Difficult Spine: My views

Prof. Mridul M. Panditrao

ConsultantDepartment of Anesthesiology and Critical Care

Public Hospital Authority’s Rand Memorial

Hospital

Freeport, Grand Bahama,

Commonwealth of The Bahamas

“Two conditions are, therefore, absolutely necessary to produce

Spinal anesthesia:

Puncture of the Dura Mater and sub-arachnoid injection of an

anesthetic agent!”

Gaston Labat, 1922

‘Father’ of modern regional anesthesia

INTRODUCTION

Neuraxial Blockade!Historical:• James Leonard Corning: 1885; first performed neuraxial blockade (epidural) in

healthy male volunteer

• August Bier: 1899; first clinical Spinal anesthesia

• Fidel Pagés (Spanish military surgeon): 1921; "single-shot" lumbar epidural anesthesia

Spinal anesthesia has enjoyed a long history of success and has already celebrated a centennial anniversary (1999)!

INTRODUCTION

•Wulf HF: “The centennial of spinal anesthesia.” Anesthesiology 1998; 89:500–6

Neuraxial Blockade!

A well-planned, skill oriented and reasonably successful modality of anesthesia.

•Anesthesiologists master spinal anesthesia early during training: (90% technical success rate) after only 40–70 supervised attempts!!!!•However, once adequate proficiency has been achieved• It is one of the easiest techniques to perform and get adequate

results.

•Kopacz DJ, Neal JM, Pollock JE: The regional anesthesia “learning curve”: What is the minimum number of epidural and spinal blocks to reach consistency? Reg Anesth 1996; 21:182–90•Konrad C, Schupfer G, Wietlisbach M, Gerber H: “Learning manual skills in anesthesiology:” Is there a recommended number of cases for anesthetic procedures? AnesthAnalg 1998; 86:635–9

Caution!Even in expert hands, a well-executed ‘spinal block’ may ‘fail’!• It is an unusual/awkward situation• Especially, when the operator with adequate skill level encounters……..

1. Difficulty in achieving the lumbar puncture

2. Inadequate/ complete lack of free flow of the CSF

3. Inadequate block: ???? Wrong : place/ drug/ dose/ concentration/volume

One has to analyze, the exact etiology of the failure!!

•Once the avoidable causes/technical reasons have been eliminated or when it is impossible even to achieve the ‘lumbar puncture’ then it is termed as truly

“Difficult Spine!!’ Thus it is a interplay of various factors, which ultimately culminate in to

a ‘Unsuccessful/Difficult’ or ‘Inadequate/Failed spinal’

Fettes, PDW, Jansson J-R and Wildsmith JAW Failed spinal anaesthesia: mechanisms, management, and prevention. BJA 2009;102 (6): 739–48

Definitions: “Difficult Spine”:

• An anticipated or un-anticipated

• Failure of introduction of the needle

• Getting ‘wet tap’ or free flow of CSF

• Multiple attempts at lumbar puncture

• Subsequent consequences/ problems

It can be one of the etiological factors of failed spinal!

Definitions:

“Failed/Inadequate spinal”:

• In spite of • a successful lumbar puncture,• satisfactory flow of CSF and • injection of correct concentration/volume/ dose

• unanticipated, complete (failed) or • incomplete/ patchy/ lower than required level of the sub-arachnoid (or even epidural) block

Etiopathogenesis:

•Failed Spinal: If one is circumspective, about the factors involved in this

process, four set of factors need to be considered:

•Operator• Patient• Equipment•Miscellaneous

Operator factors!• Skill level/ experience & thorough knowledge of the anatomy

• more chances of failure in the hands of less experienced/ novices.

• Proficiency/ practice of the Technique: how frequently on daily basis the anesthesiologist, is performing the block?• Even in the hands of so called ‘experts’/ mature operators there can be

failure, if they have not been practicing the skill for some time in recent past• In fact this can be a major factor for these techniques falling in serious

disrepute and not being practiced, because of development of a ‘vicious cycle’.

Etiopathogenesis

Etiopathogenesis: Operator Factors

• The ‘approach’ used: • Conventionally the midline approach especially in L3-L4 interspace - The intercristal line or Tuffier’s line

• Lateral or para-median approaches, especially in heavily calcified midline ligaments• inherently more complex techniques• need again excellent knowledge of anatomy,• acquired skill and • continued practice

•Lee JA, Atkinson RS. Sir Robert Macintosh’s Lumbar Puncture and Spinal Analgesia. Edinburgh: Churchill Livingstone, 1978

Etiopathogenesis: Operator Factors

• The angle of needle insertion used • advisable to insert the needle, cephalad angle/bevel pointed upwards. • even with adequate patient position; if

Incorrect angle of

insertion and inadequate

depth of insertion

free flow of the CSF is

not achieved

‘failure’ of the block.

Etiopathogenesis

Patient factors!• Un-informed, unwilling so logically uncooperative patients will

always be a hindrance in performing a successful block.

• Use of local infiltration : reluctance to use pre-block local anesthetic infiltration, especially before sub-arachnoid block.

• The excuses which are given for this are, • ‘Anyway it is just question of one prick, so how does it matter?’• ‘Infiltration will distort the local anatomy, mask the landmarks and make my

entry more difficult.’• ‘I am quite confident/ skilled enough to do the block in first attempt, why

should I bother about additional injections?’

Etiopathogenesis: Patient Factors

No matter• what proficiency level one may be able to boast about,

• that leaving aside all the ego rides/ excuses or any issues,

• one must use the local infiltration both intradermally as well subcutaneously,

• making sure that the adequate volume/ concentration of Local anesthetic is used

• so as not to mask the landmarks, but to provide the analgesia, for the entire passage of the needle

http://www.frca.co.uk/article.aspx?articleid=100449

Etiopathogenesis

Equipment factor!• The needles:

• smaller gauge of the needle is better• A pencil-point should be used if possible. • However, in some of the elderly patients, or strong muscular adult males it is

very difficult to introduce and smoothly pass the 27 G pencil-point needle.

• The drugs: multiple factors• wrong drug, wrong concentration, wrong dose, wrong volume,• even the wrong connection between the needle and syringe, thus loss/ leaking of

the drug• Improperly stored, ineffective drug preparation• Baricity of the drug also plays a significant role in final distribution/ spread of

the drug and level, density and uniformity of the block (Non-patchyness).

Etiopathogenesis: Equipment factor!

• The adjuvants:

• the physical (precipitation/ change of pH)

• chemical (Mixture of acidic and basic drugs producing an ineffective salt)

• idiosyncratic ( The formation of a newer salt/ molecule leading to unanticipated, rarely toxic actions).

Etiopathogenesis

Miscellaneous factors: ‘Resistance to Local Anesthetics!!!!!!’• Controversial area

• Unexplainable, recurring yet unproven factors

Various proposed hypotheses • genetic predilection like redhead persons, especially females• mutation in the receptor for the action of Local anesthetics, the Sodium channels

on the nerve fibers, • pathological conditions like Ehlers Danlos syndrome• even the history of previous scorpion bite.

•Panditrao MM, Panditrao MM, Khan MI, Yadav N. Does scorpion bite lead to development of resistance to the effect of local anaesthetics? Indian J Anaesth 2012; 56:575–8.•Panditrao MM, Panditrao MM, Sunilkumar V, Panditrao AM. Can repeated scorpion bite lead to development of resistance to the effect of local anesthetics? Maybe it does! CRCM. 2013; 2, 179-82 •http://www.biomedcentral.com/1471‑2253/4/1. •Hoppe J, Popham P. Complete failure of spinal anaesthesia in obstetrics. Int J ObstetAnes 2007; 16:250-5.•Panditrao MM, Panditrao MM, V. Sunilkumar, Panditrao AM. Effect of previous scorpion bite(s) on the action of intrathecal bupivacaine: A case control study. Indian J Anaesth 2013;57:236-40.

Difficult spine• Situations are rarer

• but have a very predictable outcome ‘the failure’.

Concentrate upon the factors

• Patient factors

•Operator Factors

•Miscellaneous

Patient Factors Demographic Profile:

(a) Age: The extremes of age • Age related changes - elderly patients: calcification/ossification• Consequences of osteoporosis• Degenerative disc disease• Decreased CSF volume

(b) Sex:• Female spine - more challenges

Pronounced lordosis, More subcutaneous fat.

Patient Factors

(c) Weight:• Both underweight as well as overweight • Underweight patients - the skin &subcutaneous tissue: tougher/ loose,

due to absence of subcutaneous fat• Practically very difficult to puncture them with ‘pencil point needles’• Entry point does not remain precise, in relation with the underlying

structures, especially in midline approach• Overweight/ obese patients: Entire anatomy distorted, the skin

landmarks and the entry point are practically never well correlated with deeper structures.

(d) Height: Shorter patients - almost all the structures in the back are compressed

Patient Factors

Anatomical variations: Developmental anomalies

• Pathological processes of spine

• Kyphosis,

• Scoliosis

• epidural cysts called ‘Tarlov Cysts’

Cause difficulty in lumbar puncture as well as failed blocks.

•Hoppe J, Popham P. Complete failure of spinal anaesthesia in obstetrics. Int J ObstetAnesth 2007; 16: 250–5PophamPA.Anatomical causes of failed spinal anaesthesia may be commoner than thought. Br. J. Anaesth. 2009; 103: 459. doi:10.1093/bja/aep217

Patient Factors

Abnormalities of the spine: These truly are the causes of “Difficult Spine”

• Spinal stenosis• Osteoporotic compression fractures• Degenerative spondylolisthesis• Adult scoliosis • Degenerative disc disease• Ankylosing Spondylitis

Although many other conditions exist, most of these disorders are in fact not entirely separate entities but rather disease states along a continuum

Many of these conditions overlap in their presence and presentation in any one individual.

Operator Factors

‘Not so gentle handling of the patient’: • while positioning/keeping them still

• Anxious patient tends to be scared and un-co-operative

• sitting or lateral, the patient has to be exposed: very agitated, especially females

• If the patient has already a painful condition, for which they are on Operation table, like, lower limb fractures or intra-abdominal pathologies

Operator Factors

For adequate co-operation• very gentle and careful handling of the patient

• maximum, physical, emotional as well as moral support

• patience on part of the anesthesiologist

• avoidance of transference

• A very humane, conscientious as well as caring attitude needs to be developed.

• It would be very useful and imperative to give a combination of an anxiolytic like midazolam along with an analgesic, especially in the presence of pre-operative painful condition.

Operator Factors

Miscellaneous Factors:

• Assistance: while positioning, the role of the assistant in achieving and maintaining the patient in the correct position cannot be underestimated

• Positioning: Sitting or Lateral

Operator Factors

Positioning:Conventionally, Sitting position has lesser degree of difficulty

• midline is properly maintained• the landmarks are easier to locate• patient less likely to be rotated or laterally flexed.

• Over-enthusiastic assistants - too much forward bending of the back Space available for the needle tip’s progress hampered Correct position would be to keep the back straight

• Resultant sympathetic blockade – aggravated Enhanced gravity-induced peripheral blood pooling - significant

hypotension.

•Fredman B, Zohar E, Rislick U, Sheffer O, Jedeikin R. Intrathecalanaesthesia for the elderly patient: the influence of the induction position on peri operative haemodynamic stability and patientcomfort. Anaesth Intensive Care 2001; 29: 377-82.

Operator Factors: Positioning

Lateral position

• Elderly pre-medicated patients

• Compared to the sitting position, the lateral position may cause less hypotension.

• The identification of anatomical landmark is difficult

• May be practically very difficult to assume it, with lower limb painful pathologies like fractures/ Trauma

Prevention•Pre-operative identification/confirmation

• Thorough history taking:• Especially of any previous spine surgery, • previous difficult/ failed spinal blocks• any family history of similar instances. • The pre-operative examination• Examination of vertebral column, especially thoraco-lumbar spine, to

rule out abnormalities of spine, like kypho/scoliosis, any spinal diseases/ degenerative conditions.• If situation warrants then one may have to opt for imaging studies,

from radiological examination to CT, if required.

MANAGEMENT

“The true difficult spine is truly difficult to manage!”

• The ‘confirmed difficult spine may need mustering of all the skill, experience and knowledge,• even in terms of the team approach,• advanced equipment, • even assistance of radiological colleagues. • Plan for suitable modification• CT/ Ultra sound guided technique

• Not possible to use any one of the above techniques, then General Anesthesia

The classical examples of difficult situation are as follows:

Previous spine surgery :Spine surgery: a relative contraindication to neuraxial anesthesia.

Although it is generally accepted, as well as reported by some authors*

• Post-operative spinal stenosis and other degenerative changes

• Presence of chronic pain making the patients reluctant to allow the needle insertion.

• The post-operative anatomical changes make the insertion of needle difficult, which has to be inserted through the unfused areas.

• Evidence: it may be possible to do spinal in these patients more successfully, as compared to epidural.

But there is an increased incidence of post spinal neurological deficit.•*Harlocker TT, Wedel DJ Epidual and spinal anesthesia after a major spine surgery In Paul G. Barash, Bruce F. Cullen, Robert K. Stoelting, Michael Cahalan, M. Christine Stock. Eds.Clinical Anesthesia 6thEdn. Lippincott WilliamsWolters Kluwer Health2009;1381•Bajaj P. Regional Anaesthesia in the Patient with Pre-Existing Neurological Dysfunction. Indian J Anaesth. 2009 April; 53(2): 135–138. PMCID: PMC2900096

Pathological conditions causing severe structural changes:

• Autoimmune seronegative, painful chronic inflammatory disease of the axial skeleton

• with variable involvement of peripheral joints and nonarticular structures

• and intermittent exacerbations (‘flares’) and quiescent periods.

• Spine and sacroiliac joints (spondyloarthropathy) - eventually fusion and rigidity of the spine (‘bamboo spine’)

• Cervical spine, especially atlanto-occpital joint, Temporo-mandibular joint also affected, resulting in difficult airway management.

Ankylosing Spondylitis (AS):Bamboo Spine, Bechterew's syndrome/Marie-Strümpell disease

•http://en.wikipedia.org/wiki/Ankylosing_spondylitis,

Management: Ankylosing Spondylosis

• Difficult cases

• Insertion of needle via midline approach – impossible(Calcified Ligamentum Flavum)

• Paramedian approach

• Modifications: Taylor’s approach • L5-S1 interspace• Spinal needle inserted in a cephalo-medial direction through a skin

wheal raised 1 cm medial and 1 cm caudal to the lowermost prominence of the posterior superior iliac spine.

•Jindal P, Chopra G, