utilizes the greatest advantage of the brac.hytherapy tec.hn1que, ~h~t 1. , the radiation delivered directly at the 1te o f ta rget t1 . sues minimi zes radiation expo ure to nearby hea lthy organ otherw1 e ex posed during external beam radiotherapy. In th1 s way HDR brachytherapy exposes vital tructure near the airway- such a the esophagus, thyroid, mediastinum and aorta- to 11111111nal ~mounts of radiation while enabling larger radiation do es to be deli vered to the target ti s ue ites A typ '1cal HDR · d 1· . · reg1men

e Ivers a fraction dose of 7,000-8,000 cGy admini stered once a wee~ for three. week ; however, the exact dose and number of fractJ.ons (rad~at1on treatment ) will depend on the ize of the tumour and 1~s locat1on .2·8 Each fraction lasts between 3 to 30 minutes a llowmg brachytherapy to be delivered a

8 UWOMJ I 80:2 I Fall 2011

an outpati ent procedure. Brachytherapy is contraindicated for tumours that invade major arteries or other tructures within the medi astinum8 Compli cations include early and late radiation effects uch a radi at ion bronchitis, hemoptysis, bronchial stenosis, and

bronchia l fistu las8

ii) External beam radiotherapy:

External beam radiotherapy (EBRT) has variable efficacy for treating CAO and the therapeutic effects may be quite delayed. However, EBRT continues to be a mainstay of treatment for CAO especia ll y in patients wi th hi ghl y advanced di sease or comorbiditi e that preclude them from undergoing general anaesthetic. Palliati ve doses of EBRT for the treatment of CAO are typica lly 3,000 cGy in I 0 consecuti ve fractions . Side-effects a lso include early and late radiation effects. Early effect are radiation dermatiti s to the overl ying skin and fatigue . Long-tenn effects mainly invo lve thoracic structures close to the airway ( uch as the lungs), whi ch may undergo fibrosis as a result of inadvertent radi ation exposure. However, current techniques in EBRT such as intensity-modulated radiation therapy in conj unction with shielding or stereotactic body radi otherapy effectively minimize radi ation exposure to surrounding ti ssue .

3) Surgical resection:

Surgical resection is usually reserved for tracheal tumours that have not yet metastasized to other areas of the body. If surgica l resection is successful at removing the entire tumour and achieving negati ve margins, it may be a curative treatment for cancer. The procedure involves removal of the tumour and the in volved trachea l segment followed by re-anastomosis or reconstruction of the trachea l tube.3

Tumours that involve the carina or subglottic larynx can be successfully resected while preserving ventilation and voca l functioning .3 In addition, it is possible to remove up to 50% of the cervical or intrathoracic tracheal length without compromising anastomotic hea ling.2.3 While its advantage is that it is a potentially curative treatment fo r cancer, surgica l resecti on cann ot be performed if complete tumour removal threatens the hea ling of the anastomosis, if the tumour length exceeds 50% of the trachea or if vi tal structures such as the aorta or heart are involved.3 Moreover, the presence of CAO symptoms that alert clinicians to the need for treatment typica ll y appear at advanced stages of di sease when metastati c spread has likely to have already occurred . Although surgical resection cannot be performed after the mediastinum has received a hi gh-do e of radiat ion (due to impaired ti ssue healing), it may be followed by adjuvant radiation therapy to decrease the likelihood of loco-regional disease reoccurrence.

DISCUSSION

Interventions for mali gnant CAO are highl y technical and require a large amount of medi cal resources and teams of well-tra ined medical personneJ.2 Often the widespread avail ability of these treatments is limited to patients within a reasonable di stance of specialized center . However, many studi es have shown that these treatments are effecti ve, improve patient quality of life, and may be life-saving in emergent situations.3.4·5·6 In a prospecti ve cohort study of 20 patients with symptomatic CAO, a ll pati ent demonstrated improvements in airway diameter and 16 patients achieved greater than 80% patency using therapeutic bronchoscope techniques4 Moreover, the study demonstrated that Nd:YAG laser therapy alone, airway stenting alone, and a combination of stenting, laser, and/or cryotherapy were each indi vidually effecti ve at re­establishing airway patency and improving symptoms.4 Similar positive results were demonstrated for the treatment of CAO using stent insertion and radiotherapy. Authors of a multi center tri al found that silicone mesh, studded stents re-established patency, and improved fun cti onal capacity, dyspnea, and g lobal functioning at I month and 3 months after stent placement. 5 HDR brachytherapy

has also been fou nd to be successfu l in prospective cohort studi e at improvi ng symptom of CAO by more than 90%6 Lastly, for patients e lig ible fo r surgical resection, surgery offers a high rate of curative uccessJ Whil e most of these tri al compared intervention to no treatment and were not randomi zed control trials, they have demonstrated that interventi on may improve symptom and quali ty of li fe . However, to date there are no best practi ce guidelines avai lable on which interventi ons should be used. It has been frequentl y observed that the best approach includes a combinati on of treatment interventi ons2, and a lthough many centers are already uti li zing these interventions to manage malignant CAO, choice of treatment is heterogeneous and centre-speci fi c.

As incidences of cancer and specifical ly bronchogeni c tumour continue to ri se, it can onl y be expected that a growi ng number of patients wi ll need to be managed for mali gnant CAO. Sign and symptoms of malignant CAO occur at advanced stages of disease and patients suffering from CAO almost a lways have a positive hi story for underlying ma li gnancy. Symptoms of CAO may be treated with a number of techniques including therapeuti c bronchoscopy, radi otherapy, or surgical resection . Each modality has been shown to improve symptomology, decrease morbidity, and improve quali ty of life. There are currentl y no best practice guidelines for managing ma li gnant CAO. While patient fac tors will contribute to the dec ision mak ing process, the cho ice of interventi on may be most determined by centre resources and ava ilabili ty of skilled personnel.

REFERENCES

I. Chen K, Varon J, Wenker OC. Malignant airway obstruction: Recognition and management . J Emerg Med. I 998; I 6( I ) :83 -92 .

2. Ernst A, Fe ller-Kopman D, Becker HD, Mehta AC. Central airway obstruction. Am J Respir Crit Care Med. 2004; I 69( 12): I 278- I 297.

3. Honings J, Ga issert HA , Van Der Heijden H, Verhagen AD, Kaanders J, Ma rres H. C lini ca l aspec ts and treatment of prima ry trachea l malignancies. Acta Oto-Laryngologica. 20 I 0; I 30(7):763-772 .

4 . Amjadi K, Voduc N, Cruysberghs Y, Lemmens R, Fergusson DA , Doucette S, Noppen M. Impact of in terventional bronchoscopy on quality of life in malignant airway obstruction . Respiration. 2008 ;76(4):42 I -428.

5. Bolliger CT, Bre itenbuecher A, Brutsche M, Heitz M, Stanzel F. Use of sh1dded Polyflex stents in pati ents wi th neoplasti c obstructions of the central airways. Respiration. 2004 ;7 I ( I );83 -87 .

6. Muto P, Ravo V, Pane lli G , Liguori G, Fra io li G. High-dose rate brachytherapy fo r bronchia l cancer: Treatment optimization using three schemes of therapy. O ncologi t. 2005 ;5(3) :209-2 14 .

7. Kemstien KH , Reckamp KL. Lung cancer: a multidisc iplinary approach to diagnosis and management. New York: Demos Medical Publishing; c20 I I. Chapter I 9, Tracheobraonchial Cancers : d:YAG laser resection , brachytherapy, and photodynamic ab lati on ; p. 235-242 .

8. Yeung CJ, Esca lante C P. Holl and-Frei oncologic emergencies. Hamilton: BC Decker In c. ; c2002 . C hapter I 0 , o n infec ti ous pu lm onary emergencies; p. I 9 I -248.

9. Boll iger CT, utedja TG , Strausz J, Freitag L. Therapeutic bronchoscopy wi th immediate effect: laser, electrocautery, argon plasma coagulat ion and stents. Eur Respir J. 2006;27 : 1258- 127 1.

UWOMJ I 80:2 I Fall 2011 9

Listening with our teeth! The SoundBite Hearing Aid: a new technology for single-sided deafness

Melissa J. MacPherson (Meds 2014), Mayoorendra Ravichandiran (Meds 2013)

Faculty Reviewer : Dr. Lorne Parnes, MD (Department of Otolaryngology)

Hearing loss is a significant and common disabili ty that affects approx imately 9% of the Canadian population.' Thi s di sabili ty is more preva lent in older populations2 and if

uncorrected can lead to soc ial iso lati on and communi cation difficulties2 ·3 There are two distinct types of hearing loss; each with a characteri stic pathophy io logy. Sensorineural hearing lo (SNHL) arises fro m conditions affecting the inner ear or the cochlear nerve, whereas conducti ve hearing lo s develops from conditi ons a ffecting the outer ear, the middle ear and the tympanic membrane. These di tincti ons are important since hearing aid technologies address the diffe rent types of hearing loss using different strategies . Patients with a conducti ve hearing los require the amplification of all sound wave frequencies. 2•3 In contrast, pati ents affected by sensorineural hearing loss present a much more complicated technological problem since these patients may have decreased audibility of certain sound frequencies as oppo ed to an overall decrease in the audibili ty of all sound frequencies 2 Most pati ents with sensorineural hearing loss have decreased audibility of hi gh frequencies;2 however, in the case o f Meniere 's di sease there is a decreased audibili ty of low frequencies.4 This results in the ability to hear sound but the inabili ty to understand speech since speech amplitude (loudness) is caused by low frequency sound waves which the patient can detect but speech comprehension is poor due to the loss in detection of the high frequency sound wave components.2 Speech comprehension is more diffi cult in the presence of background noi e and consequently hearing aid technologies address thi s issue by increas ing the signal­to-noise rati o to bring out speech from no ise.2

HEARING AID TECHNOLOG I ES FOR UN I LATERAL SENSORINEURAL HEARING LOSS

Patients with unilateral sensorineural hea ring loss ( ingle-s ided deafness) also face difficulti es loca liz ing the direction o f unseen sounds and detecting sound loca li zing from the directi on of the affected ear, in addition to the difficulti es previously mentioned.s The head shadow effect cause a parti cular difficulty for these patients since sound waves orig inating fro m the affected ide are attenuated by the head before reaching the functional ea r. Several technologica l strategies used to address some of these problems include the routing of sound from the di sabled ear to the full y fun cti onal ear using air conduction contralateral routing of sound (C ROS) dev ices or bone-anchored hearing aids (BAHA).2.5

While CROS devices do not allow for sound loca lizati on, they do aid a pati ent to overcome the head shadow effect. CRO devices consist of essenti ally two hearing aids. One hearing aid ac ts as a microphone in the affected ear and transmits the auditory ignal to a second hearing aid that acts as a receiver in the fun cti ona l ear. The CROS hearing aid in current use are wire less devices that u e FM or Bluetooth technology to transmit the auditory signal to the external rece iver.2

BAHA devices take advantage of the physical property of bone to conduct ound . The first BAHA device was developed by a Swedi sh anatomist, Per-lngvar Branemark, and implanted in three pati ents in 1977. The dev ice has achieved international recognition as a solut ion to conducti ve hearing loss with more than 80 000 device currently in use worldwide6 The device also has a second application fo r the treatment of unilatera l sensorineura l hearing loss.5 The BAHA system consists of three components: a titanium post implant, an external abutment and an e lectronic sound processor. It is important to note that the BAHA ystem requires surgical implantation of the titanium post fo ll owed by the integration of the implant into the bony architecture. The device works by transmitting sound through bone to the inner ear thus, skipping both the external auditory canal and the middle ear.2·5 In the case of unil ateral sensorineural hearing loss the sound is transmitted transcranially and stimulates the cochlear fluid of the unaffected inner ear. The titanium screw is implanted directly into the masto id bone in order to overcome the lo s o f energy during the transcutaneous transmission of sound . The electronic sound processor is responsible for the transmi sion of ound vibrations via the externa l abutment to the titanium implant.7 Despite its value and populari ty, there are a number o f complications a sociated with the BAHA device. The most common complication is skin irritation at the site of the implant. 7•8 In most ca e , thi s can be managed using topical therapy. A more serious complication is the failure of the titanium post to osseointegrate.7•8 Thi complication can lead to poor function or failure of the implant. In addition, several less common but potentiall y dangerous compli cati ons such as kin flap necrosis, wound dehi scence, bleeding and pain have been reported8 The sound conducti on property of bone explo ited in the BAHA technology has also been applied in the most recent technological advancement for the treatment o f unilatera l sensorineural hearing lo ; the SoundBite Hearing Aid .

THE SOUNDBITE HEARING AID

A unique technologica l approach for the treatment of unilateral sen orineural hearing loss is the use of a removable ora l device called the SoundBite hearing system developed by Sonitus Medica l. The SoundBite hearing system also makes u e of the ound conduction properti es o f bone; yet, unlike the BAHA system does not require the use of surgery.3•9 The SoundBite hearing system uses a mi crophone unit housing a receiver and wire less transmitter to receive sound . The mi crophone portion of the unit its in the affected ear canal to take advantage of the ability of the ear 's pinna and ext~rnal ear canal to capture and direct sound into the microphone, whil e the rece1ver and the transmitter sit in a unit behind the affected ear3

•9 The unit then transmits the captured ound wirelessly to a

10 UWOMJ I 80 :2 I Fall 2011

removable oral device similar to a retainer that sits over the max illary molars in the mouth. The oral device touches several structures in the mouth including the gi ng iva, teeth and the inner cheek. The electrical signal from the behind the ear transmitter i captured by the ora l device and is transduced into vibrational energy usi ng a piezoelectric transducer.9 The vibration are conducted by way of the teeth to the bone and transcrani a lly to the cochlea of the ear. One of the advantage of the piezoe lectri c transd ucer is that it allows a much wider frequency range to be conducted through the teeth than the traditional e lectrodynami c transducers used in the BAHA systems.9

The oral dev ice does not require the mod ifi cati on of the max illary molars and i custom fitted for each pati ent by taki ng a dental imprint of the max illary arch.3 Si nce the device vibrate the max illary molars to transmit v ibrat ions to the bone, the force of the ora l dev ice wa te ted to detem1ine if it wea rs the teeth . Interesting ly, the force of the oral dev ice is four orders of magnitude lower than the force exerted on the teeth by nonna l masti cation and is within the force range of nom1al orthodontic devices and does not damage the surface of the max ill ary molars.9 Moreover, the ora l device is comfortable, well to lerated in most pat ients, does not affect the speech and can even be worn whi le eating.3·9 There are several advantages of the SoundBite hearing system which are outlined in Box l . The most striking advantage of the SoundBite hearing sy tem when compared to bone anchored hearing aid (BAHA) i the avoidance of surgery9 A patient can be fitted qui ckly for the oral device and begin using the hearing aid immediately. With BAHA, surgery is required to imp lant a titanium post. The surgery is followed by 3 months of healing to ensure osseointegration of the implant before the pati ent can begin to use the device 2 The SoundBite hearing system avoids this delay and avoids potenti al surgical complications seen with the BAHA procedure. The SoundBite hear ing y tem is a tru ly unique and nove l technologica l approach to address unilateral sensorineural hearing loss. The next time you ee a patient with unil ateral sensorineural hearing loss, take a look in their mouth and chew on thi s possibility; they mi ght be li stening through their teeth!

REFERENCES I . Woodcock K, Pole JD. Heal th profile of deaf Canadians: ana lys is of the

Canada Commun ity Health Survey. Can Fam Physician 2007 ;53( 12) : 2 140- 1.

2. Kim HH , Barrs OM . Hea ring a id s : a rev iew of what's new. Otolaryngology-Head and Neck Surgery 2006; 134: I 043-50.

3. Miller RJ . It's time we listened to our teeth : The SoundBite hearing system. America! Journal of Orthodontics and Dentofacial Orthopedics 20 I 0; 138(5):666-9.

4. Sajj adi H, Papare ll a MM. Meniere's di sease. Lancet 2008 Aug 2;372(9636):406-14.

5. Bishop CE, Eby TL. The current status of audiologic rehabi litation for profo und unil atera l sensorineura l hearing loss. The Laryngoscope 2009; 120:552-6.

6. Mudry A, Tjellstrom A. Hi stori cal background of bone conduction hearing devices and bone conducti on hearing a ids. Adv Otorhinolaryngol 20 11 ;7 1:1-9.

7. Kraai T, Brown C, Neeff M, Fisher K. Complications of bone-anchored hearing aids in pediatri c patients. lnt J Pediatr Otorhinolaryngol 20 II Apr

8. Wazen JJ , Young DL, Farrugia MC, Chandrasekhar SS, Ghossaini SN, Borik J, Soneru C, Spitzer JB. Successes and complications of the Baha system. Otol Neurotol 2008 Dec;29(8): 1115-9.

9. Pope lka GR, Derebery J, Blevins N H, Murray M, Moore BC, Sweetow RW, Wu B, Katsis M. Preliminary evaluation of a novel bone-conduction device for single-s ided deafness. Otology & Neurotology 20 I 0;3 1 (3): 492-7.

Box 1: Advantages and Disadvantages of the Sound Bite Hearing System

Advantages Avoidance of surgery and su rg ica l

complications

No need to wait 3 months befo re use since

osseointegration is not required

Discreet oral device and discreet behind the ear

unit

Optimized microphone location

Del ivers high-fidelity sound w ith a w ide

f requency range

Removable devices

Disadvantages Cannot drink alcohol wh ile wearing the oral

device

Risk of aspiration of the ora l device if the

patient's physical responses are impaired

Risk of swallowing the oral device if the

patient's physical responses are impa ired

Healthy teeth are needed to f it the device

properly and good oral anatomy for full benefit;

the last 3 teeth in the maxillary arch are usually

the abutment teeth and must be free of active

caries, periodontal and endodontic conditions

References (3 ,9)

UWOMJ I 80 :21 Fall2011 11

Falling on deaf ears: overview of cochlear implantation issues in Canada and locally

Niran Argintaru (Med icine 2014), Moska Hamidi (Medic ine 2013) and Laura Allen (Medicine 2013)

Faculty Reviewer: Dr. Sumit K Agrawal MD

I s de. afness a disease? Is it even a disability? Can or should it be "cured"?

Such questions have been the root of many debates over the nature of deaf culture since the advent of cochlear implantati on in the late 1950s. As implants become more re liab le and provide increasing quality of hearing to profound ly deaf children and adults, many in the deaf community have grown to view implantation as a threat to both their way of life and the integrity of the communi ty. As a result, factions of deaf society have waged a war aga inst cochlear implants. " I would be remiss not to equate cochlear implants with genocide" stated a 1992 deaf position artic le.1

While such quotations represent an extrem i t view in the communi ty, widespread concerns that cochlear imp lantation would diminish the deaf communi ty 's size and cohesiveness, and that cochlear implantati on represents a desire by the hearing population to "cure" deafness exi ted well into the 1990 .2 Many in the deaf community fear that cochl ear implants would result in decreased resource ava il ab il ty and accommodations for the deaf, and hence pose a threat to deaf culture.

For the purpose of this artic le, deaf culture can be characterized as a communi ty largely composed of pro fo undly deaf indi viduals that views deafness as a difference rather than a disability2 They characteri ze lack of hearing as "deafhood" rather than "deafness", with some in the communi ty going as far as ca lling deafness a " birthright of si lence".3 This comm unity provides resources, ed ucation and training to its deaf members, a llowing them to function within the deaf community (i.e. through sign language) and in the hearing world (i.e . through lip read ing). If one were to consider implantation to be a treatment for profound deafness, most of those impl anted at a yo ung age are likely to not partake in the deaf communi ty as they would now be integrated into mainstream educati on.4

As ev idence mounts in favour of cochlear implantat ion, a shift has been seen to a po int where th e vast majority o r e ligib le chi ldren are implanted, parti cularly if born to hearing parents. In response to the growing prevalence of implantati on, in 2007, the Canadi an Association of the Deaf (CAD) released a posit ion paper on cochlear implantation . They asserted that whi le the CA D has litt le concern about autonomous adult imp lantation, they do not believe emp iri ca l research has provided suffi c ient evidence for the effi cacy of cochlear implants in supporting first-language acqui s iti on in deaf chi ldren, who are unable to make the choice for themse lves.5 As the body of scientific literature in the field overwhelmingly supports early chi ldh ood imp lantat ion, the CAD 's pos iti on appears to focus on the right of every deaf child to learn sign language, regard less of whether they received an implant, a llowing them to grow up " bil ingual and bicultura l". It is diffi cult however to assert whether thi s po iti on

refl ects an effort by the CAD to mitigate the loss of deaf cu lture by trying to increase the involvement of implanted children in the deaf communi ty.

THE RI GHT TO CHOOSE: WHEN TO IMPLANT?

With newborn hearing screening program offered in eight provinces and three territo ri es as of 2008 , children with s ignificant hearing deficiencies are identifi ed earlier than ever6 Therefore, armed with an early diagnosis , parents are dri ven to make a decision regarding cochlear implantation in e ligible children earlier in the child 's life, with an increasing body of evidence indicating s ignificant advantages to earl y implantation . otably, implantation in children under two year o ld has been extensive ly shown to provide s ignificant improvement in language perception and vocabul ary, often allowing recipients to enter first grade wi th language ski ll s comparable to children with normal hearing.7.8 Recent evidence indi cating that implantat ion as early as ix month old lead to better long-term improvements in language, socia l ski ll development and s ignificant advantages in parent-child bonding, has resulted in some centres implanting infa nts even earlier.9 While the current guidelines advise imp lantat ion at around two years old, studi es have shown little additiona l ri sk of implanting patients at a significantly younger age, hence further shi ft ing the trend towards earli er implantation.

Is thi s trend towards early imp lantati on signifi cant in tenns of informed con ent? The main decision to implant has shifted away fro m the patient when early chi ldhood implantation tarted becoming common. This has left parents w ith the full responsibil ity of choosing implantation as well as the degree of deaf education the child will receive if implanted . However, with children implanted earl ier, parents are faced with shorter timelines during which to educate themse lves about the procedure. Therefore, while implanting at six months versus two years does not s ignificant ly a lte r the child 's abi li ty to contribute to the decision, it may decrease the amount of time the parents have to con ider the choice and could arguably pre ure parents into rash decisions.

FUNDI NG OF COC HLEAR IMPLANTS lN ADULTS AND PEDIATRIC POPULATIONS

Current ly, three .centers (Toronto, London and Ottawa) provide the over 190 cochlear implant surgeries performed annua lly in Ontario. With wait times for imp lantation surgery fa r above the recommended three months for pediatric popu lation and six months for adults 10 the Ontario government re leased an additiona l $5.9 mi ll ion i i~ fun?ing in .March ~0 11 to cut wait times in ha lf. 11 Unfortunate ly, it is unlike ly thi s one-time fu nding package w ill address wai tl ist is ues in the long-run, particul arly in the time-sensitive implantation of chi ldren as discussed above.

