abscess evaluation using bedside ultrasonography

7/23/2019 Abscess Evaluation Using Bedside Ultrasonography

http://slidepdf.com/reader/full/abscess-evaluation-using-bedside-ultrasonography 1/8

Abscess Evaluation using Bedside

Ultrasonography

Updated: Jul 10, 2013

Author

Lars J Grimm, MD, MH House Staff, Department of Diagnostic Radiolog, Du!e Uni"ersit

#edical $enter

Disclosure: %othing to disclose&

$oauthor's(

!ristin A "armody, MD Assistant )rofessor of *mergenc #edicine, +oston Uni"ersit

#edical School Director of *mergenc Ultrasound, +oston #edical $enter

-ristin A $armod, #D is a mem.er of the follo/ing medical societies: American $ollege of

*mergenc )hsicians, American nstitute of Ultrasound in #edicine, and Societ for Academic

*mergenc #edicine

Disclosure: %othing to disclose&

#ultimedia i.rarReferences

#vervie$

A.scesses and other superficial soft tissue infections are common presentations to the emergencdepartment '*D(& n a su.set of patients, the phsical eamination re"eals a grossl fluctuant

su.cutaneous collection that is indicati"e of an a.scess& n man cases, ho/e"er, the clinical

presentation is not that clear& )hsical eamination alone is often inadeuate /hen differentiating

.et/een simple cellulitis and deeper soft tissue infections&415 6hese 2 disease entities are managed

differentl, and misdiagnosis can lead to unnecessar painful procedures or an increase inmor.idit, time lost, or cost to the patient&42, 35

Ultrasonograph has emerged as an increasingl "alua.le diagnostic tool to help /ith decision7

ma!ing& Se"eral recent *D studies ha"e demonstrated that .edside ultrasonograph significantlimpro"es clinicians8 a.ilit to differentiate .et/een cellulitis and a.scess and, thus, to initiate the

most appropriate treatment from the outset&49, 5 6he ad"antages of .edside ultrasonograph

include lo/ cost, porta.ilit, patient comfort, speed of detection 'usuall ; 1 min(, and /ide

http://www.acep.org/


http://www.aium.org/

http://www.saem.org/


http://emedicine.medscape.com/article/214222-overview


http://www.aium.org/








a"aila.ilit& Additionall, if a fluid collection is detected, ultrasonograph can .etter locali<e the

fluid for su.seuent aspiration or incision and drainage&

%ndications

• )atients /ho present /ith locali<ed signs of s/elling, pain, and erthema, and in /hom

cellulitis and a.scess might .e present, are ecellent candidates for .edside

ultrasonograph&

"ontraindications

• %o contraindications eist to using .edside ultrasonograph to differentiate .et/een

simple cellulitis and a.scess&

Anesthesia

• %o anesthesia is reuired, although analgesia should .e considered to increase patient

comfort and ease of scanning&

E&uipment

• )orta.le .edside ultrasonograph machine /ith a high7resolution linear transducer

• $onducting gel

• %onsterile glo"es

• Standoff pad 'optional(

'ositioning

• 6he patient should .e positioned so that the full area of interest is eposed and readil

accessi.le to the eaminer&

• =hile dressings and clothing should .e remo"ed for complete "isuali<ation, optimal

eposure must .e .alanced /ith appropriate draping of potentiall sensiti"e areas&

(echni&ue

etup






Set up needed euipment at the .edside& Start /ith the linear transducer set at a freuenc

.et/een &0 and >& #H<& f a deeper collection is suspected, consider s/itching to a cur"ilinear

pro.e set at 3& #H<&

)osition the patient as descri.ed a.o"e and clear the area of eamination&

'rocedure

)lace the pro.e at the .order of the region of interest and .egin scanning the length of theaffected area& 6his should allo/ for transition from normal to affected tissue for comparison&

*tend the area scanned to completel "isuali<e the edges of the infection in one plane&

Repeat the scan in an orthogonal plane to form a mental 37dimensional image of the area of

interest&

dentif normal su.cutaneous tissue, fascial planes, and muscle as landmar!s for comparison&

Also .e sure to identif an ad?acent structures of interest, such as .lood "essels or peripheralner"es '/hich can ha"e a honecom. appearance, see .elo/(&

Ultrasound image of normal soft tissue&

$ontinue scanning the region of interest to characteri<e the presence of fluid collection, theetent of collection, the depth of collection, echogenicit, and heterogeneit&

$onsider using a s!in mar!er /hile scanning to mar! sites for su.seuent aspiration or incision

and drainage&

6he "ideo .elo/ depicts demonstration of ultrasonographic a.scess e"aluation&

Demonstration and eplanation of ultrasonographic a.scess e"aluation using a linear pro.e&@ideo courtes of #eghan -ell Her.st, #D& Also courtes of ale School of #edicine,

*mergenc #edicine&

%mage interpretation



%ormal su.cutaneous tissue is hpoechoic /ith strands of hperechoic connecti"e tissue& Bascial

planes are highl hperechoic, and muscle tissue demonstrates a characteristic striated

appearance& @ascular structures are anechoic and usuall compressi.le /ith the transducer&

$ellulitis results in hperechoic su.cutaneous fat lo.ules floating in edematous fluid& 6his is

classicall descri.ed as cobblestoning , and is sho/n .elo/&

Ultrasound image of cellulitis /ith co..lestoning&$o..lestone appearance& @ideo courtes of #eghan -ell Her.st, #D& Also courtes of ale

School of #edicine, *mergenc #edicine&

A.scesses ha"e a /ide range of sonographic appearances& 6picall, the appear as anechoic orhpoechoic spherical collections of echogenic fluid /ith poorl defined .orders& Additionall,

septae, sediment, or e"en gas ma .e present /ithin the fluid collection& $ompression /ith the

transducer ma induce mo"ement or s/irling of the contained pus& See the images .elo/&



Ultrasound image of a tpical spherical a.scess&

Ultrasound image of a tpical spherical a.scess& Ultrasound image ofan a.scess& %ote the heterogenous appearance&

$ine loop of an a.scess& @ideo courtes of #eghan -ell Her.st, #D& Also courtes of ale

School of #edicine, *mergenc #edicine&

f an a.scess is identified, thorough characteri<ation of its location, si<e, and etent helps dictate

further management&

'earls

• A standoff pad ma .e useful to ele"ate the transducer, as this impro"es image resolution

. mo"ing the region of interest into the focal <one& 6his is particularl helpful /hene"aluating superficial structures such as the hands and feet& $ommercial pads can .e

purchased and customi<ed to a gi"en situation& Alternati"el, .ags of saline, /ater7filled

glo"es, or /ater .aths ma .e su.stituted&

• $olor flo/ Doppler sonograph, sho/n .elo/, is useful in identifing ad?acent "ascular

structures prior to performing an percutaneous inter"entions& 6his modalit can alsohelp identif lmph nodes, /hich can easil .e mista!en for fluid collections& mph

nodes are highl "ascular and demonstrate strong color flo/ signals, /hile a.scesses do

not& n addition, compressing lmph nodes does not result in the tpical s/irling flo/ of



fluid that is often seen /ith a.scesses& Ultrasound image

of a lmph node /ith its characteristic hperechoic center and hpoechoic rim&

Ultrasound image of a .lood "essel ling deep to a lmph node&

Ultrasound image of a lmph node demonstrating color

Doppler flo/&

• $omputed tomograph '$6( remains the criterion standard for a.scess e"aluation& $6

ma still .e necessar if the ultrasound is indeterminate or una.le to adeuatel delineatethe full etent of the a.scess&

• Herniated .o/el, sho/n .elo/, ma .e confused for an a.scess .ut can .e differentiated

. the presence of peristalsis& Ultrasound image of

herniated .o/el&





• Scanning the contralateral side of the .od for comparison is al/as helpful /hen tring

to differentiate normal tissue from a.normal tissue&

• f complicated, percutaneous inter"entions should .e ultrasound7guided to ensure proper

positioning and complete drainage&

• )ro.e co"ers can help reduce the ris! of spreading infectious agents and should .e

considered&4C, >5

"omplications

• 6he use of .edside ultrasonograph in the e"aluation of soft tissue infections presents no

apprecia.le ris!s&

'it)alls

• i!e an ultrasound stud, .e sure to consider the operators s!ill and training& Some

sonographers ha"e had more eperience than others in e"aluating and assessing soft

tissue infections&

References

1& A.rahamian B#, 6alan DA, #oran EJ& #anagement of s!in and soft7tissue infections inthe emergenc department& Infect Dis Clin North Am& #ar 200F22'1(:FG711C, "i&

4#edline5&

2& )allin DJ, *gan DJ, )elletier AJ, *spinola JA, Hooper D$, $amargo $A Jr& ncreased USemergenc department "isits for s!in and soft tissue infections, and changes in anti.iotic

choices, during the emergence of communit7associated methicillin7resistant

Staphlococcus aureus& Ann Emerg Med & #ar 200F1'3(:2G17F& 4#edline5&

3& Rogers R, )er!ins J& S!in and soft tissue infections& Prim Care& Sep 200C33'3(:CG>7>10& 4#edline5&

9& 6aal @S, Hasan %, %orton HJ, et al& 6he effect of soft7tissue ultrasound on the

management of cellulitis in the emergenc department& Acad Emerg Med & Apr

200C13'9(:3F97F& 4#edline5&

& Suire +6, Bo J$, Anderson $& A+S$*SS: applied .edside sonograph for con"eniente"aluation of superficial soft tissue infections& Acad Emerg Med & Jul 20012'>(:C017C&

4#edline5&

C& $ohen )R& $ommunit7acuired methicillin7resistant Staphlococcus aureus s!in

infections: implications for patients and practitioners& Am J Clin Dermatol &200>F'(:2G7>0& 4#edline5&

http://reference.medscape.com/medline/abstract/18295685















>& $ohen )R& $ommunit7acuired methicillin7resistant Staphlococcus aureus s!in

infections: a re"ie/ of epidemiolog, clinical features, management, and pre"ention& Int J

Dermatol & Jan 200>9C'1(:1711& 4#edline5&

F& $os. -S, -endall J& Practical Guide to Emergency Ultrasound & 1st& )hiladelphia, )a:

ippincott =illiams =il!ins 200C&



abscess evaluation using bedside ultrasonography

Documents