Specifica lly in London, a s ingle annual budget is provided for

12 UWOMJ I 80 :21 Fall2011

both pediatric and adult implantations. There are several problems that arise from this funding mode l. Firstl y, as implant costs are covered under provinc ial hea lth funding, patients cannot purchase their own implants in accordance with the Canada Health Act. Secondly, since a lump sum is all ocated to the fundin g of implants per hospita l, implantati on can be undertaken only until the sum is ex hausted in a g iven fi sca l year. La tl y, due to the ev idence presented above for ea rly pediatric implantation, in fants must be implanted with in a certai n window of time after the di agnos is. Therefore, as more pediatric implants are perfo rmed, adult patient are pushed back on the wai t-li st fo r their implants. However, this funding mode l does empower the hea lthcare prov ider in the audi ology tea m to eva luate patients and ass ign the funding to those they determine require it most.

UNILATERAL VS BILATERAL IMPLATATION

The Canadian Association of Speech-Language Pathologi ts and Aud iologist (CASLPA) publi shed their official posi tion in the Journal of Otolaryngo logy supporting bilateral cochl ear implantati on in all e li gib le children. Bilateral implantat ions prov ide advantages in sound loca liza ti on, speech isolat ion in no isy conditions and improved deve lopment of the auditory system with few additional ri sks. Additi ona lly, by implanting both ears, the " better ear" (the ear that w ill fu ncti on better with the implant) is always impl anted , maximi zing benefits fo r the pati ent. 12 Hence, fo r the most part, e ligible Canadi an children who rece ive implantation undergo simultaneous bi lateral implantation as studies have shown no advantage to implanti ng the second ear on a later date, particul arly at an older age.13

While pedi atric implantati on has been shown to be cost effecti ve by several tudies 14, the cost effecti veness of providing bilatera l implantation has been questioned due to the use of publi c fundin g of the implants. A systemic review done in the United Kingdom comprised of 33 trials, including two randomized control tr ials showed a fa r higher cost effective quali ty-adj usted li fe-year returns fo r unilateral implantation versus the bilateral implantation in pediatric and adult populati ons. 15 With mounting evidence and strong recommendat ions in favour of bilatera l implantation, why is the cost effecti veness of the second implant much lower than that of the first? Firstly, the quali ty of li fe measures used to gauge improvements fo llowing the second implant are much more uncerta in and inaccurate, as Bond 's 2009 rev iew acknowledgesl 5 For example, it is difficult to measure the improvement in quality of li fe ga ined fro m increased abi li ty to loca lize sound or isolate speech. Secondly, with the abili ty of a unilateral implant to allow children to attend mainstream school and often requ iring almost no specifi c educational assistance, the majori ty of savings are rea li zed with the first implant and are hence not refl ected in the additi on of a second implant. Most significantly, the incremental improvement from having nearl y no hearing to considerable hearing achi eved with a unilatera l implant is bound to be considerably higher than the improvement achieved with the second implant.

CONCLUSIONS

By many accounts, those who argue that cochl ear implantati on is unethical , ineffecti ve or simpl y not the best choice for profoundl y deaf children appear to have been unsuccessful in preventing their widespread use. However, as implantation shifts fro m being a novelty to the norm, the issues of fundin g and cost efficiency appear to have taken centre stage in Canada, and particul arl y in Ontario. With early bilateral implantation established as the best therapy for profoundl y deaf children, funding must be available to implant a ll eligible children whose parents choose implantation. If such funding is not available, as seen in some centres, wait lists will persist and grow particularly in adults as pediatric pati ents are g iven priori ty.

Desp ite the effectiveness of imp lants, it is important not to di count the services and supports the deaf commu nity provides to its members. Imp lantat ion i not a cure; rather, it i a upport ive treatment tha t along with considerable training allows for increased fu nct ioning. Therefore, those implanted may sti ll find they can benefit fro m partici pat ion in the deaf co mmuni ty through support and sign language trai ning.

REFERENCES

I. Si lver, A. Cochlear Implant : Surefire prescription for long-term disease. TBC News. 1992 ;53:4-5 .

2. Balkany, T., Hodges, A. V. , & Goodman, K. W. Ethics of Cochlear Imp lan tat ion in Young Chi ldren. Otolaryngology Head and eck Surgery. 1996; 11 4(7):748-55.

3. Ladd, P. Understandi ng Deaf Cul ture: In search of Dea fh ood. Bristol: Mul ti lingual Matters; 2003.

4. Aronson, J. (Director). Sound and Fury [Motion Picture] ;2000. 5. The Canadian Association of the Deaf. Cochlear Implants [Internet] ; 2007

May 26 [Cited 20 11 March 23]. Avai lable from: http://www.cad .ca/ each lear _ implants%20.php.

6. Adams, J. National ewbom Screening and Genetics Resource Center. Retrieved from Canadian Organization fo r Rare disorders; 2008 July 9. Ava ilab le from http://genes-rus. uthscsa.edu/CA_nbsdisorder .pdf.

7. Kra l, A., & O'Donoghue, G. M. Profo und Deafness in Childhood . New England Journal of Medici ne. 20 I 0;363( 15) : 1438-50.

8. Jvirsky, M. A. , Teoh, S. W. , & Neuburger, H. Development of Langugage and Speech Perception in Congenitally Deaf Children as a Function of Age at Coch lear Implantation . Audiology and neurooto laryngology. 2004 ;9( 4 ):224-33 .

9. Cosetti, M. , & Roland, T. J. Cochlear Implan tation in the Very Young Chi ld : Issues Un ique to the Under- ! Population. Trends in Ampl ification. 2010; 14( 1):46-57.

I 0. Canad ian Assoc iation of Speech-Language Patho logists and Audio logists: Recommended Wait Times [Internet]. Speach and Heari ng; 20 II [Cited 20 II March 23 ]. Avai lab le from: http -ljwww speechandheari ng ca/en/ find-a-professional /wait-time-recommendations?start=l 0

I I . Morrison, A. New room Ontario: Improving Access To Devices For People With Severe Hearing Loss [Internet]. [Cited 20 II March 15] Avai lab le from : http://news.ontario .ca/mohl tc/en/20 11 /03/ improving­access-to-dev ices-fo r-people-wi th-severe-hearing -loss.htm I

12. Schramm, D. Canadian Po ition Statement on Bi latera l Cochlear Im plantati on. Journa l of Oto laryngology Head & Neck Surgery. 20 I 0;39(5):4 79-85 .

13. Graham J, V. D. Bilatera l sequentia l cochlear implantation in the congenita lly deaf child : evidence to support the concept of a 'critica l age' after which the second ear is less likely to provide an adequate level of peech perception on its own. Cochlear Implants Int. 2009; I 0(3): 11 9-4 1.

14. O'Nei ll , C. , O' Donoghue, G. M., Archbold, S. M., & armand, C. (2000). A Cost-Utili ty Ana lysis of Pediatric Cochlear Implantation . T he Laryngoscope. 2000; II 0( I): 156-60.

15. Bond M, M. S. The effecti venes and cost-effecti veness of cochlear implants fo r severe to profound deafness in children and ad ul ts: a systematic review and economic model. Health Techno! Assess. 2009 Sep; 13( 44): 1-330.

UWOMJ I 80 :21 Fall2011 13

"Is Beauty Truly in the Eye of the Beholder?" The Universal Nature of Facial Beauty

Michal Brichacek (Meds 2013), Robert Moreland (Meds 2013)

Faculty Reviewer: Dr. DamirMatic, MD MSc FRCSC, Plastic Surgery

0 ur face allows us to convey our every thought and feeling with those around us in a nearly instantaneous manner. Without our face, we would be stuck in an emot ion less and

depre si ng se lf-ex istence devo id of a prima ry ve hi c le of com munication. As soc ial beings, it is in our very nature to share our expre ion with the out ide world . It i likewise in our nature to subconsciously j udge each face, ass igning certai n traits to parti cular facial characteri tics. One of the most important characteri stics that we judge is "beauty". Interestingly, there is an unusually consistent agreement of what is con idered "beautiful " amongst different cultures, but onl y when we are referring to the face rather than the body, a topic that wi ll be ex plored herein .

BEAUTY OF THE BODY

So what is it that makes a person "beautiful"? Beauty is an arbitrary and abst ract concept that is seemingly difficu lt, if not impossibl e to define. Considering the vast di versity in thi s world and the countless cultures it conta ins, one would expect that surely there must be di ffe rent culturally dependent standards of beauty. However, research suggests that this is onl y parti ally correct.

Research examining the physica l attracti veness of the fema le body often uses the wa ist-to-hip rati o (WHR) as a quantifiabl e measure. Indeed, studies have found that males from most cultures and across history strongly prefer female figures with a low WHR., ln the developed world, hea lthy females have hi gher leve ls of estrogen that cause more fat to be deposited on the buttocks and hips rather than on the wa ist, leading to a low WHR.Thus, the WHR is an indicator of health status and ferti li ty, and male pre ference for low­WHR females is considered an excell ent exampl e o f ma le assessment of mate quality3

Despite the overall preference of men for women with a low WHR, variations do ex ist, thereby casting doubt on the theory that thi s may be a uni versal idea l. Another measure of body habitus is the body mass index (BM !), whi ch is a heuri stic proxy for human body fat. Different cultures and populati ons prefer females of different BMI and WHR due to different sociocultura l influence . Undeniably, the effect of " Westerni za ti on" may be contributing to a more universal standard o f bea uty, but thi is not due to our innate evolutionary preferences. Regardless of these influences, a study comparing fema le phy ica l attracti vene between Japanese and British participants found that Japanese men preferred images of woman with signifi cantl y lower BM!s than Britons and likewi e were mo re re li a nt on body shape when judging ph y ica l attractiveness.

However, the fl aw with these studi es in general is that every culture tested so far has been ex posed to the potentially confounding influence of Western media . A landmark study by Yu and Shepard assessed the WHR preferences of a culturally iso lated population of

Matsigenka indigenous people in Peru, who are located in an exten ive nature park where access is restricted solely to scientific and offic ial visitors and the vast majori ty of natives have never left the premises .3Their results showed that the WHR preferences of males of thi s tribe di ffe red strikingly from those of the United States control population as well a from other world culture , with the "over-weight" female ranking highest in the factors of attractiveness, hea lthiness, and preferred pouse.3

The e were critical finding a they di ffe red striking ly from the pre ferences of ma les in other cultures. The authors suggest that this difference may be due to the fact that in traditiona l societies, physical featu res may play a lesser role because mate choice is limited by kinship rul es, and potenti al mate have access to direct info rmation about mate quali ty, such as age and history of illness.As a result, they do not rely primarily on information inferred from physica l appearance . In contrast, in industrialized societi es, daily ex posure to strangers from an early age may increa e the importance of u ing physica l featu res to assess potential mates based on these factors .3

FACIAL BEAUTY

It seems reasonable to que tion > hether the e relative cultural norms likewi e influence our perception of facial beauty.Counterintuitively, the answer is no. Be fore ex ploring thi s topi c, we must first consider what exactly facia l beauty is and how to define it. The quest to find to suitable defi nition of fac ial beauty date back to antiquity, when the ancient Greeks be lieved that beauty appeared when the ratio of many di ffe rent facial features to each other approached the value I : 1.6 18, the o ca lled golden ratio. However, things are not so simple, as further research has shown that facia l beauty i more a combination of symmetry and an idea l harn1ony of the facia l features with each other. And mo t importantl y, as humans we have an innate mechani sm for detecting this elusive concept of beauty.

Symmetry is an important a pect of facia l beauty and i tied to evo lutionary fitn ess, where le ft-ri ght bilateral symmetry describes hea lth and hi gh genetic quality, and devi ations from it may indicate poor qualities and there fore form a basis for rej ection of a potential mate.,

.There are several exa mple that seem to re inforce this concept. For Instance, supermodels, arguab ly con idered the mo t attractive members of We tern ociety, have the least degree of facial asymmetry when compared to the general population. Facial a ymmetry ex ists a long a gradient in our population and it is clear that we have evo lved to tolerate some degree of thi asymmetry.

Interesting ! ~, studi es ha~e shown that averag ing a random group of. faces results 111 a synthet1c face more attracti ve than any of the ong mal faces .,The faces used in these ana lyses consisted of thirty­two completely random faces from a pool of different cul ture , yet

14 UWOMJ I 80:21 Fall2011

observers always ranked the composite face as be ing the most attractive. Paradox ica ll y, th i suggest that the ideal ham1ony of the fac ial featu res that we consider to be "beautiful " is actua lly as close to "average" as pos ible. Naturall y, such statements have drawn criticism from many indi vidua ls who refu se to be li eve that beauty may in any way related to "averageness".

It is critical to note that the com putationa l "average" of fac ial features that is considered attract ive in thi s case is completely disti nct fro m what cul ture commonl y refers to as an "average" fa ce, whi ch natura ll y has a nega ti ve connotati on and is not conside red "beautiful ". There are certa inly unique and interesting fea tures that may add to the perce ived attract iveness of an indi vidua l's face, but it is important to realize that they must be associated with an "average" face and must be harmonious with the other faci al fea tures.

There have bee n a rguments th at bea uty is a cul tura l phenomenon engrained in us repeatedl y th roughout our youth, resul ting in a bia ed preference such as that of male for females with a low WHR ratio . However, there are many examples that d isprove this theory. Eleven separate meta-ana lyse have revea led very hi gh agreement in fac ial-attracti veness ratings by raters both within their own cul ture, and across other culture ., In fact, the effect sizes were more than double the size necessary to be considered large and thereby strongly suggest a uni versal standard by whi ch fac ial attractiveness is j udged. ln order to negate the possible influence of Western media, a study examin ing preferences fo r fac ia l symmetry between Briti sh individuals and the Hazda, a hunter-gatherer soc iety of Tanzania, likewise found that facia l symmetry was more attracti ve than asymmetry across both cultures.These findings fu rther question the assumpti on that ratings of facial attracti veness and ideals of fac ial " beauty" are culturally unique and are consistent with the fac t that young infa nts prefer to look at face that adults likewi e consider to be attractive.

It is important to realize that there are exogenous fac tors that augment attractiveness and beauty as it pertains to mate selection, whi ch is prec isely why it i such an elusive concept to define. Dutton argues that based on Darw inian aestheti cs, indi vidua ls consciously select mates who have certa in characteristics, and that such characteri stics in fac t may make the person more attracti ve and "beautiful " to them. Dutton further states that it is human personali ty that adds another dimension of beauty, with traits such as a delightful sense of humor and generosity being attract ive. !? Although it is still evolutionarily based on fi nding a healthy mate who is able to provide care, it is thi s rationa l intention combined with physica l appearance that forms a complete view of beauty and attractiveness.

CONCLUSION

Beauty is an elusive concept that is envied and sought by many, yet is extremely difficult to defin e.Aithough the beauty of the body has an evolutionary basis, the concept of the ideal body is a cultural construct that has been influenced and continues to be influenced by culture and media. Conversely, fac ial beauty is a biologicall y ingrained concept based on symmetry and an idea l coalescence of that fac ial features with each other that transcend barri ers of culture, media, and time. Ultimately, concepts of beauty and attracti veness are evoluti onarily based, but cannot be looked at narrowly as based so lely on appearance as they are augmented by exogenous fac tors.

REFERENCES

I. Singh, D. Hum. Nature 1995;6:5 1--68. 2. Fumham, A., Tan, T. & McManus, C. Pers. lndiv. Di ff. 1997;22 :539- 549. 3. Yu DW, Shepard GH. " Is beauty in the eye of the beholder? Nature

1998 ;396:32 1-322. 4. Swami V, Caprario C, Tovee MJ, Fumham A. Female Physical

Attractiveness in Britain and Japan: A Cross-Cultural Study. European Journal of Personality. 2006;20:69-81.

5. Atalay, B. (2006). Math and the Mona Lisa: The art and science of Leonardo da Vinci. New York , NY: Harper Collins Publishers.

6. Steven , M.; Castor-Perry, S.A.; Price, J.R.F. The protective va lue of conspicuous signals i not impaired by shape, ize, or po ition a ymmetry. Behav. Eco l. 2008;20:96-1 02 .

7. Jones, B. C., Little, A. C., Penton-Voak, I. S., Tiddeman, B. P., Burt, D. M., &Perrett, D. I. (200 I). Facial ymmetry and j udgements of apparant health support fo r a "good genes" explanation of the attracti venes -symmetry relationship. Evolution and Human Behavior, 22 , 4 17-429.

8. Za idel, D. W. ; Deblieck, C. Attracti veness of natu ra l faces compared to computer constructed perfectly symmetrica l faces. lnt. J. Neuro ci. 2007, 11 7, 423-43 1.

9. Langlois, J. H., &Roggman, L. A. ( 1990). Attracti ve faces are only average. Psychologica l Science, I (3 ), 115- 12 1.

I 0. Rhodes, G., & Jeffery, L. (2006). Adapti ve norm-based coding of fac ial identity. Vision Research, 46( 18), 2977- 2987.

II . Langlois J H, Kalakani s L E, Rubenstein A J, Larson A D, Hall am M J, Smoot M T, 2000 "Max ims and myths of beauty: A meta-analytic and theoretical review" Psychologica l Bu lletin 126 390-423

12. Langlois et al. "Max ims or Myths of Beauty? A Meta-A nalyt ic and Theore tical Review". Psychological Bu lletin . 2000; 126:390-423.

13. Co hen, J. ( 1988). tati sti ca l power analys is for the behav ioral sciences. Hftl sdale, NJ: Erlbaum .

14. Little AC, Apicella CL, Marlowe FW. Preferences for symmetry in human faces in tv;o culture : data from the UK and the Hadza, an isolated group of hunter-gatherers. Proc. R. Soc. B 2007;274:3 11 3-7.

15. Rubenstein A J, Langlois J H, Roggman L, 200 I "What makes a face attracti ve and why?", in Facia l Att ractiveness: Evolu tionary, Cognit ive and Social Perspective volume I of Advance in Vi sual Cognition Eds G RJ1odes, LA Zebrowitz (Westport , CT: Ablex Publishing) fo rth- comi ng

16. Dutton, D. (2009). The Art Instinct: Beauty, Pleasure, and Human Evolution. New York, NY: Bloomsbury Press.

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UWOMJ I 80 :2 I Fall 201 1 15

Incidence of acute respiratory distress syndrome and acute lung injury in patients requiring prolonged mechanical ventilation

Paul Kudlow, B.Sc. (Meds 2013), Chu L, B.Sc, Herridge MS, M .D., M.P.H

Faculty Reviewer: Nigel Paterson, M .D.

P rimaril y affect ing critical care pati ents, Acute Lung Injury (ALI) and its more severe variant, Acute Respiratory Distress Syndrome (A RDS) are devastating clini ca l syndromes,

h av in g lo n g- te rm functional a nd neurop syc hol og ica l conseq uences I ,2,3. Further characterized by acute hypoxemia, bilateral pulmonary infiltrates on frontal chest radiography, and no clinical evidence of left atria l hypertension, AR.DS/ ALl are severe inflammatory conditions of the lung parenchyma4 ,5. The resulting severe hypoxemia combined with the exten sive release of systemic inflammatory mediators often leads to multiple organ failure; responsible for high rates of morbidity and mortality in the populati on6. Despite many recent advances in our understanding of the pathophysio logy, treatment, and long-term outcomes of ARDS/ ALI , in cidence and preva lence of these conditions remains uncertai n6. The uncertainty in tum reflects the heterogeneity of the syndromes, the lack of de finitions for the underlying disease processes, and fa ilure to uniformly define the population within which pati ents wi th ARDS/ALI are identified5 . The incidence of ARDS/A LI in the United States has been estimated to be around 300,000 ca es per year, but thi s may be an underestimate6. A recent study, conducted by Rubenfeld et al. examined the general ICU population and found the incidence of ARDS/ ALI to be somewhat hi gher, at approxi mately 58.7 and 78.9 per 100,000 respectively; giving an annual estimated incidence at around 141 ,500 and 190,600 cases of ARDS/A LI respecti ve ly in the United States per year6.

The purpo e of the current study was to determine the incidence of ARDS/ALI in a pilot sample from a prospecti ve multi -centre follow-up of critica lly ill patients mechanica ll y ventil ated for at lea t one week - the Towards RECOVE R study? . The incidence of A RDS/ A Ll in patients requiring pro longed mechanica l ventilati on is not known. We hypothes ized that the incidence of AR.DS/ALI would exceed that found in general ICU pati ents, as cited above.

METHODS

As part of the Towards RECOVER study protocol?, pati ents were included if they were ~ 16 year o f age and mechani ca lly ventil ated for at least one week . (n= 82) . Chest imaging was performed dai ly for the first ICU week and each Monday and Thursday therea fter. investigators (PK, LC) underwent systemati c training on Chest X­Ray (CXR) interpretation for ARDS/ ALl by a standardi zed on line educational tutoria lS. CXRs were divided into 4 quadrants, each ana lyzed for the pre ence or absence of bi lateral infiltrates consistent with non-cardi ogenic pulmonary edema. Diagnosis of ARDS/ALl was based on American Europea n Consensus Conference on AR.DS (AECC) guidelines. Data was analyzed to detennine the percentage o f radiograph read independently as ARDS/ ALI by each reader and interobserver variability was be calcu lated (kappa-stat istic)9. All analyses were performed using appropriate so ftware.

RESULTS

The study sample contai ned 82 pat ients . They had a median age 59 year , the male : female rati o was 1.4:1, and 45% of those sampled were found to have ~ 2 comorbidities. The median APACHE II core of wa 25 and a the median ICU LOS of was 37 days. In our study sample, 72% survived until ICU di charge.

To date, the records of 25/82 pati ents have been examined (by both co-authors) for the presence of ARDS/ALI. Of this sample, 2 1/25 (84%) had radi ographic ev idence of bilateral infiltrates and fulfilled AECC criteri a for AR.DS/ALI. Interobserver variability, measured by kappa score, was 0.60 (Figure I).

DISCUSSION

In thi s limited ample, there were a high proportion of patients who fulfilled the criteria for ARDS/ALI. Although there was insufficient data to accurat ly calculate incidence at present, our preliminary proporti on of 84%, ugge t that the incidence of ARDS/ALI in tho e mechanica lly ventilated for at least I week, likely exceeds 58.7 and 78.9 per I 00,000 per on-years respecti vely as previou ly de cribed by Rubenfe ld et a l. in their ampl e of general ICU patients6. Our result were trengthened by relatively good agreement between independent e aluators; we measured a kappa score of 0.60 (Figure I ).

• • • • • ..., • • • •

"' c

i • . N • • • • ....

• • • •

0 • • • •

0 2 3

Les s FULWIO

Figure I. The area of the circ les is proportiona l to the number of subject given a particu lar pair of ratings.

16 UWOMJ I 80 :2 I Fall 2011

Taken together, our preliminary result sugge t that ARDS/ALI are likely under recognized conditi ons, particul arly in cri tically ill patients requiring prolonged mechani ca l ventilation. Earlier tudies have estimated the mortali ty due to A RD I ALl at around 133,500 deaths per year in the Uni ted State 6. Given the possible under recognition however, ARDS/ ALI are conditi ons likely responsible fo r even more deaths in the population. Besides mortali ty, ARDS/ ALI also leads to large amounts of costly and often debi litating morb idity in urviving pati ents and their caregiver I ,3,6. Outcome studi es have consi te ntl y fo und s igni ficant functi ona l and neuropsychological derangement at both I year and 5 years po t illness \ ,2,3. Perhaps better identification of AR.DS/ALJ in the fi r t place may help to more efficiently a llocate hea lth care resources - in tum potentia lly preventing orne of the typica l long-term sequelae currently experi enced by survivors and their caregivers.

Before making any fi rm conclusions however, it should be noted that a lthough the results of our preliminaty study are suggesti ve of under recogni tion of AR.DS/ALI, they are subject to a number of important limitations. Particularl y, thi s study wa not only limited by ample ize, but a lso, data coll ected was subj ect to survi vorship,

selection, and ascertainment biases. Additi onall y, analysi of data collected was limited by the level of training of the independent evaluator (PK, LC). The independent evaluators were tra ined using an online standardized tu torial to a sist in the detennination of bilateral pulmonary infi ltrates as per AECC guideline 5,8. Although good agreement was measured benveen independent evaluators, the data remain to be fo rmall y evaluated by a trained phy ician. Therefore, larger fu ture studies are needed to va lidate and confi m1 the preliminary re ult of thi current tudy.

N arth Perth Family Health Team

Funding provided by the lnstiture of Medical Science. University of Toronto. CIHR, MOH Alternative Funding Plan - Innovation Fund. Acknowledgmenls: We thank Dr. George Tomlinson for his assistance with statistical analysis. As well, thank you to D1: Cathy Tansey, Andrea Malle, and Joel Elman for their assistance 111ith recruitment and data collection.

REFERENCES

I. Herridge et al. "Functional Disabi lity 5 years after Acute Respiratory Distress yndrome." New England Journal of Medicine. 20 II ; 364: 1293- 1304

2. Hopkins et al. " europsychological equelae and Impaired Health tatu in Survivors of Severe Acute Respiratory Di stress Syndrome." American Journal of Respiratory and Critical Care Medicine., Volume 160, umber I, Ju ly 1999, 50-56

3. Herridge et at. "One Year Outcomes in urvivors of the Acute Respiratory Distress Syndrome." New England Journal of Medicine 2003; 348: 683-93 .

4. Ware et el. "The Acute Re pi ratory Distress Syndrome." New England Journal of Medicine. 2000; 342: 1334- 1349

5. Bernard et ai."The American European onsensus Conferenceon ARDS. Defi niti on , mechani sms, re leva nt outco me , and c lini ca l tri a l coordinati on." American Journal of Respiratory and Crit ical are Medi ci ne. 1994 Mar; 149 (3 Pt I): 818-24.

6. Rubenfeld et al. " Incidence and Outcomes of Acute Lung Injury." ew England Journal of Medicine. 2005; 353 : 1685 -1 693

7. Herridge et al. ''Outcomes and Need Assessment in the Intensive are Unit (ICU) Surv ivors and Their aregivers (RECOV ER)'' Retrieved online April 17 20 II . http://clinicallrials.gov/ct2/show CT00896220? term=towards+recover&rank= I H ypothe is Wehypothesizethanheincidenc

eo fA RDS/ A Ll exceeds58. 7and78.9pe 8. Rubenfeld. "Improving the Radiographic Diagnosis of Acute Lung Inj ury"

University of Wa hington. Retrieved online Apri l 17 20 II. http:// depts. wash i ngton.edu/kcl i p/about.shtml

9. Rubenfeld et al. " lnterobserver Variab ili ty in Applying a Radiographic Defi nition of ARDS" Chest. 1999; 11 6: 1347- 1353

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UWOMJ I 80 :2 I Fall 2011 17

Shortness of breath in a 12 year-old boy: a classic presentation of stage IV Hodgkin's Disease?

Michael Livingston (Meds 2011)

Faculty Reviewer: Dr. Neil Merritt, M.D., FRCSC

S hane is a 12 year-o ld boy who presents to your offi ce with worsening shortness of breath on exerti on. Hi s fa ther ex plains that hi s son had severe asthma when he was younger. He wa

adm itted to hospital when he was 2 years old and put on a vent ilator in the intensive care un it when he was 4. Hi s symptoms have been much better since then. In fac t, Shane hasn't had to use puffers very much at a ll up until a few month ago. He started u ing Yentoli n again while playi ng soccer and does get some relief with thi s.

IS IT ASTHMA?

You take a thorough history from Shane 's father. He notes that the shortness of breath has come on gradually over the last few months to the point where it causes Shane diffi culties several times per week. There is no hi story of producti ve cough, and no fever, night sweats or weight loss. Shane has no other medi cal conditi ons, no known allergies, no previous surgeries, and his vaccinations are up to date. Hi parent are from Barbados but he ha never been out of the country himself. Shane 's 13 year-old brother had a cough recentl y but there are no other sick contacts.

On examinat ion, Shane is a lean-looking child but otherwise appears well. Head circumference and height are above the 50th percentile and weight is above the 25th percentile. He has no cerv ica l, suprac lav icul ar, infrac lav icul ar, ax ill ary, or inguina l lymphadenopathy. His respiratory exam is significant for mild wheeze throughout but no crackl es or areas of decreased breath sounds.

You explain th at Sbane's symptoms most like ly repre ent worsening asthma. You give Shane a prescription for inhaled steroid and encourage him to use it tw ice per day. You also give him a re fill for Vento! in and explain that he can use it whenever he fee ls short o f breath . Shane's father agrees to foll ow-up with you in one month .

IS IT INFECTIO US?

You see Shane and hi s father back in clinic one month later. Hi s father looks very concerned. The hortness o f breath co ntinues to be an issue and now Shane has a rash. The rash sta rted behind hi s knees and has spread to hi s trunk, arms, and neck. The rash is pruritic and bothers Shane quite regularly.

You do a full review o f systems and di scover than Shane has been feeling generall y un we ll recentl y. He reports no night weats, fever, or weight loss, and no pain at night. Examinati on o f the rash revea ls numerous crusted papu les measuring 3-5 mm in diameter (see Figure I). Hi s father assures you that Shane has already had chi cken pox. The phys ical examinati on is otherwi se the same as Shane 's prev ious visit. There is no lymphadenopathy and the mild wheeze heard on respiratory exam is unchanged. You prescribe hydrocorti sone cream for the rash and set up an outpati ent re ferral to In fec ti ous Disease.

Figure 1. Crusted papules measuring 3-5 mm consistent with pityriasis lichonoides [ 4).

WHAT ELSE CO LD IT BE?

hane is seen by your co lleague in Infectious Di ease six weeks later. hane has now deve loped a dry cough. The rash is till present

although the itchine s i re lieved so mew hat by the topi cal hydrocorti sone. A rev iew o f systems reveal s that Shane has now lost about 5 pound since the worsening of shortness of breath began .

hane deni es feve rs and night sweats, but hi s father ays that, "he's been feeling rea ll y unwell recentl y." Physical examination reveals anteri or cervica l and supraclavicular lymphadenoapthy. The nodes are nontender, rubbery and range in size from 1 to 2.5 em. Respiratory exam is s ignificant for wheeze but there are no crackles or areas o f decreased breath sounds.

Your colleague ex plains that he needs to get a chest x-ray as part of hi s workup . He agrees that Shane is quite sick and will need more te ts. He sends Shane to the Pediatric Emergency Department for furth er eva luation .

HOW BAD IS IT?

Shane is as essed in the Emergency Department later that afternoon . He has a fever of 38 .5 degrees Celsius, tachycardia with a heart rate o f I ~5 ~ and oxygen saturation of 94% on room air. The Emergency Phys1c1an orders a chest x-ray (see Figure 2) and bloodwork. The chest x-ray reveals mass- like pulmonary opac ities in both lungs and enlargement o f the hila and superior medi astinum .

B loodwork is s ignifi cant for a white b lood cell count of 32.0 ~hich con ist o f 24.0 neutrophil s and 4 .1 eosinophil s. Hemoglobi~ IS decreased s lightl y at 129. Platelets are elevated at 55 1 C reacti ve protein is 111 .8, and erythrocyte sedimentation rate i '54. Lactate dehydrogenase is high at 61 6 but urate and calc ium are normal.

18 UWOMJ I 80 :2 I Fall 2011

Figure 2. Chest x-ray of a 12 year-o ld boy, howing a medi a tina] mass, hil ar enlargement, and patchy mass- like opacit ies in the lungs.

Shane is admitted to hospital by the inpatient Ped iatrics team for further workup. The differentia l includes infection, va culiti , and ma li gnancy. He is placed on airborne contact precauti ons and admitted to a negati ve pres ure room until tubercu losis can be rul ed out.

IS IT CANCER?

Shane undergoe a CT scan of the pelvis, abdomen and thorax the following day (see Figure 3). The CT revea ls multiple solid nodules in both lungs, as well as mediastinal and hil ar lymphadenopathy. Enlarged nodes are seen in the para-aortic area but there are no signs of a primary tumor.

General urgery in consulted to obta in a biopsy. Shane and hi s parents remai n anxious over the next few days as they wa it for a spot to open up in the operating room. In the meantime, Shane's white blood cell count remains in the hi gh 20s and plate lets rise up to 762 . Shane goes to the operating room three days after hi s admission for biopsy of a superficial supraclavicular lymph node and skin under genera l anesthetic. Frozen section of the lymph node is pos iti ve for malignancy but fl ow cytometry is normal. A definite diagnosis is deferred until permanent sections can be processed.

Over the next few days, Shane's shortness of breath worsens. The vasculitic bloodwork comes back normal and acid-fast cultures are negati ve for tuberculos is. The fina l pathology report i relea ed one week later indicating Hodgkin 's Disease, Nodular Scleros ing subtype.

IS TIDS STORY TYPICAL FOR HODGKJN'S DISEASE?

Shane's story may seem somewhat convo luted but hi s symptoms are actually quite typical. In children, less than 20% of patients present with one of the classic "B" symptoms of Hodgkin 's Disease (weight loss, fevers, and drenching night sweats) [ 1] . In fact, the most common presentation in children consists of painless cervical lymphadenopathy (which occurs in 70-80% of cases) and/or a mediastinal mass (in 50% of cases) [2] . Shane's initial chief complaint was shortness of breath due to the mass effect of mediastinal lymphadenopathy. This eventual ly progressed to a cough and hypoxia. The lesions in the lungs represent a combination of

Figure 3. Computed tomography scan of the thorax showing masses in the lungs and hil ar and medi stinallymphadenopathy.

contiguous spread from hilar lymphadenopathy and metastases to lung parenchyma [3].

The rash and itchiness that Shane ex perienced isn' t that unusual either. In fact , some patients will give a hi story of insid ious itchiness for months before being diagnosed wi th Hodgkin 's Disease [2] . The sk in les ions in thi s case most li ke ly represented pityriasis lichenoide , which is a sociated with lymphoma [4].

Shane 's initial blood work is classic fo r Hodgki n 's Disease. At first glance, the elevated white blood ce ll count consisting almost entirely of neutrophil s would seem to suggest an infectious etio logy. This is certa inly supported by the hi gh platelet count, C reacti ve protein, and erythrocyte sedimentati on rate. (Indeed, in this case, Shane remai ned on airborne contact precauti ons until tubercul osis was fonnall y ruled out with a negative acid- fast bacilli culture.) Neverthe less, a complete blood count characteri zed by neutrophilia, eo inophili a and thrombocytos is is cia sic for Hodgkin 's Disease in children, and is not due to underl ying in fec ti on [I , 2, 5].

The presence of elevated lactate dehydrogenase would lead to some suspect tumor lysis syndrome. The elevated levels seen in thi s case ac tuall y represent a hemolytic anemia, which is not uncommon in Hodgkin 's Disease [6]. The normal serum electrolytes and urate leve ls seen here stand aga inst the presence of ongoing tumor lysis.

WHAT lS THE PROGNOS IS?

Shane has stage NB Hodkin 's Disease according to the Ann Arbor Staging Class ificati on [5]. He has diffuse invo lvement of I or more extral ymphati c organs (stage IV) and has 8 symptoms (B). This places Shane in the hi gh-ri sk category [5, 7]. Even so, with proper treatment and monitoring the 5-year survi va l for children like Shane is up to 90% [7 , 8]. Shane was started on induction therapy whil e in hospita l, consisting of cyc lophosphamide, vincri stine (Oncovin), procarbazine, and prednisone (COPP). He was di scharged home once hi s breathing improved and will complete three more courses of treatment before rece iving radiati on therapy.

UWOMJ I 80:2 I Fall 2011 19

REFERENCES

I . Gottschalk SM, McClain KL (20 I 0) Overview of Hod kin lymphoma in children and adolescents. UpToDate. www uptodate com.

2. Hay WW, Levin MJ , Sondheimer JM , Deterding RR (2009). Current Diagno is and Treatment Pedi atri cs, 19th Ed. The McG raw-Hill Companies, Inc. : New York.

3. Andreoli TE, Carpenter CCJ, Griggs RC, Loscalzo J (2007). Ceci l E entials of Medicine, 7th Ed. Saunders : Philadelphia.

4. Klein PA (20 I 0). Pi tri a i s Lichenoides. eMedicine . emedicine.medscape.com.

5. Kliegman RM, Marcdante KJ , Jenson HB, Behrman R.E (2006). el on E en ti a! of Pediatrics, 5th Ed. El evier aunders: Philadelphia.

6. McMillan JA , Feigin RD. DeAngeli C, Jones MD (2006). 0 ki' Pediatrics. Principles and Practice, 4th Ed. Lippincott, Williams & Wilkins: Philadelphia.

7. Schwartz C L (2005). Special issues in pediatric Hodgkin 's di ease. European Journal of Hematology upplement 66: 55 .

8. Foltz, LM, Song, K W, onnors, JM (2006). Hodgkin's lymphoma in adole cents. Journal of C linica l Oncology 24:2520.

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20 UWOMJ I 80:21 Fall2011

Schulich MEDICINE & DENTISTRY

Obstructive sleep apnea in children: the when, how and why of screening

Kirsten Jewell, BSc, BPHE (Meds 2012)

Faculty Reviewer: Dr. Murad Husein, Department of Otolaryngology, UWO

0 bstructive sleep apnea syndrome (OSAS) is part of the spectrum of sleep disordered breathing (SOB) and is estimated to occur in about 2% of the pediatric population ,1

whereas 2-5% of adults are affected 2 The peak incidence of OSAS is in pre-schoo lers, when ton illar hypertrophy i most common .3 Like adu lt OSAS, pediatric OSAS is caused by periods of complete or partial upper airway collap e during leep, disrupting nonnal sleep patterns and resu lting in intennittent hypoxia during apne ic and hypopneic episodes. It i believed that OSAS results from a combination of anatomic abnormalities resulting in decreased space and increased pressure in the upper airway, and neuromuscular or funct ional abnorma lities that cause decreased muscle tone wh il e sleeping and lead to periodic a irway co ll apse.3•4

There is an increas ing awarene s about the preva lence and consequences of OSAS in the adult population among primary care physic ians, a llowing for improved screeni ng, diagnosis and treatment. 5 However, the recognition of thi s disorder in the ped iatric population is much more difficult, and current screening among primary care physicians is inadequate 6 Children with OSAS present with different symptoms, have different ri sk factors , different pathophysio logy, and require different management strategies than in adults.4•5.7

CLINICAL IMPORTANCE

OSAS in chi ldren has been shown to contribute significantly to childhood morbidity with consequences seen in multiple systems.The severity of sleep apnea has a dose-dependent re lationship with decreased left ventricular function leading to congestive heart failu re and cor pulmonale. 1 Plasma C-reactive protein level , a marker of inflammation with an important ro le in atherogenesis, have a lso been shown to be elevated in children with SDB,8 and fasting in ulin levels a lso seem to correlate with the disease severi ty, independent of BMJ.9 Failure to thrive and a low weight index have been noted in children with OSAS, possibly due to changes in hormonal release during apneic episodes. 1o

It is known that OSAS in adu lts resu lts m daytime hypersornnolence and psychological seque lae such as di sturbed

concentrat ion and memory,2 however in ch ildren the deficits in neuropsychologica l and behavioural functioning caused by untreated OSAS can severely affect development, interfere with learning, and cause symptoms that may be diagnosed as attention-deficit hyperacti vity disorder (ADHD). In one well-known tudy, it was found that 33% of chi ldren with ADHD exhibited symptoms of SOB while only about I 0% of children without AD HD in the study exhibited such symptoms, with the authors postulat ing a causa l relationship .11 This hypothe is has been strengthened by the finding that symptoms of inattention and hyperactivity predictably improve after surgica l treatment for OSAS.12

DIAGNOSIS

RJSK FACTORS

Obesity is a common ri sk factor in both adu lts and children, as increased fatty tissue in the neck resu lts in increased upper airway resi tance. 13 However in childrenOSAS is sti ll most common ly related to adenotonsillar hypertrophy.3.7 Obstructive leep apnea is also assoc iated with other medica l disorders such as Down syndrome, anatomic crani ofac ial abnorn1a li ties such as micrognathi a, neuromuscular disease including cerebral palsy, and conditi ons such as sickle cell disease and laryngomalacia. 1 Children with any of these conditi ons should be seen as high-ri sk and carefu ll y screened.

HISTORY

A thorough sleep hi story should be taken from the parents , aski ng spec ifica lly about I) snoring, 2) apneic episodes,3) laboured mouth breathing, and 4) restlesness.3 Habitual (nightly) snoring is the most sen iti ve indicator, as OSAS is rarely seen in its absence. I However, snoring occurs in up to 12% of chi ldren and therefore ha poor spec ificity. I Differentiati ng between primary noring and OSAS can be difficult based on hi story alone. Note that the loudness of snoring does not necessaril y corre late to the degree of obstruction ! 1

Dayt ime symptoms may include excessive daytime sleepi ness, or more commonly, hyperactivity with attention and concentrat ion prob lem , possibly resulting in behavioura l difficulties and learning prob lems. The Canadian Paedi atric Society and Coll ege of Fami ly

Table 1. Differences in the C linical Presentation ofOSAS between Children and Adults

C hildren Adults Most Common Ri sk Factor rronsillar hypertrophy Obe ity

Obesity is secondary) Daytime Symptoms Hyperacti vity!Jnattention !Daytime sleepiness

Epidemio logical Distribution 1:1 Males to Females ~ : 1 Ma les to Females Polysomnograph Findings !Awakening during REM sleep !Awakening during slow-wave sleep

Fewer arousa ls More arousals Most Common Treatment Surgery (adenotonsi lectomy) CPAP

UWOMJ I 80 :21 Fall2011 21

Physicians of Canada endorse the Greig Health Record which recommends asking about s leep habits, daytime somnolence as well as concentration and irritabili ty at a ll periodic hea lth visi ts for children ages 6-17. 14

The ' BEA RS' screening questions, a user-fri endl y too l that encourages obta ining sleep informati on from pediatric patients, has been shown to increase the likelihood of identifying s leep problems in a primary care sett ing, 15 although it has not been va lidated to spec ifi cally identi fy OSAS.

PHYSICAL EXAM

Adenotonsillar hypertrophy may be u pected on phy ica l exam by the observation of mouth breathing, hyponasa l speech, or direct visualizati on on examination of the oropharyngea l cav ity, I a lthough visual inspecti on may give a fa lse impress ion of tonsill ar s ize and is therefore not a re liable method of diagnosis.1 Referral to an otolaryngologist wi ll a ll ow closer visualizat ion of the tonsil s, adenoids, tongue base, and soft palate through fl exible laryngoscopy, and may detect subtl e structural abnormalities in the airway.

Recognit ion of risk factors for OSAS such as craniofacial abnormalitiesor obesity on physical exam may also increase the clinician's suspicion of the diagnosis.

FURTHER TESTING

Audi otapes or videotapes taken by the parent of the sleep ing child may sometime be used by healthcare team to li ten and watch for observable apneic episodes. tudies examining the reliability of this method of testing have found mixed results w ith genera ll y poor predictive values 3 While this is a non-invas ive and available means of creening and may be of orne use to c lini cians, if the results are negative and you are still suspi cious of OSAS in a patient, they should be referred for a sleep tudy.

The go ld standard for di agnosis of OSAS is a sleep study, or polysomnography. It will re liabl y differentiate between primary snoring and 0 AS, and can determine the severity of the syndrome. Results mu t be interpreted based on age-adjusted criteri a, as OSAS affects sleep patterns in children di ffe rentl y than in adults. 1 Children wi th OSAS ex perience greater obstructi on during REM sleep, 16and have fewer arousals associated with apneic epi sodes.7 Children also experience greater desaturation during apneic epi odes.3 Theduration of obstructi on req uired for a definition of apneaand the threshold number of apneic episode for a diagno i of a di order must be adjusted due to the increased respiratory rate seen at base line in children, and it is common to see hypoxia due to prolonged parti a l obstruction rather than the cyc lical complete obstruction seen in adults. I Thi s is known as obstructive hypoventil ation.

Worldw ide, the demand for polysomnography i high but provi sion is limited and is costly. Therefore it is often diffi cult to obtain thi s test in a timely fashion 3 In the absence of an eas il y accessible s leep lab, ni ght oximetry testing may be con idered, measuring epi sodes of desaturation throughout the night with an 0 2

saturation probe on the child 's finger. Thi s te t genera lly ha a good pos iti ve predicti ve value, but if it is negati ve the patient should sti ll undergo poly omnography to rul e out OSAS. 17

MANAGEMENT

Adenotonsillectomy is usually the most appropriate therapy for children with OSAS. In children with documented adenotonsillar hypertrophy, 75 to I 00% wi ll have symptom resoluti on as well as normal polysomnograph results afte r surgery.1 Patients with obes ity or uncorrected crani ofacia l abnormalities may see poorer results on post-operati ve polysomnography.1

"BEARS" Screening Questions: B=Bedtime Issues E=Excessive Daytime Sleepiness A= Night Awakenings R=Regularity and Duration of Sleep S=Snoring

Studies have repeatedl y shown dramatic improvements in quality of life sco res, behavioura l symptom s, depression , hyperacti vity and somatization for children with OSAS after adentons ill ectomy. 18 Interesting ly, children w ith milder form s of sleep di sordered breathing also show imilar improvements after the

surgery.

As with a ll therapies, the ri sk of the procedure must be considered. The mo t serious ri sks of adenotonsillectomy include respiratory complications, and it is thought that patients with more evere OSAS on polysomnography pre-op are more likely to

ex perience respiratory compromise post-op. 12·18-20 Therefore these patient hou ld be ho pitalized overnight and monitored carefully post -operatively.

For patients with incomplete resolution of symptoms after surgery, or for those patients w ho are not surg ical candidates, continuou posi tive airway pressure (CPAP) therapy has been shown to be effecti ve. 1 However, it i often not tolerated in the younger population and must be frequent ly adju ted to fit the growing child, resulting in poor compliance.

lt is a lso important to assess for and treat behavioural sleep di sturbance in children diagnosed wi th OSAS, e pecially those that continue to have daytime symptoms. Behavioural sleep di sturbances including bedtime resi tance, problematic leep a ociation , and prolonged nocturnal awakeni ngs, have a high co-morbidity with OSAS in children, and independently put the child at an increased risk for neurocognitive and behavioural issues.21 Therefore it is important to implement behavioural interventions while concurrently invest igating and treati ng for OSA

SUMMARY

Primary care phy icians have an important role to play in the identificat ion and diagnosis of OSAS in children. However sleep di sorder are underdiagnosed in primary care practices, primarily because physicians do not ask parents about the symptoms of di sordered leep. In general, it i difficu lt to accurately diagnose OSAS on hi story and physical examination alone. However, primary ca re phy icia ns should be performing reg ular creening for symptoms of OSAS as recommended by American Academy of Pedi atri cs. noring is the most sensitive indicator. If clinical suspic ion is hi gh based on risk factors and/or hi story and phy ical examinati on, the chi ld hould be referred to an otolaryngolog ist or direct!~ to polysomnography for further testing. Complex patient , mcludmg mfants and those with congenital abnormalities, should be refened to an otolaryngologi t. It is important to identify and treat pediatnc O~AS early in order to prevent serious morbidity, including neurobehav10ural sequelae such as symptoms of inattentiveness and hyperactivity.

REFERENCES

I. American Academy of P~di atri cs. Clinical practi ce guide line: diagnosis and management of childhood obstructive sleep apnea syndrome. Ped iatrics. 2002; I 09(4):704-12.

2. Chung A, Jairam S, _Hussain MRG , hapiro M. How, what, and why of sleep apnea. Perspectives for pnmary care phys ic ian . an Fam Phys ician. 2002 ;48 : I 073-80.

22 UWOMJ I 80 :2 I Fall 2011

3. Balbani AP , Weber AT, Montovani JC. Update in ob tructive leep apnea syndrome in children . Rev Bra Otorrinolaringol. 2005;71 ( I ):74-80.

4. Powell , Kubba H, O ' Brien C, Trem len M. Paediatric obstructi ve sleep apnoea. Clinical Otolaryngology. 20 I 0;35(5):4 18-23.

5. Erler T, Paditz E. Ob tructi ve sleep apnea syndrome in children: a slate­of-the-art review. Treat Respir Med . 2004;3(2): I 07-22 .

6. Meltzer LJ , John on C, Crosette J, Ramos M, Mindel! JA . Prevalence of diagnosed sleep disorders in pediatric primary care practice . Pediatrics. 20 I 0; 125(6):e 1410-8.

7. Choi JH , Kim EJ. Choi J, et al. Obstructive leep apnea syndrome: a child is not ju t a mall adult. Ann Otol Rhinol Laryngol. 20 I 0; 11 9( I 0):656-6 1.

8. 8. Tauman R, lvanenko A, O' Brien LM , Gozal D. Plasma -reacti ve protein levels among children with Jeep-disordered breathing. Pediatrics. 2004; 113(6):e564-9.

9. 9. Eva RC de Ia, Baur LA, Donaghue K , Waters KA . Metabolic correlates with obstructi ve sleep apnea in obese subjects. J Pediatr. 2002; 140(6):654-9.

I 0. I 0. Nieminen P, Lopponen T, Tolonen U, et al. Growth and biochemical markers of growth in chi ldren with snori ng and obstructi ve sleep apnea. Pediat ri cs. 2002; I 09( 4):e55.

II. II . Chervi n RD, Dillon JE, Bassett i C, Ganoczy DA, Pituch KJ . Symptoms of sleep disorders , inattention, and hyperactivity in child ren. Sleep. 1997;20( 12): 11 85-92.

12. 12. Mitchell RB, Kelly J. Behavioral change in children with mild sleep­disordered breathing or obstructive sleep apnea after adenoton illectomy. Laryngo cope. 2007; 117(9): 1685-8.

13. 13. Verhulst SL, Van Gaal L, De Backer W, Desager K. The prevalence, anatomical correlate and treatment of sleep-di ordered breathing in obese children and adole cents. Sleep Med Rev. 2008; 12(5):339-46.

14. 14. Greig A, Constantin E, Cars ley S, Cummings C. Preventive health care visits for children and adolescents aged six to 17 years: The Greig Health Record- Executi ve Summary. Paed iatr Child Hea lth . 20 I 0; 15(3): 157-62.

15. 15. Owens JA , Dalze ll V. Use of the " BEARS" sleep screening tool in a pediatric residents' continuity clinic: a pilot study. Sleep Med. 2005;6( I): 63-9.

16. 16. Muzumdar H, Aren R. Diagnostic issues in pediatric obstructi ve sleep apnea. Proc Am Thorac Soc. 2008;5(2):263-73 .

17. 17. Wong T. Polysonmnography in Chi ldren : 2006 Update. HK J Paediatr (New Series). 2007; 12( I ):42-46.

18. 18. Ye J. Outcome of Adenotonsillectomy for Obstructive Sleep Apnea Syndrome in Chi ldren. Ann Otol Rhino I Laryngol. 20 I 0;(8):506-5 13.

19. 19. Mitchell RB , Kelly J. Quality of li fe after adenotonsillectomy for SDB in children. Otolaryngol Head Neck Surg. 2005; 133( 4):569-72.

20. 20. Tran K.D, Nguyen CD, Weedon J, Goldstein NA . Child behavior and quality of life in pediatric obstructive sleep apnea. Arch Otolaryngol Head Neck Surg. 2005; 131 ( I ):52-7.

2 1. 21. Ye J, Liu H, Zhang G, et al. Postoperative respiratory complication of adenotonsillectomy for obstructive sleep apnea syndrome in older children : prevalence, ri sk factors , and impact on clinical outcome. J Otolaryngol Head Neck Surg. 2009;38( I ):49-58 .

22. 22. Byars K, Apiwattanasawee P, Leejakpai A, Tangchityongsiva S, Simakajomboom N. Behavioral sleep disturbances in children clinica lly referred for evaluation of obstructive sleep apnea. Sleep Med. 20 II ; 12(2): 163-9.

UWOMJ I 80 :2 I Fall 2011 23

An interdisciplinary approach to voice disorders

Emma Farley (Meds 2013), Ashley Kim (Meds 2013)

Faculty Reviewer : Dr. K. Fung

T he larynx serves the dual purpose of airway protection and phonation. It is covered by the epig lottis during swallowing, and i patent during re pirat ion and phonation, during which

a ir passes past the modified sides of the larynx, the voca l folds or cords. The upper border of the conus e lasticus is thi ckened, which forms the true vocal fold s. Histologically, the outermost layer of the voca l fold is campo ed of tratified squamou epithe lium . Deep to this li es the lamina propri a, a fl exible fibrou s layer contai ning e lastin, collagen, and fibroblasts. The lamina propria is divided into three c linically important layers - superficial , intermediate and deep, which become gradually more stiff a the co ll agen to e lastin ratio increases. Deep to this membranous cover lies the body of the thyroarytenoid muscle.

Phonation requires the presence of not on ly the vibratory voca l folds, but other upper airway structures - the pharynx, ora l and nasal cavities - for resonance and articu lation . Phonation is produced during the g lotti s cycle. The first step is the accumulation of air pressure beneath the approximated voca l fo lds. At a particular pressure, call ed the phonation threshold pre sure, the voca l fold s begin to part in a wave- li ke fashion from inferior to superior. The voca l folds are s imultaneous ly moved laterally by the a ir column, and quickly return to the midline due to the ir intrinsic e lastic properties. Thi cycle repeats approximate ly I 00 times per second in men and 220 times/second in women 1. The amplitude, frequency, wave morphology and periodicity (volume, pitch and voca l quality, respecti vely) are va ri ed by changes in a ir pressure and/or ti ssue quality. Amplitude is increased or decreased by providing a greater or lesser ex haled force , paired with an in crease or decrease in tens ion of voca l fo lds (affected princ ipa ll y by the thyroa rytenoid mu c le) . Pitch is increased by contraction of the cricothyroid musc le, which lengthens and thin the voca l fold , and decrea ed by contract ion f the thyroarytenoid muscle, whi ch shorten the fold and increases the ir mass .

Di sorders of and di sruption s to the voca l folds may have devastat in g co nsequ ence in eve ryday co mmuni ca ti o n, a nd especially for those who re ly on thei r vo ices profe s iona lly. T hi arti c le wi ll address some of the most common voca l di sorders of profess iona l s in gers, th e ir ca use, identi fi cation , management, prevention , and the ro le of a multidi sc iplinary team in mainta ining voca l hea lth .

VOCAL HYGIENE AN D T H ERAPY

First- li ne treatment for many organi c voca l disorders, such as nodu les, po lyps and cysts is voca l therapy. Vocal therapy serves to impro ve voca li za ti on techn ique , a nd to minimi ze harmful behaviours, whil e maximi zing hea lthful one . Holmberg et al. used voice the rapy in the treatment o f vocal fo ld nodul es, and showed perceptual improvement in voca l qua li ty, and reduction in nodule

size2 Their protocol for vocal therapy cons ists of 5 d ifferent approaches to vocal health, and it was concluded that the therapy as a whole is required to significantly improve vocal quali ty2. The first is voca l hygiene, which enta ils patient education on normal phonation, types of abu ive behaviours (voice overuse) and abusive substances (smoke and caffeine), and etiology and consequence of vocal nodules. The second i re piration - a focus on reducing the effort of speech breathing and exercises to tra in the proper management of air supply. Third are direct faci litation mea ures which aim to reduce loudness, coup led with "yawn-sigh" exercises, w hich relaxes vocal musculature and so ften vocal onset. The fourth is relaxation techniques and stress management. Last, the patients were instructed to carry over all of the above techniques to real ituations2. One randomized control trial demonstrated the efficacy of voca l therapy in pati ents who acquired voca l impairment after treatment (either laser o r radi o therapy) for early g lo ttic cancer. Significant impro ement were no ted bo th subjective ly by patient questionnaire and through objective vo ice parameters3.

A econd e lement in voca l technique is the voca l warm-up. Warm-up exerc ises inc lude !retches of the face and torso, deep breathing tri gger , sustaini ng vowel on various pitches wi th varyi ng intens ity, humming and lip-buzzing, g lide , and the production of con onants. The a im of the wann-up is to maximi ze phonation, resonance and respira tion. Elli ot e t al. , hawed that voca l warm-up reduces vi cos ity of the voca l fo lds, but that this result a lone does not uniforml y increase ea e of phonati on (phonation thre hold pres ure) among subjects4

• It is in tead hypothe ized that the voca l warm-up affect othe r properties of the voca l fold s, uch as amplitude, vibrati on peri odic ity, and nervous cont ro l of laryngea l muscles4.5.

Bay lock conducted pre liminary research that studied the effect of voca l-wam1 up in four ubj ects with vo ice di sorders6. He reported a s ignifi cant improvement in voice production accordi ng to acou tic mea ures and se lf- rating, but noted that more studies were needed to corroborate these re ults6 A recurring prob lem in the li terature seems to be the inte r-subject variab ili ty in vocal physiology, and the d ifficu lty o[ findin g an adequate measure to asses the different effects of the warm-up4

•5•6. Therefore, the efficacy of wam1 up in vo ice di sorders is still inconclusive.

A third cons iderati on in the management of any voca l di sorder is the prompt treatment of secondary dysphonia . Examples are acid reflux , acute laryngiti s, and a ll ergic laryng itis . One of the mo t important c~uses that should be ruled out is laryngopharyngea l re flu x (LPR). Un hke the stomach the larynx does not have the intrinsic ability to protect from gastric acid re lated muco a l damage7.11 . In add1t1 o~ to the mherent u ceptibility of the la rynx to aci d damage, carb~mc a~hydrase type 3 ( important in regulating pH by producing a lkalme bicarbonate) IS normall y present in true voca l fo ld however, dimini shed or absent in voca l fo lds affected by LPR7. The '

24 UWOMJ I 80 :21 Fall2011

symptoms of LPR include throat clearing, hoarseness, excessive mucus, cough, globus sensation as well as laryngoscopic findings which include posterior laryngeal edema, true voca l fold edema, and p eudosulcus9•

11(Figure 2). The genera l approach to the treatment of LPR is simi lar to the treatment of gastroesophagea l reflux9. Dietary modifications consi t of limi ting foods and beverages containing caffeine, alcohol and peppermint, which may weaken lower esophagea l sphincter tone 11 . The ev idence surrounding the use of PPis for the management of LPR remains somewhat inconclusive9- 11 . However, for patients with LPR who have symptoms that impact their profess ional or socia l responsibilities (like singers, actor , lecturers), it is recommended that treatment with PP!s be started at high do es 11 , as well a administration of H2 blocker and antacids when reflux is anti cipated after meals9

In all cases of voice di sorders, a multidisciplinary team consisting of oto lary ngo logis ts, family physicians, speec h pathologists and voca l teachers are required . While speaking voice is sometimes unaffected by voca l fold lesions, the reduced vocal range, increased effort and impaired endurance experienced by professional singers, have far greater implications to their ca reer12. The pos ibility of secondary causes of dysphonia such as LPR, hi ghlight the significance of a thorough hi story and physical , which can revea l risk factors and possible etiologies that lie outside the larynx. The role of the family physician is parti cularly important in isolating and directing appropriate treatment or referratl 4 The role of the speech language pathologist lies in the education of regul ar speech, assisti ng in phonati on, articu lation, respiration and resonance12 Voca l teachers contribute specia lized experti se in vocal hygiene, wam1 ups and education of proper singing techniques, as well a profess ional guidance. Not surpri singly, it is wide ly appreciated that combined interdisciplinary treatment modalities support better outcomes for patients 12-14.

PROBLEMS FOR SINGERS: VOCAL FOLD LESIONS

Benign vocal fold le ion are common in profe sional vo ice u er . The most likely culprit of these lesions include voca l overuse, misuse (excess ive musc le tension) and ab use (voice ove ru se or whispering) 15. During any of these acts, there is excess ive mechanical stress applied to the voca l folds. The mechanica l stres of excess ive vi brations of the voca l fold affect the voca l fold mucosa itself, rather than the underl yi ng musculature16·17, resulting in fatigue damage18. Vocal ti sue traumatized by repeated co lli sion forces, vocal fold accelerations and decelerations, and heat di ssipation, which result in tissue breakdown and remodelling16·17·19 The remodelling phase induces mass lesions, including voca l fold nodules, polyps and cyst . While the histo logy and pathology of benign vocal lesions is not fully understood, some studies try to correlate the different types in order to detem1ine the best pos ib le management15.

Vocal polyps are benign, hyperplasti c lesions of the laryngea l mucosa. They are normall y si tuated unilaterall y20 and anteri orl y on the vocal fold21. It is hypothesized that voca l polyp are due to areas of vibration-induced hyperaemia and vasodil ation resulting in edema21 . The edema then leads to degenerati on or fibrosis21. Vocal polyps are also associated with smoking and acid reflu x22 . First-l ine treatment is generally regarded to be voca l behav ioural therapy' S, but debate remains over whether patients should primarily attempt voca l therapy measures (as in the case of voca l fold nodule ), or proceed immediately to s urgica l inte r ve nti o n . A we ll-d efin ed microphonosurgery ex ists, developed by Hochman and Zeitels, which preserves more of the voca l fold microstructure than typical cold instrument or laser removal22 . Stajner-Katusic et al. , in vestigated the vocal quality of fi ve males, before, one month after and six years after surgical vocal polyp removal. Their data showed significant improvement of vocal quality across several voca l measures,

including elf-estimation by the participants23 . Conversely, Cohen and Garrett showed that voca l therapy was effect ive in improving voca l quality, by reducing the size of voca l polyp (but not eliminating voca l polyps) in 50% of their participants, while the other half required surgery24 The response to treatment was attributed to the polyp type. Translucent (immature, edematous) polyps, seen by videostroboscopy, were significantl y more likely to benefit from voca l therapy, when compared to fibrotic , hya line, or hemorrhagic (matu re) polyps24 In add ition, incomplete glotta l closure after voca l therapy was di scussed as a potential indication for surgica l referral. Without glotta l closure, ai r would sti ll escape during si ngi ng and phonation, resulting in persistently inefficient vocal use, sugge ting the need for aggressive treatment24 . ln this study, long­tem1 follow-up wa not performed, and there was no accounting for differences in methodology between voca l therapists. It was concluded that although not for everyone, there is a speci fi e patient populati on that would max imall y benefit from voca l therapy alone, while others should proceed directly to surgery24

No dul es , o r " si nger 's nodes" occ ur bilaterally a nd symmetrica lly on the voca l fo ld and are attributed primaril y to voca l abuse or misuse 11 ·25(Figure 3). Vocal fold nodules, similarly to polyps, are benign areas of edema and fibrosis25. It is worth noting that the difference between nodul es and polyps is not always evident, and there is a lack of clear hi stologica l distinction20 Vocal fold nodules present with hoarseness and breathiness due to a fa ilure of the vocal folds to approx imate, pitch breaks and fat igabi li ty25 . As detailed above, the fir t line treatment for voca l nodules is behaviourall y-ba ed vocal therapy3 An intervention review in 2009 found that there were no high quality randomized controll ed trial , which compared surgica l and non-surgica l interventions for vocal nodules26 The article reiterates the lack of definite hi tologic di stinction between nodules and polyps, as well as the lack of gold­standard assessment measures of voca l quality a barriers to performing adequate trials26 Other voca l fold pathology that is important to rul e out by an otolaryngologist, include laryngeal papi llomatos is, granulomas, dysplasia and carci noma, all of which have been documented in singers as causes for voice impairment.

CONCLUSIONS

Like many other occupational hea lth issues, dysphonia is associated with decreased quality of life, and may lead to loss of work in popul a ti o ns whose profess ions re ly o n vocal ab ility27

Otolaryngologists provide a major role in both surgical and non surgical correcti ons of nodules that are not amenable to con ervative, behavioural or voca l therapy treatments. Surgery was once beli eved to be profess ional sui cide for singers a decade ago 13, but thi s rapidly changing perspective reflects the advances in microsurgery that have created positive outcomes for appropriately selected patients22,24

Voice medicine reiterates the importance of multidisciplinary care and combined experti se that cater to the overall goals of a particular patient population . A always, health care profe sionals should be aware of these modalities that lie outside of tradi ti onal medicine.

REFERENCES

I. Sulica L. The Voice: Anatomy, Phy iology and Clinical Evaluation. Bailey B, John on J, eds., Otolaryngology - Head & Neck urgery, 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins 2006:817-827

2. Holmberg EB, Hillman RE, Hammarberg B, Sodersten M, ~· Efficacy of a behaviorally ba ed voice therapy protocol for vocal nodules. l..Yci.ce. 200 I Sep; 15(3):395-4 12.

3. van Gogh CD, Verdonck-de Leeuw IM, Boon-Kamma BA, Rinke! RN , de Bruin MD, Langendijk JA , Kuik DJ , Mahieu HF. The efficacy of voice therapy in patients after treatment for early glottic carcinoma. Cancer 2006 Jan I; I 06( I ):95-1 05

4 . .El.l.illt.N, Sundberg I, Grammin g P. What happen during vocal warm-up? l..Yci.ce. 1995 Mar;9( 1): 37-44.

UWOMJ I 80:2 I Fall 2011 25

5. Milbrath RL, olamon NP. Do vocal warm-up exercises alleviate vocal fatigue? J Speech Lang Hear Res. 2003 Apr;46(2):422-36.

6. Blaylock TR. Effects of systemati zed vocal warm-up on voices with di order of va rious et iologies. J Voice. 1999 Mar; 13( I ):43-50.

7. Habe oglu M. Habesoglu TE. Gunes P. Kini s V. Taros SZ. Eriman M. Egeli E. How does reflux affect laryngeal ti ssue quality? An experimental and histopathologic animal study. Otolaryngology - Head and Neck Surgery 20 I 0. 143(6):760-764

8. Johnston N, Bulmer D, Gill GA, Paneni M, Ross PE, Pear on JP, Pignatelli M, Axford SE, Dettmar PW, Kaufman JA. Cell biology of laryngeal epithelial defenses in health and disease: further studies. Ann Otol Rhino! Laryngo l. 2003 ; 11 2(6):48 1.

9. Franco, RA . Laryngopharyngeal reflux. Uptodate [online) Retrieved 30 June 20 11 from www uptodate com

10. Kaufman JA, Aviv JE, Casiano RR, haw GY. Laryngopharyngea l reflux: posi tion sta tement of the committee on peech, voice, and swallowi ng di orders of the American Academy of Otolaryngology - Head and Neck

urgery. Otolaryngol Head Neck urg 2002; 127.32 . II . Detecting the other reflux disease. Madani A, Wong E, Sowerby L, Fung

K, Gregor JC. J Fam Pract. 20 10 Feb;59(2) : 102-7. 12. Behlau M, Oliveira G. Vocal hygiene for the voice professional. Current

Opinion in Otolaryngology & Head and Neck urgery 2009, 17: 149- 154. 13. Sataloff RT. Arts medicine: an interdisciplinary paradigm. Ear, Nose, &

Throat Journal. 84(8):462-3, 2005 Aug. 14. Rosen CA, Anderson D, Murry T. Eva luating hoar eness : keeping your

patient 's voice healthy. Am Fam Phys ician 1998; 57:2775. 15. Johns MM . Update on the etiology, diagnosis, and treatment of vocal fold

nodules, polyps, and cysts. Curr Opin Otolaryngol Head eck Surg. 2003 Dec; II (6):456-6 1.

16. Haji T, Mori K, Omori K, lsshi ki . Experimental studies on the viscoelasticity of the vocal fold. Acta Otolaryngol. 1992; 11 2( I ) : 151-9.

17. Haji T, Mori K, Omori K, lsshiki N. Mechanical properties of the vocal fold. Stress-strain studies. Acta Otolaryngol. 1992; 112(3):559-65.

18. Tao C, Jiang JJ . Mechanical stress during phonation in a self-osci llating finite-element vocal fold model. J Biomech. 2007;40( I 0):219 1-8. Epub 2006 Dec 2 1.

19. Ti tze IR, Svec JG, Popolo PS. Vocal dose measures: quantifying accumulated vibration exposure in vocal fold ti ssues. J Speech Lang Hear Res. 2003 Aug;46(4):9 19-32 .

20. Cipriani NA, Martin DE, Corey JP, Portugal L, Caballero N, Lester R, Anthony B, Taxy JB. The Clinicopathologic Spectrum of Benign Mass Lesions of the Vocal Fold due to Vocal Abuse. tnt J Surg Pathol. 20 II Jun 16.

21. Kambic V, Radsel Z, Zargi M, Acko M. Vocal cord polyps: incidence, histology and pathogenesis. J Laryngol Otol. 1981 Jun ;95(6):609- 18.

22. Hochman II , Zeitels SM . Phonom icrosurgical management of vocal fold polyps: the subepithelia l microflap resection technique. J Voice. 2000 Mar;14(1): 112-8 .

23. Stajner-Katusic S, Horga D, Zrinski K V. A longitudinal study of voice before and after phonosurgery for removal of a polyp. Clin Lingui t Phon. 2008 Oct-Nov;22( I 0-11 ):857-63 .

24. Cohen SM, Garrett CG. Utility of voice therapy in the management of vocal fold polyps and cysts. Otolaryngol Head Neck Surg. 2007 May; 136(5):742-6.

25 . Lancer JM , Syder D, Jones AS, Le Boutillier A. Vocal cord nodules: a review. Clin Otolaryngol Allied Sci. 1988 Feb; 13( I ):43-5 1.

26. Pedersen M, McG lashan J. Cochrane Database Syst Rev. Surgical versus non-surgical interventions for vocal cord nodules. 200 I ;(2):CDOO 1934.

27. Ruotsalainen JH, Sell man J, Lehto L, et al. Interventi ons for preventing voice di sorders in adults. Cochrane Database Syst Rev 2007; 17:CD0063 72.

26 UWOMJ I 80:21 Fall2011

Transoral Robotic Surgery (TORS)

Jason Xu {Meds 2013), Michal Brichacek (Meds 2013)

Faculty Reviewer : Dr. Kevin Fung, Dr. Anthony Nichols

Minimally invas ive surgery has revo lutioni zed surgica l practice in the past two decades and is quickly becoming the tandard of care aero s multiple di sciplines. In head and

neck surgery, organ-preservation protoco ls and transora l laser microsurgery have laid the foundat ion for the recent development of transoral robotic surgery (TORS), which uses the da Vinci surgica l robot to orally approach the throat rather than traditi onal cerv ica l incisions into closed neck spaces. ! The technique was developed at the Univer ity of Pennsylvania, initiall y by demonstrating wide access to the laryngopharynx using mouth gag retractor and perfom1 ing procedures on a canine mode l. lin 2006, they descri bed its appl ication in human patients fo r resection of oropharyngea l squamous ce ll carcinoma (OPSCC).3The FDA approved the use of TORS in December of 2009 for resecti on of selected head and neck tumours.2

In December of 20 I 0, Dr. Kevin Fung and Dr. Anthony N ichols from the Department of Oto laryngo logy - Head and Neck Surgery at the University of Western Ontario (UWO) performed the first TORS procedure in Canada: a TORS upraglottic laryngectomy(Figure I ). Other options fo r the pati ent were e itheropen suprag lotti c laryngectomy with bilatera l neck dissecti ons or full course radiotherapy for 7 weeks (70 Gy) . With TORS, the patient was able to avoid temporary tracheotomy and nasogastric tube (NG) feeding, and with negative margins and nodes the patient completely avoidedpost­operati ve radiotherapy as we ii.Thi case hi ghlights some of the advantages of TORS fo r the treatment of head and neck cancer, which wi ll be discussed fu rther below along with detail s of the procedure and future directions.

SURGICAL PROCEDURE

The Da Vi nci surgical platfo rm consists of a conso le, a surgical cart, and a manipulator unit. The TORS procedure in vo lves the transoral inserti on of two wri sted instruments anns and a central 3D endoscope.4 The console offers the surgeon a three-dimensional magnifi ed view and allows control of the twoendowristed roboti c anns, whi ch helps to enhance manual dexterity.5 The system a ll ows for the surgeon's hand movements to be motion-sca led and thereby eliminates physiological hand tremor. 6

The first clinica l use of the Da Vinci robot fo r head and neck surgery involved the remova l of a benign oropharyngeal lesion and a thyroidectomy. 7 ,&Applications have expanded to procedures such as parathyroidectomy and skull ba ed surgery.9, I OHowever, the main application of TORS is in the treatment of malignancies caused by squamous cell carcinoma (SCC) which can invo lve the oral cav ity, oropharynx, hypopharynx, and larynx .6Such cases include TORS tonsillectomy, TORS tongue base resection, and TORS supraglotti c laryngectomy.

The primary adva ntages of roboti c surgery include the minimizati on of surgica l trauma, superior visuali zati on, improved precision, and the abili ty to recreate an open surgica l experi ence.6 Additional advantages include better safety and morbidi ty outcomes for the patient, which are di scussed below.Conver ely, there are certain di sadvantages ofTORS such as a confined operati ve fi e ld and fin ancial limitations such as the high initi al cost of the roboti c system (over a milli on dollars) and the high cost o f instruments (about one thousand doll ars per ca e) .l However, in centers where a robotic console a lready ex ists for general or urologic surgery, adding head and neck cases wi ll augment value of the machine and increase producti vity. I

Figure l. Dr. Anthony Nichols (left) and Dr. Kevin Fung (right) from the Department of Otolaryngo logy - Head and Neck Surgery at the Uni versity of Western Ontario,standing next to the control console of the Da Vinci surgica l robot.

OUTCOMES

Due to its relati ve in fa ncy, there are currently no contro ll ed studies comparing TORS procedures to their open surgical counterpart or primary chemoradiation for the treatment of oropharyngea l cancer. However, di ffe rent case series of patients who underwent resection of oropharyngeal squamous cell cancer (OPSCC) by TORS show promising re ults and highlight several advantages .

SAFETY

No major complicati ons and acute sequelae of TORS have been re ported . Mino r co mpli ca ti ons inc lude tran so ra l bleeding, exace rb a ti o n of s leep apnea fro m posto pera ti ve we lling , development of moderate tri smus, and temporary hypem asali ty of voice. lin general, patients who undergo TORS have lower estimated

UWOMJ I 80:2 I Fall 2011 27

blood loss (<200 mL) when compared to open surgery, and none have required blood transfusions. ! TORS patients a lso have a shorter ho pita! length of stay, as most are di scharged six days after OP CC re sec tion .3 ,4ln co ntras t , patient after ope n s uprag lottic laryngectomy wou ld typically stay I 0-14 day in ho pita! post­operatively.

ONCOLOGICAL

OP CC re ection with negati ve margins in a ll patients was reported by different ca e series ranging from 12 to 45 patients.4, II , 14- 16 For example, in the case series from the Mayo c linic, a ll 45 patients with ei ther ba e of tongue or tonsillar fo a tumors had negative margi ns after TORS resection, and 12 were able to avoid adjuvant radi ation . II A recent publication from the Univer ity of Pennsylvania reports that, out of 50 cases, 2 patients developed distant metasta es and one patient developed both loca l and di stant recurrence of di ease following TORS resection of OPS (mean follow-up : 2 years). 19More long-term onco logical outcomes are unavailable at thi s time.

FUNCTIONAL

Pre erving airway and swa llowing functi on is an important determinant of quality of life followin g oropharyngeal surgery, and large ly depends on whether the patient receive po !-operati ve radiation or chemotherapy. To date, none of the four patient treated with TORS at UWO have required adjuvant radiation therapy a they al l had negati ve margin and nodes po t-surgery (negative nodes weredetermined by pathological staging of a taged neck di section two weeks post-TORS). In the event that patients do have positi ve node , the adj uvant rad iation do age needed (60Gy) will be smaller than primary radiation treatment (70-72Gy), minimizing s ide effects.

At other centers, reported rates of temporary tracheotomy in patients who undergo TOR range from 3% to 31 %, with an average time to decannulation of even days.4, II , 15The use of Gtube for enteral feeding shows greater variance due to surgeon and center preference. In a case series of 45 patients at the Mayo clini c,

Gtubes were used in 48% of patients, with a mean durat ion of 12.5 day .4 In another case erie of 18 patients at the Mount S inai choo l of Medicine, no feedingtubes were used and patients were fed a pureed diet one day after urgery. I4These data suggest an advantage over primary chemoradiat ion , w here 17-30% pati e nts a re gastrostomy-tube dependent after one year due to dysphagia 18, and open surgery, where all patients are typ ica lly kept on NG tube for several weeks due to a pi ration ri k.

FUTURE DIRECTION

With the increasing popularity of robotic surgery, training guideline and opportunities mu t be developed for current practitioner looking for certifi cation . Similarly, a more re idency programs acquire robot access, standardization of res idency and fe ll ow hip curri culum w ill a lso be important. Currently, a ll Head and Neck Surgery fellows graduating from the Un iver ity of Penn ylvania are trained in TOR . I The university a lso runs a TORS tra ining program for surgeon from around the world .

As surgeons become more comfortable with TORS, new and innovati ve procedures are being deve loped as well. One exampl e is transax i ll ary thyroidectomy, where the thyroid gland i removed without having to create an unaesthetic cervica l scar. The procedure was developed in Korea and has been performed in over 300 patients a of2009.17

CONCLUSIONS

TORS is a safe and minima ll y invasive surgical techniquewith many applications in head and neck urgery. Benefits of TORS over tradi tional open surgery include hand tremor reduction , better visualiza tion , and minimization of surgica l trauma. Promis ing data

from case series uggest possible benefit of TORS over primary chemoradiation at preservation of wallowing function after resection of oropharyngea l tumours. This offersa very ad_vantageous quality of life consideration, especially for the increasmg mctdence ofOPSC~m young HPV-posi ti ve patients. l9 However, long-ter_m oncologtcal outcomes of oropharyngeal cancer afterTORS resection are not yet ava ilable, and further tudies are warranted .

REFERENCES

1. Weinstein GS, O ' Ma lletJr BW, De ai SC, Quon H. Transoral robotic urge ry: does the ends justify the means? Current Opinion in

Otolaryngology & Head and eck Surgery 2009; 17:126-13 1. 2. Uni versity of Penn ylvania School of Medicine. "FDA c lear TransOral

robotic surgery." c ienceDaily [updated 6 January 20 I 0; cited 15 March 20 11) . Available from : http "// www sciencedaily com / rel eases/ 20 10/01 / 100 104 114553 .htm

3. O'Malley BW Jr, Wei n tein G , nyder W, Hockstein G. Transoral roboti c surgery (TOR ) for base of tongue neoplasms. Laryngoscope 2006; 116:1465-1472 .

4. Moore EJ , Olsen KD, Kasperbauer JL. Transora l robotic urgery for oropharyngeal quamou ce ll carcinoma: a prospective tudy of feasibility and functional outcomes. Laryngo cope 2009; 199( I ):2 156-64.

5. Moorthy K. Munz Y, Dosis J. Hernandez J, Martin S, Bello F, et al. Dexteri ty enhancement' ith robotic surgery. urgEndo c 2004 ; 18:790-5 .

6. Arora A, et a l. , linica l appl ication of Telerobotic E T-Head and Neck surgery. International Journal of Surgery 20 II ; 1-8.

7. McLeod IK, Melder P . Da Vinci robot-as isted exci ion of a va llecular cy t: a case report . ar o e Throat J 2005; 4: 170-2. Lobe TE, Wright K, Irish M . ovel uses of surgica l robotics in head and neck su.rgery. J Laparoendo c dv urg Tech A 2005; 15(6):647-52.

9. Profanter C. Schmid T, Prommegger R. Bale R, Sauper T, Bodner J . Robot-assi ted media tinalparath yro idectomy. SurgEndosc 2004; 18(5): 6 -70.

I 0. O ' Malley Jr BW, We in tein G . Robotic skull ba e surgery: preclinical inve ti gations to human clinical app lica tion. A.rch Otolayngol Head eck

urg 2007; 133 :1215-9. II . I e li T, Kulber h B, I eli . Carroll W. Rosenthal E, con Magnuson J.

Functional outcome after rransora l robotic surgery for head and neck cancer. Otolaryngol Head eck Surg 2009; 141 : 166-7 1.

12. Ikeda Y, Takami H. a aki Y, Takayama J, Niimi M, Kan . omparative tudy of thyroidectomies: endoscopic surgery versus conventional open

surgery. SurgEndosc 2002; 16: 1741-5. 13. Bhayani MK, Hoi inger F , Lai Y. A hifting paradigm for patients with

head and neck cancer: tran ora l robo ti c surgery (TOR ). Oncology (Willi ston Park ) 20 10 Oct :24( II ): I 0 I 0- 1015.

14. Genden EM, Desai ung C K. Transoral roboti c surgery for the management of head and neck cancer: a preliminary ex perience. Head

eck 2009 Mar;3 1 (3):2 3-289. 15. Boudreaux B . Rosentha l L, Magnu on J , ewman J R, Desmond RA,

C lemons L, et al. Robot-assisted surgery for upper aerodigesti e tract ncopla ms. Arch Ot laryngol Head eck urg 2009 Apr; 135(4):397-40 1.

16. Weinstein G . O'Malley BW,Jr, nyder W, hern1an E, Quon H. Transoral ro boti c surgery: radica l tonsillectomy. Arch Otolary11gol Head eck Surg 2007 Dec; 133( 12): 1220- 1226.

17. Kang SW, Lee , Lee SH, Lee KY, Jeong JJ , Lee Y , am KH , hang H , Chung WY, Park . Robotic thyroid surgery u ing a gas les , tran ax illary approach and the daVinci system : the operative outcomes of 338 consecutive patients. urgery. 2009; 146(6): 104 -55.

18. Nguyen . P, Moltz , Frank , e t a l. Dysphagia followin g chemoradJatJon for loca ll y advanced head and neck cancer. Ann Oncol 2004; 15:383- 388.

19. ohen MA, Weinstein G , O'Malley BW, Jr. , Feldman M, Quon H. Transoral robot1 c urgery and human papillomavirus tatu : Oncologic re ults. Head eck. 20 11 Apr;33(4) :573-80.

28 UWOMJ I 80 :21 Fall2011

The role of FOG-PET and PET/CT in the diagnosis and staging of head and neck cancer

Adrian Matthews (Meds 2013), Jai Prashanth Jayakar (Meds 2013) and Joshua Rosenblat (Meds 2014)

Faculty Reviewer : Dr. John Yoo, Department of Otolaryngology - Head and Neck Su rgery

An estimated 644,000 cases of head and neck cancer are di agnosed worldwide each yea r, w ith head and neck squamous cell carcinoma (HNSCC) accounting fo r over 90%

of these. Common presenting s ites inc lude the ora l cav ity, oropharynx, nasopharynx, hypopharynx , and larynx. I While chronic tobacco use and alcohol consumption are well -establi shed ri sk factors,2 human papillomavirus (HPV) infection of the upper aerodigestive tract has been cau a lly li nked to tumorigenesis.3 In particular, the increasing rates of oropharyngea l cancers, especially young non-smokers, has been directly attributed to HPV infect ion.

The diagnostic workup of HNSCC typically incl udes history and physical examination, endoscopic-guided biopsy and high­reso lution contras t-enh anced computed tomograph y (CT) o r magnetic resonance imaging (MRI). Whil e CT and MRI have traditionally been the cornerstones of the imaging workup, 2-fluoro­[ 18F]-deoxy-2-D-glucose positron emission tomography (FDG- PET) plays an increasing role in the diagnosis, raging and fo llow-up of HNSCC patients.! ,4,5

FDG-PET AND PET/CT IMAGING

FOG, a glucose ana log labe ll ed with the radi onuclide 18F, preferentially accumu lates in cell s that have an increased g lyco lytic rate - a characteri stic fea ture of cancer cell s.6 FDG-PET is thus a fu nctional imaging modality that detects cellular metabol ic changes, unlike CT and MRI , which re ly on structura l abnormali tie . The positrons emitted by the radi onuclide annihilate nearby electrons and create photons that are captured by an array of detectors and reconstructed into a 3D image. A lthough PET a lone is limited by its lack of anatomic localizati on, the advent of the hybrid PET/CT scanner has overcome thi s by fu sing PET and CT images acqu ired in a single session, permitting deta iled visualizati on of both structural and functional aspects of di sease. I ,4-6

STAGING OF HEAD AND NECK CANCER

TNMSTAGING

HNSCC is staged according to the size and extent of the pri mary tumour (T), regional lymph node involvement (N) and the presence of distant metastases (M).4 Accurate staging at the time of di agnosis is the most important factor for planning manage ment and determining prognosis.4,7 Since the preservation or restorat ion of function is a top priori ty in the management of patients with HNSCC, fu ncti on-sparing strategies such as minimally invasive surgery or (chemo)radiotherapy are often considered as fi rst- line treatments .& Thorough clinica l assessment, including imaging, is vita l to optimal staging of HNSCC. Furthermore, re-evaluation of patients fo llowing treatment may be especiall y challenging in HNSCC, due to difficul ty in obtaining pathology. The fo ll owing subsecti ons review the c li nica l indications for FOG-PET and PET/CT in staging HNSCC.

PRJ MA RY TUMOUR

Whil e PET and PET/CT have been shown to be at least as effecti ve as CT or MRI at detecting primary tu mours, these modali ties are not used in tandard practice to T- tage newly di agnosed HNSCC because their anatomic reso lution is not as hi gh as that of MRl or contrast-enhanced multi slice CT.9- I 3 An early tumour may have poor FOG uptake and its detection on the scan may be obscured by cross contamination of physiologic acti vity from surrounding ti ssues - the so-ca ll ed 'spillover effect' . l4 CT and MRI are usefu l fo r initia l T-staging, since the ir high spat ial resolution and soft-tissue contrast can demonstrate subtle abnormaliti es and accurate ly delineate tumour volume.

CARCINO MA OF UNKNOWN PRIMARY

In 2-9% of patients with newly di agnosed HNSCC, cervica l node metastases are clinically ev ident at biopsy but the primary tumour cannot be identified by conventi ona l workup, which includes physica l examination, CT, MRI and endoscopic-guided biopsy. l 5 PET/CT has proven to be sign ifi cantly more sensitive than CT (94 .0 versus 7 1.6%, respectively, P < 0.00 I) at detecting carcinomas of unknown primary. l 6 Rusthoven et al. reviewed 16 studi es published between I 994 and 2003 and found that among 302 patients with a negati ve conventional workup, FOG-PET detected the primary tumour in 74 patients (24.5%).17 In a more recent review, Al­lbraheem et al. performed a meta-analys is of 8 stud ies publi shed between 2000 and 2009.5 FOG-P ET or PET/CT were able to detect the unknown primary in 5 I of 180 patients wi th an otherwise inconclu ive workup . Delineation of a pri mary tumour i e sential fo r delivering targeted therapy, minimizing therapeutic morbidi ty caused by wide- fi eld irradiation and improving prognosis. IS A recent report noted that findin gs made by FOG- PET changed therapeuti c management in 25% of pati ents. l9 In light of th is evidence, PET/CT may have an important ro le in the di agnosti c assessment of carcinoma of unknown primary.5

CERVICAL NO DE METASTASES

Cervica l node status is the most important prognosti c factor in HNSCC.7 Cure rate declines by nearly 50% when cervical metastase are present.20 Metastatic lymph nodes are found in approximately half of patients at the time of di agnos is.2 1 PET/CT has been shown to have better sensiti vity and specificity for pathologic cerv ica l nodes than MRI and CT, likely because the latter rely on nodal size and contrast-enhancement criteri a which are not specific and can miss metastase in normall y sized nodes .22 ,23 Nevertheless, CT is generally used for loca l staging of clinically mani fes t cerv ica l nodes at initial di agnosis, due to its c linical ava ilabili ty and accurate T-staging of the primary tumour.

UWOMJ I 80 :2 I Fall 201 1 29

CLINICALLY NEGATIVE (NO) NECKS

l f clinica l examination fa ils to identi fy metastati c cervica l lymph nodes in patients with primary HNSCC, these patients are sa id to have a clinica lly negati ve (NO) neck. Since the probabili ty that these patients actuall y have a pathologica l neck varies between I 0-45%, elective neck di ssection is recommended in cases where the ri sk of occult cervical mets is greater than 20%.4 While PET/CT is the most accurate imaging modality for detecting occult metastases, the role o f PET/CT in the asse sment of NO necks is st ill controversia l. ? Microscopic di sease or nodal metastases located adjacent to the primary tumour may evade radiographic detection and contribute to fa lse-negatives. Two studi es reported sensitivity and specifi city ranging from 67-79% and 82-95%, respecti vely, leading the authors to conclude that PET/CT is not yet accurate enough to inform the need for surgical di ssecti on in cases of occult nodal disease.24,25

SECOND PRIMARY (SYNCHRONOUS) MALIGNANCY AND DISTANT METASTASES

Pati ents with advanced HNSCC are at higher ri sk for deve loping distant metastases and for presenting with a second primary (synchronous) tumour;26 the latter being defin ed a a hi sto logica lly dist inct malignancy, separated from the primary tumour by at least 2cm of normal muco a.27 The cost of mi ssing distant metastases or synchronous tumours at the time of initial diagnosis is high. Curati ve therapies a re ofte n assoc iated w ith s ig nifi ca nt mo rbidity, necessitati ng the careful se lection of patients with nonmetastatic di sease who may benefit from the treatment and not eventually succu mb to previously undetected di stant di sease .28 Aggressive subtypes, such as nasopharyngea l carcinoma, have a tendency to metastas ize to the lungs, li ver and bone; hence, the conventional imaging workup fo r di stant metastases is comprised of chest radi ography, abdominal ultrasound, and skeletal scintigraphy (bone scan). Several reports have assessed the efficacy of PET/CT in staging di stant metastases and synchronous tumours and found that it is the most sensiti ve, spec ific and accurate modali ty and may replace conventional techniques. l4,28,29 A multicentre prospecti ve study of 92 patients found that PET/CT had a higher ensiti vity (63%) than chest CT (37%), due to its abili ty to image the whole body with a single scan and detect di stant hypermetaboli c foc i.30 PET/CT can therefore be considered as the moda lity of choice for the diagnostic workup of di stant metastases and synchronous tumours. 7

RESIDUAL AND RECURRENT DISEASE

The reliance o f CT and MRl on morpho logic criteri a often makes the detection of post-treatment residual tumour acti vity or recurrent disease diffi cult, s ince the regiona l head and neck anatomy may be di storted a fter therapeuti c (chemo)radiotherapy and/or urgery.4 Al­lbraheem et a l. rev iewed the utili ty o f PET and PET/CT for

identi fy ing disease recurrence in head and neck cancers.5 Among 7 studies published between 2004 and 2009, PET or PET/CT demonstrated hi gh sensiti v ity (83 -1 00%) and relatively h1gh specificity (78-98%) and accuracy (~1-90%~, oft~n significantly outperforming CT and MRI. InflammatiOn and mfe~t10n are common treatment sequelae that may increase FDG uptake_ m certam . tissues; hence the addition of CT to PET is espec1ally Important m these situat{ons in order to distingui sh truly patholog ic areas from post­irradi ated ti ssue. l2 ,22 The anatomica l landmarks provided by CT have been s how n to dec rease the number of equivocal hypermetabo lic foci and there fore reduce the amo~nt non-invasive imaging and invasive biopsies required for d1agnosts of recurrence.

12

LIMITATIONS

F a/se-positives

In addition to the post-irradiati on changes di scussed above, increased FDG uptake may occur in benign hyperplastic conditions such as thyroid or pleomorph ic adenomas . Regiona l physiologic FDG uptake in lympho id ti ssue, a li vary g lands, strained or excessively used skeleta l muscles and activated brown fa t ti ssue may a lso confound interpretation and be erroneously attributed to malignancy.4,6 It is recom mended that posi ti ve results be conflfllled by biopsy.6

False-negatives

Since the patial resolution of FDG-PET is limited to 4-1 Omm, it abili ty to precisely loca li ze sma ll tumours or microscopic tissue involvement is often dimini hed in the head and neck region. Tumours with low metabolic rate and poor avidity for FDG uptake may also be difficult to characterize on PET scans.6

SUMMARY AND RECOMMENDATIONS

In 2009 , Yoo and Walker-Dilks reviewed the data and made recommendations for the use of FDG-PET in head and neck cancer. 3 1 The gu idelines, part of an initiative of the Program in Evidence­Based Care for Cancer Care Ontario, are consistent with the findings reviewed here and are summarized in Table I . It is worthwhi le to note that studies examining PET and PET/CT were not distinguished in the report ; however, the hybrid system clearly confers a diagnosti c advantage over ei ther modali ty alone.4-7 De pite its limitations, increa ing use of PET/CT for the diagnosis, stag ing and follow-up of HNSCC pat ients ha provided physicians with a powerful tool that will continue to improve patient outcomes as the technology advances and clinica l guideline are re fined .

REFERENCES

I. Marur • Forasti ere AA . Head and Neck Cancer: Changing Epidemiology, Diagnosis, and Treatment. Mayo Clin Proc 2008;83(4):489-50 I.

Table 1. Recommendations for FOG-PET in head and neck cancer. Adapted from Yoo and Walker-Dilks3 1

FOG-PET and PET/CT are recommended for :

Diagnosis/Staging

• • •

M and bil ~te ra l nodal staging of advanced HNSCC di splaying equivocal conventional imaging Identifi catiOn of unknown pnm_ary Site, m additi on to conventional imaging and diagnostic panendoscopy stagmg of nasopharyngea l carc moma without ev1dence of distant di sease

Recurrence/Restaging

• restaging patients who are being considered for major salvage treatment (surgery or other)

30 UWOMJ I 80:2 I Fall 2011

2. Goldenberg D, Lee J, Koch WM , et al. Habitual ri sk factor for head and neck cancer. Otolaryngol Head Neck Surg 2004; 131:986-93.

3. Gi llison ML, Koch WM, Capone RB, et al. Ev idence for a Causa l Association Between Human Papillomav iru and a Subset of Head and Neck Cancers. J Nat! Cancer Lnst 2000;92:709-20.

4. Gordin A, Daitzchman M, Israel 0. Hybrid Imaging of Head and Neck Malignancies. In: Delbeke D, Israel 0 , editors. Hybrid PET/CT and SPECT/CT Imaging. New York : Springer; 20 I 0. p. 137- 17 1.

5. AI-Lbraheem A, Buck A, Krause BJ , et al. Clini cal Applicat ions of FDG PET and PET/CT in Head and Neck Cancer. J Oncol 2009;2009:208725.

6. Fletcher JW, Djulbegovic B, Soares HP, et al. Recommendations on the Use of 18F-F DG PET in Oncology. J Nucl Med 2008;49:480-508.

7. de Bree R, Castelijns JA, Hoekstra OS, et al. Advances in imaging in the work-up of head and neck cancer patients. Oral Oncol 2009;45:930-35 .

8. O'Sullivan B, Shah J. New TNM Staging Criteria for Head and Neck Tumors. Semin Surg Oncol 2003;2 1 :30-42 .

9. Roh JL, Yeo NK, Kim JS. Utility of 2- [ 18F] fluoro-2-deoxy-d-glucose posi tron emission tomography and positron emission tomography/ computed tomography imaging in the preoperati ve staging of head and neck squamous cell carcinoma. Oral Oncol 2007;43(9):887-93.

10. Ng SH, Yen TC, Liao CT, et al. 18F-FDG PET and CT/M RI in oral cavi ty squamous cell carcinoma : a pro pective study of 124 patients with histologic correlation. J Nucl Med 2005;46(7): 1136-43.

II. Gordin A, Daitzchman M, Doweck I, et al. Fluorodeoxyglucose-positron emission tomography/computed tomography imaging in patients with carcinoma of the larynx: diagnostic accuracy and impact on clinical management. Laryngoscope 2006; 11 6(2):273-78.

12.Schoder H, Yeung HW, Gonen M, et al. Head and neck cancer: clinical usefulness and accuracy of PET/CT image fusion . Radiology 2004;23 1 ( I): 65-72.

13. Ha PK, Hdeib A, Goldenberg D. The role of positron emission tomography and computed tomography fusion in the management of early-stage and advanced-stage primary head and neck squamous cell carcinoma. Arch Otolaryngol 2006; 132( I) 12-1 6.

14. Ng SH, Chan SC, Yen TC. Staging of untreated nasopharyngea l carcinoma with PET/CT: comparison with conventional imaging work-up. Eur J Nucl Med Mol Imaging 2009;36: 12-22.

15. Jereczek-Fossa BA, Jassem J, Orecchi a R. Cervica l lymph node metastases of squamous ce ll carcinoma from an unknown primary. Cancer Treat Rev 2004;30: 153-64.

16.Roh JL, Kim JS , Lee JH , et a l. Utility of co mbin ed 18F­fluorodeoxyglucose-positron emiss ion tomography and computed tomography in pat ients with cervical metastases from unknown primary tumors. Oral Oncol 2009;45(3):2 18-24.

17. Rusthoven KE, Koshy M, Pau lino AC. The role of fluorodeoxyglucose positron emission tomography in cervical lymph nodes metastases from unknown primary tumour. Cancer 2004; I 0 I :2642-49.

18. Schmalbach C, Miller F. Occu lt primary head and neck carcinoma. Curr Oncol Rep 2007;9(2): 139-46.

19. Johansen J, Buus S, Loft A, et al. Prospective study of 18FDG-PET in the detection and management of patient with lymph node metasta es to the neck from an unknown primary tumor. Results from the DAHANCA- 13 sutdy. Head Neck 2008;30( 4 ):4 71-78.

20. Shah J. Cervical lymph node metastases: diagnostic, therapeuti c and prognostic implications. Oncology 1990;4 :6 1-69.

21. Dammann F, Horger M, Mueller-Berg M, et al. Rational diagnosis of squamous cell carcinoma of the head and neck region : comparati ve evaluation of CT, MRJ, and 18FDG PET. Am J Roentgenol 2005; 184(4): 1326-31.

22. Gordin A, Golz A, Daitzchman M, et al. Fluorine- IS flu orodeoxyglucose positron emission tomography/computed tomography imaging in pat ient with carcinoma of the nasopharynx: diagnostic accuracy and impact on clinical management. Int J Radi at Oncol Bioi Phys 2007;68(2):370-6.

23. Quon A, Fischbei n NJ, McDougall IR, et al. Clinical role of 18F-FDG PET/CT in the management of squamous ce ll carcinoma of the head and neck and thyroid carcinoma. J Nucl Med 2007;48 Suppl I :58S-67S.

24. Nahmias C, Carl son ER, Duncan LD, et al. Pos itron emi ss ion tomograp hy/compu terized tomography (PET/CT) sca nnin g for preoperative staging of patients with oraVhead and neck cancer. J Oral Maxi llofac Surg 2007;65( 12):2524-35 .

25. Schoder H, Carlson DL, Kraus DH, et al. 18F-FDG PET/CT for detecting nodal metastases in patients with oral cancer staged NO by clinical examination and CTIMRJ. J Nucl Med 2006;47(5) :755-62.

26. Teknos TN, Rosenthal EL, Lee D, et al. Positron emi ssion tomography in the evaluati on of stage Ill and IV head and neck cancer. Head Neck 200 I ;23( 12): I 056-60.

27. Vaamonde P, Martin C, del Rio M, et al. Second primary ma lignancies in patients with cancer of the head and neck. Otolaryngol Head Neck Surg 2003 ; 129( I ):65-70.

28. Chua ML, Ong SC, Wee JT, et al. Comparison of 4 modalities for distant metastasis staging in endemic nasopharyngeal carcinoma. Head Neck 2009;3 1 (3):346-54.

29. Liu FY, Lin CY, Chang JT. 18F-FDG PET can replace conventional work­up in primary M staging of nonkeratinizi ng nasopharyngeal carci noma. J Nucl Med 2007;48( 10):1614-9.

30. Senft A, de Bree R, Hoekstra OS, et al. Screening for distant metastases in head and neck cancer patient by chest CT or whole body FDG-PET: a prospective multicenter trial. Radiother Oncol 2008;87(2):22 1-9.

31. Yoo J, Walker-Di lks C. PET imaging in head and neck cancer: recommendation . Toronto (ON): Cancer Care Ontario (CCO); 2009 Jan 19. 43p. (Recommendation report - PET; no. 2).

UWOMJ I 80 :2 I Fall 2011 31

Marijuana use: sequelae and implications for health promotion

Karl ine Treurnicht Naylor (Meds 2013), Daniel James (Meds 2013) and Stephanie Gottheil (Meds 2014)

Faculty Reviewer : Dr. Donald Farquhar

A s of 2003 , 40% of American aged 12 yea r and older had smoked marijuana at least once. 1 Approximately 30% of Canadian youths from Grades 7-1 2 have tried cannabi s at

least once.2 Marijuana is the most widely-used illic it substance in Canada, with l 0.6% of the Canadian popu lation reporting u e in 2009.3 Thi s is si milar to the US annual fi gure of9%.4 Global reports indicate that the average age o f first marijuana use is decreas ing, even as the average delta-9-tetrahydrocannabinol (THC) content of cannabi s is on the rise. This may lead to an increase in both addicti ve potential and adverse effects of marijuana use. 5

A survey of the adult US population comparing fi gures from 1992 and 2002 suggested that the prevalence of marijuana use remained stable over the decade, but the prevalence o f marijuana dependence increased significantly. Thi s increase in marijuana use disorders has occurred in the absence o f increased frequency or quantity of marij uana use, suggesting that the enhanced potency of THC may have lead to the rise in rates 6 Treatment admi ssions for cannabi s abuse have ri sen steadily over the past ten years, including a 2-fold increase in the US and 3-fold increases in Australia and Europe.7

Although publi c perception remains that cannabi is "softer" and less dangerous than other illi cit substances, cannabis use is becoming a major publi c hea lth concern ; some research even sugge ts it may serve as a gateway drug to "harder" substances.s Furthermore, mul tipl e studies have shown an increa ed ri sk in marij uana users of other long-tenn hea lth consequences . In thi s paper, we review current research and understandipg of marijuana's impact on hea lth outcomes. We also prov ide an overview of at-ri sk popu lati ons for use and abuse of marij uana, summarize marijuana' potenti al positi ve e ffects, and di scuss implications for hea lth promoti on and various levels of preventi on.

PULMONARY EFFECTS

Numerou s studies have shown that the combustion of tobacco and marijuana produces s imil ar hannful compound .s,9 The ri sks of marijuana may be increased by three factors. Marijuana smoke has three times more tar and 1.5 times more carcinogeni c substances than tobacco smoke.10 Marijuana smoke is typica ll y inhaled more deeply and held in the lungs longer: there is more time for depos ition of parti culate matter. Furthermore, marijuana cigarettes do not conta in the same filter apparatus as conventi onal tobacco cigarettes. On the other hand, even heavy marijuana use invo lves far le s smoke inhalation than the equiva lent amount o f tobacco in a pack-a-day smoker. One analy is of 19 previous studies defined marijuana use as smoking I 0 or more marijuana cigarettes per week for 5 or more years.1 One pack o f tobacco cigarettes contains 20-25 cigarettes, and the cigarettes generally contain more combustib le materi al than their marijuana counterparts.

Smoke - whether from marijuana, tobacco or any other combustible ­is noxious to the airways. Thi s stimulates short-term bronchitic reacti ons, including coughing, sputum production and wheezing. In tum, these activate the mucocili ary esca lato r, whi ch carries parti culate matter from the bronchi cranially to be expectorated or swall owed.

One systemati c rev iew found that inhaling marijuana smoke can cause clini cal dyspnea and pharyng iti , as we ll as exacerbating pre­ex isting pulmonary illnesses such as asthma and cysti c fibrosis; these effects persi ted after adju ting fo r concurrent tobacco use. 5 Despite these apparently harmfu l effects, the review fo und no a sociation between marijuana smoke inhalation and effects on FEY I (forced !­second expiratory vo lume) or FVC (forced vital capacity), DLco (diffusi ng capacity of the lung of carbon monox ide) or airway hyperreacti vity. The authors explained these findings by sugge ting that cannabinoid promote the Th-2 anti- infl ammatory immune response while nicotine suppres es it. One study noted that the use of a vapourizer when consuming marij uana was associated with decreased respiratory sym ptom . 11 A vapourizer is a device that heats the marijuana to the vaporiza ti on point of the cannabinoids without the use of flame, thereby obv iat ing the consequences of smoke inhalation. Although there are many confounders in these analy es, not the least of which is the fac t that many marijuana users cut the dried marijuana with commercially-ava ilable tobacco, it can be concluded that smok ing marijuana exacerbates pre-ex i ting respirato ry co mpl a ints by directl y irritating th e respiratory epithe lium . However, contrary to tobacco moke, marijuana smoke does not seem to cause ob tructive pulmonary di seases.

LUNG CANCER

The _extant_ litera ll.~ re on marijuana and lung cancer presents confl1ctmg mfo rmatlon. On the one hand, marijuana smoke contain benzopyrene, a carcinogenic hydrocarbon also found in tobacco smoke, which has been _implicated in mutations related to lung cancer. Ex penmenta l tud1es have also demonstrated THC-induced ma lignant cell pro life rati on and suggested that THC inhibits antitumour immunity, thu s promoting tumor growth. In contrast, other v1tro m~de l s suggest that cannabinoid may actua lly exhibit ant1carcmogen1 c effects. 12 In an attempt to reconc ile these di veraent streams o f thought, Mehra, Moore, Crothers et al. undertook a systematic review to detennine the associations between marijuana mokmg

1 and lung cancer incidence, -~i sk factor , or premalignant

changes. The author found that manJuana smoking bas increased tar de_hve~ ~o lungs compared with cigarettes, and marijuana smoke contams s1mdar carc inogen as tobacco smoke, o ften in increased

32 UWOMJ I 80 :21 Fall2011

concentrations. Marijuana smoking was associated with the presence of more metaplastic cells, impai red alveo lar macrophage function , and increased oxidative stress when compared with non-smokers. Six studies included in the systematic review reported hi stopathologic and molecular findin gs from bronchi al biopsy; in a ll studies, marijuana smokin g was a soc ia ted with a bn o rm a l a nd/o r precancerous alterations when compared with e ither non-smoker or tobacco smokers. One study in particular reported an additi ve effect between marijuana and tobacco use. All the e findings suggest a biological plausibility for the association between marijuana use and lung carcinogenes is. However, a cohort study of 65,000 subj ects showed no increase in lung cancer incidence in marijuana smoker after contro lling for tobacco use. The authors suggested that there may be methodological concerns underpinning the lack of empiri ca l support fo r increased lung cancer incidence in marijuana users, including the need for more detailed assessment of marijuana exposure and longer follow-up periods. They a lso cautioned that physicians should still advise their patients of the potentia l adver e health effects of marijuana use, including premali gnant lung changes . I

While methodological factor may we ll account for the lack of evidence for an association between lung cancer and marijuana use, Melamede 13 ha summarized another line of thought: although marijuana and tobacco smoke contain s imilar carc inogen , cannabi noids and nicotine present with very different cellular effects. Firstly, although low-doses of THC may indeed promote tumour growth, the response appears to be biphasic; a lternate doses of cannabinoid have been capable of destroying cancer cells (including lung, breast, prostate, skin, and g lioma) in vitro and in animal models. Secondly, both nicotine and cannabinoid receptors are linked to signaling pathways that can tum on anti-apoptosis (i.e. preventing cell death). Nicotine receptor are found in respiratory epithe li al cells, whi le cannabinoid receptors are not. As such, when nicoti ne receptors are st imulated in respiratory cell s, there is an anti-apoptotic signal; the prevention of cell death under exposure to such mutagenic conditions (i.e. smoking) is likely to amplify carcinogenic potenti al. Thirdly, while nicotine promotes neovascul arizat ion and thus tumour growth, cannabinoids inhibits angiogenesis and results in tumour regression. Finally, the introduction of particulate matter and carcinogens into the respiratory system results in the creation of a pro-inflammatory state . In this ci rcumstance, cannabinoids reduce the associated free radical production by dri ving a re lative ly anti ­inflammatory Th2 immune cytokine profile. Melamede suggests that all these critica l factors can ex plai n the lack of association between cannabis use and lung cancer.13

Even in light of this controversy surrounding cannabinoids and their association with lung carcinogenesis, Guzman has gone so far as to suggest that cannabinoids could be used to deve lop novel anticancer therapies.14 In additi on to evidence uggesting inhibition of tumour growth, marijuana may a lso be beneficial to chemotherapy patients- it has the potentia l to miti gate nausea, vom iting, and pa in while also stimulating appeti te.

NEUROPSYCHOLOGICAL EFFECTS

Aside from its respiratory and pulmonary effects, marijuana use has been associated with neuropsychologica l consequences. Chroni c marijuana use has hi storica lly been associated with impaired cognition, including reduced attention, memory, higher cogniti ve function (e.g. executi ve function) and psychomotor defi cits. One study showed that after 25 days of abstinence, moderate (8-35 marijuana cigarettes/week) and heavy (53-84 marijuana cigarettes/ week) users had decreased activity in the ri ght latera l orbitofrontal cortex and the right dorsolateral prefrontal cortex, and increased activity in the left cerebellum, compared to the contro l group, during a decision-making game.15 Another imaging study, using transcranial

Doppler sonography, showed increased cerebrovascu lar resi tance in chroni c li ght to heavy users.16 However, these studies were small , with II and 54 subjects, respectively. One meta-analysis of tudies tota lling 623 chron ic marijuana users fo und that a lthough these indi viduals may show decreased ab ili ty to learn and remember new inforn1ati on in the long tern1, other cogniti ve proces es were unaffected. Thus, while there may be neurophysiological and neurovascul ar effects of chronic marijuana use, some of these effects may be sil ent.

Marijuana use has been shown to have negative psychological consequences, specifica ll y an increased ri sk of psychosi . It is poss ible that cannabinoids ' effects on dopam ine release contribute to the onset of psychosis.17 A ystematic rev iew of 35 popu lat ion-based longitudinal stud ies concluded that individuals who had ever used marijuana had an increased risk of developing p ychosis later in life . 18 Furthermore, a dose-dependent relationship was observed where heavier users had a further increased ri sk of psychosis (adj usted OR 1.41 , 95% CI 1.20- 1.65 vs. 2.09, 1.54-2.84, respectively) . Of course, a possible interpretat ion of these re ults is that an underlying, undi agnosed psychotic disorder leads to cannabis u e, which faci litates the di scovery of the pre-exi ting psychological illness.

Similarl y, the oft-c ited 'amot iva tional syndrome,' in which the sufferer is chronica lly unproducti ve, a imless and unmoti vated, is assoc iated with chronic marijuana use. One study found that indi viduals who have used marijuana a minimum of 5000 times were signifi cantly less likely to graduate from co llege and less likely to earn more than $30 000 (US) per year.19 However, like psychosis, thi s may be explained by the presence of many confounders inc luding pre-ex isting depression. Gruber et al. have recently published data indicating significant alterations in fronta l white matter tracts in chronic marijuana smokers. The authors suggest that these changes are associated with increased impulsivity, whi ch may contribute to the initiat ion of chroni c marijuana use or the inabili ty to di scontinue use20

HEALTH PROMOTION

Risk factors for marijuana use and abuse: Risk factors for marijuana use include male gender and age 18-25 , while risk fac tors for dependence, defi ned a a maladapti ve pattern of use despite negati ve effects, increa ed use, unsuccessfu l attempts at cessation and physiologic withdrawa l, include male gender, age 12- 17 and absence of post-secondary edu cati on4 Stinson et a l. 2 1 have underscored that cannabis abuse and dependence are genera lly phenomena of adolescence and young adulthood, and onset of dependence after age 30 is rare. Stinson et al. 's results confirmed that, unlike w ith alcohol (where ri sk of dependence persists for decades after first use) , there is a shorter developmenta l peri od of risk for cannabis dependence. As such, there is a window of opportunity in ea rl y adolescence for the implementati on of preventi on and intervention programs, in order to have max imum impact. A pro pecti ve longitudinal study of a community sample (n =

302 1) aged 14-24 years in Munich, Gennany,22 found that 56% of all repeated cannabis users (five times or more) still reported cannabis use at 4-year fol low-up . At 10-year fo ll ow-up, thi s proportion had decreased only sli ghtl y to 46 .3%. Among youth who are repeated cannabis u er , patterns of use remain table, and rates of cessation are low, until age 34. Such patterns suggest that preventi ve measures should de lay first use and reduce the number of uses, as these factors appear cruc ial in the transi tion to persistent and dependent use of cannabis.22

A lthough males may have hi gher rates of marijuana use, Schepis et a l. 23 have suggested, based on results from a cross-sectional survey of Connecti cut adolescents, that females may have a more rapid tran ition from initi al marijuana use to regul ar or dependent use. The

UWOMJ I 80 :21 Fall2011 33

authors also suggested that marijuana use was associated, not surprisingly, with ri sk behaviour participation (e.g. other substance abuse) and that partic ipation in extracurricular activities was protective agai nst marij uana use. A prospective cohort study of Swiss teenagers and young adu lts was performed to evaluate different lei sure time acti vities and the persons (e.g. partner, friend, sibling) with whom the acti vities were undertaken24 The choice of companions for leisure act ivity was more important than the activity itse lf as a predictor of initi ation and progression of cannabi s use, supporting the widespread view that peer influences are particularly important in young people 's risk behaviour . This finding was reinforced by data from the German study18 ci ted above, in which peer use of cannab is, stressful life events and alcohol dependence predicted long-term marijuana use.

Marijuana and tobacco: Health promotion for marijuana cessation is parti cul arl y important g iven the hi gh co-morbidity between marijuana and tobacco use, and the potentia lly damaging interact ion of these two ubstances on respiratory outcomes. Leatherdale, Hammond, Kaiserman et at.25 described results from a 2004 tobacco use survey of 20,000 young adu lt Canad ians (aged 15-24). The rates of marijuana use were highest among current tobacco smokers, and lowest among youth who had never smoked. Those who use marij uana are less likely to quit smoking (odds rati o 1.94); those who use marijuana dai ly are even less li ke ly to quit than those who have used at some point in the past 30 days 26 Thus, whil e marijuana use itself may or may not be assoc iated with an increased ri sk of lung cancer, marijuana use may secondaril y increase the ri sk of lung cance r through its assoc iati on with persistent to bacco use . Conversely, through use of prospecti ve survey methodology, Schaub et at.2° found that nicotine use increases the ri sk for both the initiation and the progression of cannabi s use. The authors also reported that tobacco use remai ned high even afte r reduction or cessation of cannabis use. Thus, there appears to be a bidirectiona l ri sk between tobacco and marij uana use, with use of either substance increasing the likelihood of using the other. Clini cians should ask about marijuana hi story and take marijuana use into account when recommending tobacco smoki ng cessati on measures for the ir patients, and vice versa.

Mental health disorders and use of cannabis: A study of 884 1 Australian adults aged 18- 85 year found that participants wi th affecti ve disorders and anxiety di sorders were at increased ri sk of harmful drug use and drug dependence.27 This corre lation was particularly strong for you ng males, a group already identified earli er as high-ri sk for marijuana dependence. Another study reporting on cannabis use disorders and mood and anxiety disorder co-morbidity showed that bipolar disorders, panic disorder with agoraphobia, and generalized anx iety disorder had the strongest associa ti ons wi th cannabis abuse and dependence. 17 Whi le the directionality o f thi s association remains unclear, one theory is that the experi ence of untreated affective disorders and anxiety disorders may lead to se lf­medi cati on with psychoactive substances such a marijuana. A uch, it is important for hea lth practitioners to identi fy and treat underl yi ng mental hea lth conditi ons in a timely and effective manner. Indeed, there is evidence that such practi ces can reduce marijuana use, as demonstrated by two randomized controll ed tri als included in a systematic rev iew.28 For exampl e, in a flu oxetine treatment group, cannabi use decreased in patients with depression. In patients with psychotic disorders , both olanzapine and ri speridone treatment groups also reduced cannab is use. From a health system-level perspecti ve, overcoming the treatment fragmentation between mental health and drug and alcohol serv ices would mean that the issue of comorbidity among clients (particularly young people) can be more adeq uately addressed.7

Treatment of marijuana use disorders: Despite public perceptions of marijuana as a relative ly innocuo us drug, exposu re. to psycho acti ve cannabinoids can induce st ro ng drug- seek mg behaviours; these are mediated by increased dopamine release m the brain 's reward pathway.29 Abrupt withdrawal of cannabm01ds after long-term exposure can produce dysphoric effects, wh1.ch ~ay contribute to relapse. Although cannabis shares neurobwlog1cal features associated with depe nde nce on othe r drugs , on ly approximately one-tenth of individuals who abuse cannabiS had ever rece ived treatment. 17 Psychosocial interventions, although effect1 ve in the short-term, often lead to long-term relapse, and the ava tlable behavioural treatments are only modestly effective. As such, there IS

a need to develop pharmaco logical intervention , and currently none have been validated through clinical trial s.25

As described above, cogniti ve impairments may not be fully reversible even I month after cessation of marijuana use. It remains unclear if these findings refl ect long-term effects of marijuana, or si mply an impairment of baseline cognitive functioning in marijuana users. Nonetheless, cogniti ve impairments in marijuana users may result in poor treatment response,3° particularly in light of the lack of motivation and increased impu lsivity that is associated wi th chronic marijuana use. Studies have suggested that cho linesterase inhibitors may ha ve a ro le in improving cann ab is- induced cognitive impairments, but these drugs have not yet been evaluated in humans for the treatment of marijuana dependence. Cogniti ve rehabilitation has improved function and treatment outcomes in individuals addicted to other drugs. ofuoglu et al. have thu suggested that improving cogniti ve function may serve as an important treatment strategy for marijuana use disorders2 6

Harm reduction through use of vapo urizers : Given the widespread use of marij uana, the increasing abuse and dependence on this sub tance, and the paucity of effective treatment trateg ies, it is important to consider harm reduction approaches to mitigate marijuana' potential adver e con equences. This pragmatic approach is particul arly compelling given marijuana 's increasing use for medicinal purpo es. Accord ing to resu lt from a 1998 Canadian survey, medica l use of marij uana was less common than its recreational use (2% versu 7%),31 but thi picture may change in light of the shi ft ing legal landscape surrounding medic inal marijuana. Cannabinoids acti va te the arne neurotransmitter pathways as endocannab inoids, produci ng effects ranging from analgesia to appetite stimulation to nausea reduction . They al o cau e a reduction of intraocular pressure, hence the usefulnes of marijuana in treating the ymptoms of g laucoma.32 The main challenge for the medi cal u e of cannab ino ids is the deve lopment of safe and effective methods of use th at lead to therapeutic benefi t, without respiratory consequences or other adverse effects.

Ea rl eyw ine and Barnwe ll 11 ha ve described the use of vapourizers among marij uana smokers : vapourizers release active cannabino ids but not smoke o r carcinogens a sociated with combu tion . The use of a vapourizer is assoc iated with decreased respiratory symptoms, and this effect increases with the amount of cannab is used. Furthem1ore, vapourizer can deliver ca nnabi s with no carci nogeni c potenti a l. This has important implications for safe use of. medica l marijuana as well as harm reduction among recreatwnal smokers. In one study, twenty frequent cannabi s users who reported respiratory complaints were eva luated before and after the use of a vapourizer for one month33 Among participants who did not develop a respiratory illness during the trial , there was a s ignificant improvement in respiratory symptoms and FVC and a non- ignifi cant improvement in FEY I . These improvements c~u ld be even more meaningful in cannabi s users who al o smoke tobacco The . authors c?ncluded, given . these. ~eani.n gfu l recovery of resptratory functiOn, that a randomized cltnt ca l tn al of the cannabis

34 UWOMJ I 80 :2 I Fall2011

vapourizer should be performed. The vapourizer has potential for the administration of medical cannabis and as a harm reduction technique, particularly for those uninterested in marijuana cessation or who have been chronic, heavy users.

CONCLUSION

Although the prevalence of marijuana use has not changed sign ificant ly in recent years, the higher cannabinoid content of current plants may be contributing to the observed increase in rates of dependence in ado lescents. Both phenomena - increased dose of psychoactive drug, and increased rates of serious dependence - have catalyzed more research into the long-term neuropsychi atric effects of marijuana use. Long-term marijuana use is associated with an increased risk of psychosi s and 'amotivational syndrome '. However, the direction of causation remains unclear, not least because the risk of marijuana dependence during ado lescence is clearly increased by co-morbid psychiatric di sorders and has been characterized as a fonn of 'self- medication '. Marijuana is also associated with specific long­term cogn itive abnormalities; the possibility of reverse causation seems remote for these findings, but further research is needed. Marijuana has immediate adverse effects on respiratory mucosa simi lar to tobacco; however, evidence for chronic respiratory disease re lated to marijuana is weak. For lung cancer, imilarly, heavy marijuana use produces metaplastic changes but there is no compelling evidence for an association with clinical di sease. The contradictory evidence for both conditions may reflect differences in the chemistry and cellular effects of marijuana as contrasted with tobacco, as well as the high frequency of joint exposure. In that latter regard, the more significant risk for respiratory illness, including malignancy, may arise from the strong association of tobacco and marijuana use, and the reduced likelihood of smoking cessation in the presence of joint dependence.

From the standpoint of health promotion, we can draw a number of key conclusions. Primary prevention of marijuana dependence wi ll require health education targeting pre-adolescence. The preva lence of comorbid psychiatric disorders in dependent adolescents highlights the need for an integrative approach to treatment and secondary prevention. Awareness of the conjoint use of tobacco and marijuana is important for clinicians seeking to promote smoking cessation. Lastly, vapourizers have the advantage of mitigating respiratory ri sk and may serve as an effective harm reduction strategy for those who are chronica lly dependent or using cannabinoids for clinica l indications.

REFERENCES

I. Mehra R, Moore BA, Crothers K, Tetrault J, Fiellin DA. The assoc iation between marijuana smoki ng and lung cancer: a systematic review. Arch Intern Med. 2006 Jul 10; 166( 13): 1359-67 .

2. Health Canada. Youth Smoking Survey 2006-2007 . http://www.hc-sc. gc. ca / h c -p s / t o bac- ta bac / resea re b - rec he rc h e /s t a tl _ s ur vey­sondage_2006-2007/table- 12-eng.php. 2008 Dec 22.

3. Health Canada. Canadian Alcohol and Drug Use Monitoring Survey : Summary of Results For 2009. bttp -ljwww bc-sc gc ca!bc-ps/drugs-drogues/statl 2009/summary-sommai re-eng pbp#cannabis. 20 I 0 Jun 30.

4 . Kandel D, Chen K, Warner LA, et al. Prevalence and demographic correlates of symptoms of last yea r dependence on alcohol, nicotine, marijuana and cocaine in the U.S. population . Drug Alcohol Depend 1997 ; 44 :11.

5. Sofuoglu M, Sugarman DE, Carroll KM . Cognitive functi on as an e mergi ng treatment target for mariju ana addi ction. Ex p C lin Psycbopharmacol. 20 10 Apr; 18(2): I 09-19.

6. Compton WM, Grant BF, Colli ver JD, Glantz MD, Stinson FS. Prevalence of marijuana use disorders in the United States: 199 1-1 992 and 200 1-2002. JAMA. 2004 May 5;291 ( 17):2114-21 .

7. Vandrey R, Haney M. Pharmacotherapy for cannabis dependence: bow close are we? CNS Drugs. 2009;23(7):543-53 .

' . ·. ·:~ H'E"ALTH PROMOTION ... _·~· ..... ~~ ·~z~.r.r ~~" ·. ~-~l_.

8. Raphae l B, Wooding S, Stevens G, Connor J. Comorbidity: cannabis and complexity. J Psycbiatr Pract. 2005 May; II (3): 161-76.

9. Tetrault JM , Crothers K, Moore BA, et al. Effects of marijuana moking on pulmonary fun ction and respiratory complications: a systematic review. Arch Intern Med 2007 ; 167(3): 22 1-228 .

I 0. Wu TC, Tashkin DP, Djahed B, Rose JE . Pulmonary hazards of smoking marijuana as compared with tobacco. N Engl J Med 1988 ; 3 18: 347.

II . Earleywine M, Barnwell SS. Decreased respiratory symptoms in cannabi s u ers who vapori ze. Harm Reduct J. 2007 Apr 16; 4: II .

12. Ha ll W, Chri stie M, Currow D. Cannab inoids and cancer: causation , remediation, and pal liation. Lancet On col. 2005 Jan;6( I ):35-42 .

13. Melamede R. Cannabis and tobacco smoke are not equal ly carcinogenic. Harm Reduct J. 2005 Oct 18;2:2 1.

14. Guzman M. Cannab inoids: potenti al anticancer agents. Nat Rev Cancer. 2003 Oct;3( 1 0):745-55 .

IS. Bolla Kl , Eldreth DA, Matochik JA, Cadet J L. Neural substrates of faulty decision-making in abstinent marijuana users. Neuroimage. 2005 ; 26(2): 480-492 .

16. Heming RJ , Better WE, Tate K, Cadet JL. Cerebrovascular perfusion in marijuana users during a month of monitored abstinence. Neuro logy. 2005 ; 64(3): 488-493 .

17. Fergusson DM , Poulton R, Smith PF, Boden JM. Cannabis and psychosis. BMJ. 2006; 332(7534): 172-175.

18. Moore TH , Zammit S, Lingford-Hughes A, Barnes TR, Jones PB, Burke M, Lewis G. Cannabis use and ri sk of psychotic or affective mental health outcomes: a ystematic review. Lancet. 2007 ; 370(9584): 3 19-328.

19. Gruber AJ , Pope HG, Hudson Jl, Yurgelun-Todd D. Attri butes of long­tenn heavy cannabis users: a case-control study. Psycho! Med. 2003 ; 33(8) : 14 15-1422.

20. Gruber SA, Si lveri MM , Dahlgren MK, Yurgelun-Todd D. Why so impulsive? White matter alterations are associated with impu lsivity in chronic marij uana smokers. Exp Clin Psychopharmaco l. 20 11 Jun ;19(3): 23 1-42.

2 1. Stinson FS, Ruan W J, Pickering R, Grant BF. Cannabis use disorders in the USA : prevalence, correlates and co-morbidity. Psycho! Med . 2006 Oct;36( 1 0): 1447-60.

22. Perkonigg A, Goodwin RD, Fiedler A, Behrendt S, Beesdo K, Lieb R, Wittcben HU. The natural course of cannabis use, abuse and dependence during the first decades o f life. Addiction. 2008 Mar; I 03(3):439-49.

23. Schepis TS, Desai RA, Cavallo DA , Smith AE, McFetridge A, Liss TB, Potenza MN , Krishnan-Sarin S. Gender differences in ado lescent marijuana use and associated psychosocial characteri stics. J Addict Med 20 11 ;5: 65- 73.

24. Schaub M, Gmel G, Annaheim B, Mueller M, Schwappacb D. Leisure time acti vities that predict initiation, progre ion and reduction of cannabis use: A prospective, population-based panel survey. Drug Alcohol Rev 20 10;29;378- 384.

25. Leatherdale ST, Hammond DG , Kaiserman M, Ahmed R. Marijuana and tobacco use among young adults in Canada: are they smoking what we think they are smoking? Cancer Causes Contro l. 2007 May; 18(4) :39 1-7.

26. Ford DE, Vu HT, Anthony JC. Marijuana use and ce ati on of tobacco smoki ng in adults from a communi ty sample. Drug Alcohol Depend. 2002 Aug I ;67(3):243-8.

27. Liang W, Chikritzhs T, Lenton S. Addiction. 20 11 Jun ; l06(6): 11 26-34. Affective disorders and anxiety disorders predi ct the ri sk of drug harmful use and dependence.

28. Baker AL, Hides L, Luhman Dl. Treatment of cannabi use among people with psychotic or depressive di sorders: a ystematic review. J Clio Psychiatry 20 1 0;7 1 :247- 54.

29. Vandrey R, Haney M. Pharmacotherapy fo r cannabi dependence: bow close are we? CNS Drugs. 2009;23(7):543-53 .

30. So fuoglu M, Sugarman DE, Carroll KM . Cognitive function as an e merging treatment target fo r marijuana ad di ction. Exp C lin Psycbopharrnacol. 20 I 0 Apr; 18(2): I 09- 19.

3 1. Hall W, Christie M, Currow D. Cannabino ids and cancer: causation remediation, and pal liation. Lancet Oncol. 2005 Jan;6( 1 ):35-42. '

32 . Yazulla S. Endocannab ino ids in the reti na: from marijuana to neuroprotection . Prog Ret in Eye Res. 2008; 27(5): 501-526 .

33. Van Dam NT, Earleywi ne M. Pulmonary function in cannabis users: Support for a c linical trial of the vapouri zer. lnt 1 Drug Policy. 20 10 Nov· 2 1(6):5 11-3. ,

UWOMJ I 80:2 I Fall 2011 35

An Interview with Dr. David Leasa

Lauren Sham (Meds 2014}, Abdu l Naeem (Meds 2014}, Joyce TW Cheung (Meds 2013}

T ln disaster management, where etiologie of disease can be unknown and every second is of the essence, a well­functioning intensive care unit (LCU) is paramount. The

SARS (Severe Acute Respi ratory Syndrome) outbreak in 2003 highlighted the importance of efficiency in meeting the challenges of medical urgencies. In an area where resources are limited, cri ses exacerbate chall enges with staffi ng shortages and bed reductions, compounded by disease transmission within the lCU , staff quarantine, emotional stre , and a constant influx of criti ca ll y ill patients I. However, the 2003 outbreak also presented itself as an opportunity to improve critical care delivery, with respect to implementing better infection control measures, developing software for handheld devices specific for SARS, and having regul ar teleconference call s to both combat the feelings of iso lation and increase information dissemination on this unknown illness 1• One needs passion and proficiency in handling "acute medica l problems where problems often come in undefi ned," says Dr. David Leasa, a London, Ontario based ICU phys ician.

Dr. Leasa was born and rai ed in Waterloo, Ontario, and studied Physiology and Pharmaco logy at the University of Western Ontario (UWO). He continued hi s studi es at UWO in medicine and completed hi s internal medicine residency there as well. After specializi ng in Respirology and Critica l Care he moved to Seattle, Washington to pursue a year of research. He moved back to Canada, worked at St. Joseph's Hospita l and later moved to University Ho pita! where he is currentl y working as an I U physician and Respirologist. When not in the hosp ita l, Dr. Leasa enj oys being outdoors. He likes to ki (even hope for a retirement in Whi stler!), swim, and run - a ll act ivities he fee ls help him lead a balanced healthy li fe.

Being a n ICU phys ician and a Respirologist is demandi ng. Dr. Leasa leads a very act ive and busy work life. He tends to have a week of "days" ( 12 hour shifts) in I U, alternating with a week of "ni ghts," and is on-ca ll some weekends. During ni ghts, a new initi ative is in place where the ICU staff has criti ca l care ou treach . Qualified ICU ph ys icia ns extend their experti se to other departments if they fee l a patient might end up in the ICU . By extending their services outside of the ir usual boundari es, they are ass ist ing patients

earli er, wi th the ai m of preventing ICU admi ssions. He also has a week in Extended ICU (E ICU) where he provides care for patients needing prolonged ventilator care for greater than three weeks. In addition to ICU, he spends one week every 2 months on the Respirology service taking consult . Finally, he also has a chest clinic that is evolving into providing care for chronica lly venti lated patients.

In the ICU, Dr. Leasa empha izes, "You need to have a team of people put forth what is the best management for that individual." This team approach reflects the dynamics on the wards. ln the ICU, all the physicians come fro m different pecialties but have added skills in critical care. (Critical care is an additional two-year RCPSC subspecialty after having completed a base specia lty.) Dr. Leasa admits that a he gets older, ICU may be too demanding (especially nights!) and that it wi ll be nice to be able to fa ll back on his outpatient pract ice. He enjoys chatting with hi s patients and meeting people in this sett ing. This prov ides continuity with patients who get very ill initia lly, but he can follow and see them in a different etting as they recover - see thei r per ona li ty and who they are as indi viduals, omething he cannot alway experi ence in the !CU.

However, hi s pass ion has a lways been intensive care. He enj oys managing and problem- o lving acute care Res pirology ca es in the ICU , fro m pneumonia to acute re piratory distress syndrome (ARDS), to broncho copies and pleural effu ions.

Th e practice of bot h ICU and Respirology has led Dr. Lea a to hi s interest in long-tern1 mechanical ventilat ion - he is known as the " home venti lation doctor. " He i presently involved in an initiative to provide care for stable chronically venti lated patients by moving them from the ICU environment to other community venues, inc luding home if pos ibl e. Dr. Leasa believes that "to do it safely, properly and effecti vely, we need to do it using a systems approach." He wou ld want to not on ly prevent patients from ending up in the ICU agai n but also improve the ir overa ll qua lity of life through care at home or in the community. At the moment, he is tty ing to advocate that thi s initiative needs the proper funding: if we can prevent these patients from us ing ICU beds a nd shift these resources to the community, there wou ld be benefits for all. Hi s vision for this project Involves developmg a community-ba ed

36 UWOMJ I 80 :2 1 Fall2011

model for the region of Southwestern Ontario. Currentl y there are more than 180 pat ients who are on both non-inva ive and invasive ventil ation in our catchment area. Ventilator technology has changed dramatically over the past decade including its ease of use and increasing application using a noninvasive mask interface . However, several hurdl es remain inc luding cost, need for trained community careproviders and for patients/famil y members to be ed ucated and empowered. Dr. Leasa is currentl y trying to create a coordinated system of people who understand the complicated nature of the care for these chroni cally ventil ated patients. One important task i to identify and support those pati ents for whom chroni c ventilator care at home improves qua lity of life. Importantly, this needs to be done in a way that coordinates all caregivers ' skill s so that pati ents do not end up back in the ho pital. There are many patients that can benefit from this type of technology (especia ll y those with chroni c neuromuscu lar di sease), but in order to do thi s safe ly and effecti vely, a preplanned system needs to be in place, and thi s is what Dr. Leasa is trying to help e tabli h.

The future of critica l care holds a plethora of possibi liti es, but also many difficult ethica l issues. Because patients in the ICU are often amongst the sickest people in the hospita l, the difficult issue of death and dying often arises, and proves to be a challenge for both families and the JCU team. Dr. Leasa believe that an important step in improving care for patients in the ICU lies in education on the taboo subj ect of dying. Due to advances in med ical technology, patients can be kept a li ve fo r longer than their bodies would natura ll y be able to ustain . Difficult issues arise when one has to cons ider the quality of life for a pati ent who is unconscious and unable to survive without the aid of sophisticated machinery.

Dr. Leasa is not one unfamiliar with making difficult decisions. Recently, he bad to sit down with the family of a 95 year o ld man who bad a myriad of comorbiditi es, none of which were easy to manage. As medical students we learn: "primum non nocere," or "first do no harm." You would think that everyone would want to give this man as comfortabl e a death as possible. However, hi s fa mily expressed that he wanted to li ve unti l he was I 04, and wanted everything possib le done for him, from intubation to chest compressions. Perhaps it was guilt from neglect in previous fa mily confl icts, or a just desperation to cling onto any semblance of life possible, but these situations are not always as clear as they appear, neither to the family nor to the clini cian.

So how do we open up and begin talking about these diffi cult issues? Dr. Leasa believes the family unit is critical in these di scussions. The difficulty in talking about the deteriorating health of a loved one is trying to figure out what the patient would have wanted for him or herself. He recall s some famili e who have not seen or talked to Dad in ten years but think that prolonging care is what he would want. As criti cal care has bettered itself with improved communication, so too wou ld families. Dr. Leasa lives out this philosophy, which was inspired by the mentors he has had over the years: "The physic ians I learned a lot from were those who sat with patients and talked honestly to them," he said, noting that they didn 't keep a di stance but instead liked to understand the person they were treating.

As past-president of the Canadian Criti ca l Care Society (CCCS), Dr. Leasa has participated in many activities to enhance the quality of care in ICUs across the country. The CCCS has guidelines on how to assist in difficult issues at the bedside, as well as advocate for improvement of patient and family experience in the ICU. He notes that critical care has had its shake ups, including the SARS outbreak which was an eye opener for governments and health care professionals alike, but they learned that critical care had to be done as a collective. He believes that they have been doing a good job in Ontario2 in dealing with increased occupancies and having clear

pl anning for surges. He notes, " If you stop criti ca l care, you stop everything. Everything starts to back up. " He also thi nks we need more di scussions on the ethical use of resources: not ju t at the level of the indi vidua l, but on a soc ieta l level. He poses the question , " If we had SA RS again, and we ran out of ventil ator and ICU beds ­what would we do? Would we use a predetennined algorithm to see who gets a ventil ator and who does not?" He acknowledges that it is difficult to have these di scus ions, but working through these scenarios is necessary. After go ing through SARS, politic ians fin all y understood it, even expressing th at "SARS was good for criti ca l ca re - it created outreach teams, put more nurses into the system, and looked at what 's go ing on with respect to resource - what they are, and where they are."

Dr. Leasa be lieve that the general public needs to be better educated on the purpose of the ICU, but a lso that it has its limits. He and hi s colleagues spend a lot of their time di scuss ing what critical care resources can and cannot do. Education of the genera l public becomes increasingly important as the vo lume in the ICU increases. With the current advance in li fe support sy tems we are able to extend li fe that previously would have ended . This leads to new cha ll enges. He wants people to understand that we cannot cure everything, and we cannot always delay death. Many times patients are chroni ca lly ill at the end of their li ves and are in a proce s of dyi ng. Should ICU care and a ventilator be part of that death process? There is still a gap between what patients and or the ir fam ili es expect and what our current medi ca l technology can ethicall y and reasonably deli ver. Dr. Leasa is hoping we can bring the two c loser together.

REFERENCES

I. Communication in the Toronto criti ca l care communi ty: important le son learned during SARS. Christopher M Booth and Thomas E Stewart . Crit Care. 2003 ; 7(6):405-406. http://www. ncbi.nlm .nih .gov/pmc/arti c les/ PM C37438 1/

2. http ://www. hea lth .gov.on .ca/eng l i sh/prov i ders/program/cr i tic a I_ care/ cct_strategy. html

UWOMJ I 80 :2 I Fall 201 1 37

A lung mass and digital clubbing in a young woman

Julie Lebert (Meds 2013), Joyce TW Cheung (Meds 2013)

Faculty Reviewers: Dr. David Leasa, Dr. S. Nelson

I nflammatory myofibroblastic tumours (IMT), also known as plasma cell granul omas or inflammatory pseudotumours, are the most common paediatric primary lung tumours.1 Patients present

at a mean age of 9.7 years, maki ng it an unusual adult diagnosis2

IMTs are extremely rare, accounting for only 0.05% of all thorac ic procedures 3 !MT bas traditi onally been class ified as a benign tumour, but recent studie suggest loca lly aggressive behaviour and ma lig nant pote nti a14 Radi og raphica ll y, it is impossib le to differenti ate between an !MT and a malignant mass,4 as the presentation of the tumours are highly variable. IMT may be cystic or homogeneous, endobronchial or parenchyma1. 1 It is thought to result as an inflammatory reaction to an infecti on or an underl ying low grade mali gnancy. Patients usually present with loca l mass effects with or without systemic features such as fever, weight loss, microcytic hypochrom ic anemia, polyclonal hyperglobulinemi a, elevated ESR, and hypertrophi c osteoarthropathy (HOA) 2 •4 Due to its variable natural history, compl ete surgical excision is the treatment of choice.3

CASE REPORT

A 24-year-old female presented to our institution with a four-month history of left sided pleuritic chest pain . The pati ent had a hi story of hypochromic microcytic anemi a and was currently taki ng oral contrace pti ve pill s a nd iro n s uppl e me nts. Upon ph ys ica l examination, a review of systems revea led that she had a non­productive cough, drenching night sweats, fatigue and had lost I 0 pounds. She a lso reported joint pai n and morning stiffness, predominantl y in volving her wrists, knees and ankl es. The patient had recentl y fini shed a ten-day course of antibi oti cs with no symptomatic improvement. She was a non-s moker with occasional marijuana and alcohol use. Her family hi tory wa negati ve for mali gnancy, but her brother had asthma.

The pati ent had tendemes to palpation over lateral chest wa ll on physica l examination. Bilateral clubbing of the dig its wa noted .

Laboratory investigations revea led hypochromic microcytic anaemia (haemoglobin leve l of 80 g!L, a mea n corpu cular volume of 77.1 fL , microcytic hypochromasia). Chest plain fi lm showed a mass- like conso lidation in the left lower lobe with enlargement of the left hilum. Computed tomography (CT) showed a heterogeneous soft ti ssue rna extending from the lateral che t wa ll to the inferi or aspect of the left hilum. No cav itation or characteristic ca lci fi cation was identified. Small blood vessels were seen within the les ion, but did not have the appearance of normal lung vesse ls. The mass extended centra ll y to contact the inferior aspect of the left hilum . No lymph node, chest wa ll in vasion or rib destructi on were identified .

Exploratory left thoracotomy with enucleation of the tumour was performed and an intra-operative frozen section of tumour (3 .2 x 2.0 x 1.5 em) showed hi stology consistent with benign spindle cell

tumour. Fo ll owing this procedure, the tumour increased in size from 4.1 em to 5.4 em over a s ix month peri od. Thi s recurrence of the tumour suggested locall y aggress ive behaviour; and it was decided to perform a left pneumonectomy. Surg ica l patho logy showed no overt cytoli c atypic, however vascular invasion and invo lvement of the diaphragmatic ti ssue were evident. Clear resection marg ins were achi eved in the pneumonectomy and resecti on of di aphragm. Adjuvant chemotherapy or radiat ion was not recommended .

DISCUSSION

Clinical manifestations

Inflammatory myofibroblastic tumour (I_MT) is a rare tumour that is mo t commonl y a ociated with the paedi atric population. Numerous studies, however, bas shown that IMT can affect people of any age and equally affects both gender .2.4 It i a lso important to note that IMT can occur throughout tbe body. In a review of 44 pati ents with IMT, Ko ach et a l. reported IMT occurring in the liver, gallbladder, orbit, mediastinum, neck soft tissue, trachea, bowel , brain and others. 4 The organ wi th the highest frequency of diagno is is the lung (9 of the 44 patients) 4

The presentation of IMT depends on the location of the tumour and i influenced by local mass effects from the tumour size.4 IMT can present with a variety of symptoms, both systemic and localized, uch as anaemia, weight loss, feve r, pain, and mas .2 For example, in

thi s case, the patient presented with pleuritic chest pain .

The lung is the most common location of this neoplasm but has been reported to present with extrapulmonary symptoms . There have only been a small number of case reports where hypertrophic osteoarthropathy (HOA) was ob erved .5·6•7 Furthermore, these cases occurred in children with no reported adult cases with HOA. The etiology o f HOA in assoc iation with IMT of the lung is unknown.5

Pathology

Inflammatory myo fibrobl astic tumours pathologically consist of myo fibrobl a tic spindle cell s with an inflammatory ce ll infiltrate.5

The appearance of IMT under microscopic examination is variable both between the different site of occurrence and between patients with tumours in the same location .4

The etiology of IMT is still under debate and current opinion is changing as new information, especia lly genetic analysi of the tumour cell s, comes avai lable. It was initia lly proposed that IMT arises from uncontrolled, excessive immune response to ti ssue injury (most likely from infection); however, more recent studi es suggest that it might in fact be a true mali gnancy.4•8 Thi s is supported by reports of distinct mutations in the cell s of these tumours and by the tendency for local recurrence and invasion , distant metastas is and potentially sarcomatous degeneration .3.4.S

38 UWOMJ I 80:2 I Fall 2011

Diagnosis

A diagnosi s of IMT impossible to determine c linically as it is genera lly a di agnosis of exclusion. Upon imaging, a mass wi ll typically be identified; however si nce IMTs occur with a wide range of radiol ogical characteri stics, imag ing does not often contribute to the diagnosis 9 Radiologica l reports on IMT, show that these tumours can be cystic or homogenous, endobronchial or parenchymal, and with or without clear margins.9 These qualities make IMT difficult to distingui sh fro m infectious or malignant pathologies.4·9 Furthermore, biopsy of these les ions rarely results in a conclusive diagnos is, as IMT can mimic many other pathologies such as fibrous hi stiocytoma, leiomyosarcoma or fibrom atosis.2 A confident diagno is can thus only be made fo llowing surgical resection and pathological anal ysis of the mass . s

Treatment

There are several treatment options to consider after IMT is diagnosed. The first line treatment is surgical exci ion since IMTs have the potential to local recur, be loca lly invas ive, and occasionally metastasize. Other suggested options include NSA IDs, steroids, radiation, chemotherapy and observation only.

In a retrospective study, 25 patients had complete resecti on of the tumour.3 The 30-day post-operative mortality was 4% and morbidi ty was 8%.3 The 10-year surviva l was 89%, with one patient's death due to extensive sarcomatous recurrence 2 years post surgery.3 This study demonstrates that IMT has an exce llent prognosis with complete surgical excision, however must still be considered a malignancy with the potential to have di stant metastasis, local recurrence and sarcomatous degeneration .3

While surgery has shown po itive results in patient cure rates, the natural hi story of IMT has not been well studied 4 In a case series, it was noted that local recurrence occurred in 8% of pat ients where resection was attempted4 Local recurrences tended to occur where complete resection of the tumour was not possible or where radiation or chemotherapy was not received 4

CONCLUSIONS

IMT is more common in the paediatric population and rare in adu lts. However, it should be considered on the differential diagnosis when a mass presents in a non-smoking adult.8

REFERENCES

I . Chen, C.-K. ; Jan, C-1. ; Tsai , J .-S .; Huang, H.-C.; Chen, P.-R.; Lin, Y. -S. ; Chen, C.-Y. ; Fang, H- Y. lnflammatory myofibroblastic tumor of the lung ­a case report. Journal of Cardiothoracic Surgery. 20 I 0; 5: 55-58.

2. Coffin, C.M.; Watterson, J. ; Priest, J .R.; Dehner, L. P. Extrapulmonary in fl ammatory myofibrob lasti c tumor (Inflammatory Pseudotumor). The American Journal of Surgical Pathology. 1995 ; 19(8): 859-872.

3. Fabre, D.; Fadel, E.; Singhal, S.; de Montpreville, V. ; Mussot, S.; Mercier, 0. ; Chataigner, 0 .; Dartevelle, P.G. Complete re ection of pulmonary inflammatory pseudotumors has excellent long-term progno is. General Thoracic Surgery. 2008; 137(2): 435-440.

4 . Kovach, S.J .; Fischer, A.C. ; Katzman, P.J .; Salloum, R.M. Ettinghausen, S.E.; Madeb, R.; Koniari s, L.G . Inflammatory Myofibroblastic Tumors. Journal of Surgica l Oncology. 2006; 94: 385-391.

5. Pichler, G. ; Thalhammer, G.; Muntean, W.; Zach, M.S. Arthralg ia and di g ita l c lubb ing in a child : hype rtro phi c osteoa rthropathy wi th inflammatory pseudotumour of the lung. Scandinavian Journa l of. Rheumatology. 2004; 33: 189-1 9 1.

6. Mas Eselles, F.; Andres, V. ; Vallcanera, A. ; Muro, D.; Cortina, H. Plasma cell granuloma of the lung in childhood: atypical radiologic findings and association w ith hypertrophic osteoarthropathy. Pediatric Radiology. 1995 ; 25: 369-372.

7. Mikou, N .; Balafrej, A. Pulondary fibro-xanthogranuloma associated with renal amyloidosis in a 5-year-old child . Arch Fr Prediatr. 1993 ; 50: 577-579.

8. van den Heuvel, D.A.; Keijsers, R.G.; van Es, H. W.; Bootsma, G.P.; de Bruin, P.C.; Schramel, F.M.; van Heesew ijk, J.P. In vas ive inflammatory myo fibroblasti c tumour of the lung. JO URNAL 2009; 4(7): 923 -926.

9. Rasa lkar, D.D.; Chu, W. .W. ; To, K.F.; Cheng, F.W.T. ; Li , .K. Radi ologica l appearance of infl ammatory myofibrobl asti c tumour. Pedi atri c Blood & Cancer. 20 I 0 ; 54: I 029-103 1.

UWOMJ I 80 :2 I Fall 2011 39

The economics of health and healthcare: a primer for the medical student

Hang Shi (Meds 2013)

Faculty Reviewer : Dr. Greg Zaric M.ASc, MS, Ph.D.

T he Canadi an medica l tudent, much like the Canadian publi c, is proud of its healthcare system but believes it is in need of enous reform.1 The perception is o ften that cost are

increasing to unsustainab le levels, with the conundrum that the y tern still doe not deli ver a much a it hould, to as many as it

should, or in a timely enough fashion2 In a 2011 national survey, only 5% graded the hea lthcare y tern a excellent. However, less than a third of a ll respondents be li eved they had a strong understanding of how the healthcare ystem worked 3 How can one properly rate a system they do not understand? While medica l students have a bas ic practical understanding of the medica l system, they are found lacking when it comes to the economi c theorie and principles that govern hea lthcare.4 Thi s i not surpri sing given the very limited time that can be allocated out of packed medi ca l curriculums5 The concern nevertheless remains that medical students may be unequipped and unprepared for their future rol e in hea lthcare resource a ll oca tio n and management. Witho ut an appreciation o f some basic tenet of hea lthcare economics, having a healthy discussion, taking a positi on, and making a well- in fo rmed deci ion on issues o f hea lthcare system will be diffi cult. The purpose of this primer is to introduce to the medical student the most fundamental economi c concepts and how they are pertinent to healthcare. Ultimately, it will be up to the students themselves to buttress their knowledge in thi increas ing ly important subject area ; thi s editori al can only hope to whet the palate just enough to encourage further ex ploration.

HEALTH CARE IS A SCARCE GOOD

The fundamental problem that underlines the study o f economi cs is ba ed on the s imple premi e that resource are finite whil e human needs are infinite6 When thinking about a tangibl e good uch a foss il fuels, the idea is easy to grasp. Everyone want an unlimited supply of fossil fu els to power their generators and run their machines. However becau e thi re ource i ca rce, there need to be a system that decides the a ll ocati on: namely who gets it and how much they can get. Economists concern themselves over the best way thi s a ll ocation shou ld be made, and a k themse lves how thi a ll ocation can be the mo t effi c ient while at the same time the most equitabl e.

When it comes to any good produced in the economy, even one as complex as healthcare, the fundam ental problem sti ll remains. The producti on of healthcare require the mu lti tude o f raw materia ls and suppli es required for equipment and facilities. In addition, it requires the time and tra in ing of healthca re worker .1 All of these, including time, are ca rce resources. Indi viduals se ll their time for wages and will even re fu se work and wage if it " isn' t worth their time." People view their time as a va luable resource that if used for work, can no longer be used for other acti viti e such as le isure.6 In much the arne way, once scarce resources are devoted to the production of

healthcare, they can no longer be used in the production of other valuable goods. Each joule of energy used to power a Magnetic Resonance Imaging (MRI ) machine is one that cou ld have been used to power a school. Each year tra ining one doctor cou ld have been used to tra in several economists. (It takes more resources to train a doctor than an economist).

One aspect of macroeconomic theory tries to determine how a nation's scarce resources should be best a llocated between its variou sectors. When policymaker decide on more MRJs and increasing the number of residency spot , it means we have to g ive up more of something else. Consider the foll owing: Canada 's Gross Domestic Product (GDP) has increased an average of 1.7% ann ually over the last decade.8 GDP i a measure that adds up a ll the goods and services that an economy produces per year. This indicates that on average, the Canadian economy grew by I . 7% each year over the last decade. The healthcare sector has increased by an a erage o f 4.7% annually over a s imilar period.9 If the entire economy is viewed as a pi e, then this mean that while each year the pie get a little bigger, it has not been able to keep up with the increasing s ize of the hea lthcare lice. If more of the pie is being di tributed to healthcare, then less is left over fo r va ri ou sectors such as educat ion agriculture, or high-tech indu try. Everyone rea li ze that healthcare i ~ important. The difficult questi on is how important. If for example, we va lue an additi onal unit of hea lthcare more than an addit ional unit of national de fense, then foregoing more de fen e for increased pending on hea lthca re benefit oc iety. If our value were reversed

then additional spending on hea lthcare would result in Ie s sociai bene fit. Deciding how much a nati on should spend on hea lthcare is a difficult question beca use it ca ll into question our value and forces u to a k how much we va lue hea lthcare over everything el e.

ECONOM ICS A A SOCIAL SCIENCE: UNDERSTANDING THE POWER OF INCENTIVES

While the fi e ld o f modem economi cs relies on a empirical-based approach with tati stical analys is, the fi e ld has it roots in the ocial sc iences. At its hea11 lies the desire to understand the decision making of individua l in their production or consumption of goods or erv1ces 6 Economists assume that decision makers are rational and

make choices that be t further their own ends. By under tanding the mcenll ves that indi vid uals face and how these then motivate a particular course of action, economists can predict and there fore model the outcomes.6.7

. . When thi s modeling i app lied on a larger cale to group of md1V1dual s, economists hope to better understand and predict the consequences 111 the economy based on changi ng incentives. For example, . when it comes to physicians deciding the ir location for pract .. ce, 1ncen t1 ves ~lay a hug~ ro le .7·10 As recently as 2006, 1 in 9 phys1c1ans educated 111 a anad1an med1ca l schoo l practiced in the

40 UWOMJ I 80:2 I Fall 2011

United States. 10 Therefore, they contributed nothing to the production of healthcare in Canada. In trying to understand and reverse thi s phenomenon, anadian economist and poli cymakers have identified a number of incentive at play. The most famili ar is the remunerati ve differenti al with the appeal of higher net income in certain specialti es in the US (due in part to their lower taxation rates). 'o By identi fy ing the pertinent incenti ves, policymakers can dev ise new strategies to alter them.

However, policymakers al o need to be care ful due to the unde irable con equences that may result when all incenti ves have not been taken into accoun t. In many cases, hidden incenti ves are overlooked and lead to unintended consequences. For example, in the physician-patient relation hip, the phy ician is not onl y an agent hired to act in the be t interest of the patient but is also the sell er of health ervices.7 In a fee-for-service compen ation method, the idea is to compensate the physician based on the services the patients receive. Phys ician who perform more services are thought to provide more healthcare and should be compensated accordingly. However, since the income of the phy ician is linked to how many services he or she provides, there is an incenti ve to promote more procedure than would otherwise be nece ary.11 These additional services are not only wasteful fo r the economy and lower effi ciency, but they may in fact do harm by leading to poorer outcomes in patient who receive superfluous procedures.7•11

HOW TO COMPARE APPLES AND ORANGES: VALUATION AND COST-BENEFIT ANALYSIS

The focus of hea lthcare di scussion is frequentl y directed at curbing the ri sing costs, and this cost cri sis of hea lthcare dominates the headlines.12•13•14 It sometimes becomes easy to forget that we value hea lthcare because we want more of its output: health itself. The va lue of healthcare is not in the number of patient appointment or pill s prescribed, but in the number of li ves saved and the improvement in health outcome. By placing a va luation on health , the important outcomes such as quanti ty and qua lity of life can be mea ured and expressed. If two medica l intervention have equivalent cost, and intervention A can add 3 years to life expectancy and intervention B only adds one year, it becomes quite clear which is superior. In evaluating any project or program, it is important to compare the va lue of what was bought to its cost. Economists use this principle of cost-benefit analysi when evaluating healthcare programs.7

When applied on a larger sca le, it offers the potential for comparing different healthcare interventions and even comparing program in health and non-health sectors. Noti ce that the interventions in the examples above could have been completely unrelated . Intervention A could be a cancer fi ghting drug and intervention B a surgical procedure for coronary heart di sease. By placing a valuation on both the inputs (the costs of production) and the outputs (the benefits of health improvement) , unrelated interventions can be compared. Through a comprehensive cost­benefit evaluation, economic analysis can help policymakers make difficult deci sions such as which projects to all ocate more resources into, assessing whether a new intervention is superior to the old standard, and in choosing between comparable alternatives7, l6 If applied across all healthcare sectors, policymakers can transfer funding from high-cost low-benefit programs with the reallocation of these resource into low-cost high-benefit programs. By minimizing costs and maximizing benefit, the overall effect has to potential to improve efficiency in the system and increase productivity.7·15

CONCLUSIONS AND LIMITATIONS

Economic principles and methods offer an approach to addressing healthcare problems. Many observers claim that economics is irrelevant to the study of health and some have argued that health

care is fundamenta lly so di fferent from other good that fina ncial incenti ves do not play much of a role. Many will argue that when dea ling with life and death, hea lthcare consumers cannot be expected to maintain rati onal thinking7·15 Empirical evidence suggests thi s is too extreme a posi ti on.? Price and financial incentives definitely do influence both the production and the consumption of hea lthcare. The more challenging questi on is to what ex tent it doe . The hea lthcare sector has a unique combinati on of fea tures: the prominent public sector, restri cti ons on competiti on, and lack of informati on. Combining this with the ex tensive uncertainty that ex ists both in the suppl y and demand side of hea lthcare complicates economic analyses. 7 With certain good , both suppli er and consumer have a good understanding of the product. For example, with orange j ui ce, upplier know how many oranges are needed to produce the juice

and are confident of the quali ty of the juice, and consumers know how much sati sfaction they will rece ive when drinking a unit of the juice. With hea lthcare, both the phys icians and pati ents are often uncertain of the outcomes. Rheumatologists are often uncertain of how pati ent will respond to a parti cular anti-infl ammatory and pati ents themselves are un ure of the benefit to their length or quali ty of li fe . With di fficulties in measuring outcome and va luation, the accuracy of the analy is can often be ca ll ed into questi on. In the end, modeling can only be as good as the informati on input. Nevertheless, economic principles and their methods can be a powerfu l and important tool when thinking about is ues in hea ltbcare. One imply has to realize that li ke all too ls, economic analysis in hea lthcare is imperfect and subject to limitations.

REFERENCES

I. MacQueen K. Our health care delusion. Macleans. Jan 20 II . 2. Canadian Institute for Health In fo rmation. Hea lth Care in Canada 2009: A

Decade in Review. Ottawa, Ont. : C!HI , 2009. 3. Deloitte Centre for Health Solutions. 20 II Survey of Health Care

Consumers in Canada: Key Find ings, Strategic Implications. Deloi tte Development LLC. 20 II .

4. Patel MS, Lypson ML, Davis MM . Medical student percept ion of education in health care ystem . A cad Med. 2009 Sep;84(9): 1301-6.

5. Bein B. Medical Students Not Satisfied With Training in Health ystems, Medical Economics. AAF P ews Now. Nov 2009. <http -ljwww aafp org/ on I i ne/en/home/publ icat ions/news/news-now/res ident-s tudent- foc us/ 200911 25med-econ-trng html>

6. Gregory Mank.iw et. al. , Principles of Microeconomics. el on College Indigenous. 4th Canadi an Edition, 2008.

7. Folland S, Goodman A, Miron . The Economics of Health and Health Care. Pearson. Fifth Edition, 2007

8. Canadian Industry tati ti cs. Gross Domestic Product (G OP) and GOP Growth : 200 1-20 10. Canadian Economy (NAIC 11 -91). tatistics Ca nad a . < http '// ww w ic gc ca / e ic / s it e/c is - s ic nsf/e ng / h 0001 3 htm l#vla2a>

9. Canadian Insti tute fo r Health In fo rmation. ational Health Expenditure Trends, 1975 to 20 I 0. Ottawa, Ont.: C!HJ , 20 I 0.

I 0. Phill ips R.L Jr, Petterson S, Fryer GE Jr, Rosser W. The Canadian contri bution to the US physician workforce. CMAJ. 2007 Apr I 0; 176(8): 1083-7.

II . Broom berg J, Price MR. The impact of the fee-for-service reimbursement system on the utilisation of hea lth services. Part I. A rev iew of the determinants of doctors' practi ce patterns. S Afr Med J. 1990 Aug 4;78(3): 130-2.

12. 12. Sibonney C. oaring costs force Canada to rea ess health model. Reuters. May 20 I 0. <http 'Uwww reuters com/article/?0 I O/OS/31/us-heal th-idUSTRE64U3X020 I 00531 >

13. 13. Mason G. This health-care crisis wi ll require more than aving around the edges. Globe and Mail. Jan 20 I 0. <hnp '//www theg!obeandmail com/ news/opinions/thi s-health-care-cri sis-wi 11-requi re-more-than-say i ngs­around-the-edges/article 1446642/>

14.Canadi an Hea lthca re in Cri is. CBSnews. Feb 2009. <h.ttp,;lL www cbsnews com/stories/2005/03/20/health/main68180 I shtml>

I 5. Cutler D. Your money or your health . Oxford Uni ver ity Press. New York 2004.

16. Robinson R. Cost-benefit analysis. BMJ. 1993 Oct 9;307(6909):924-6.

UWOMJ I 80:2 I Fall 2011 41

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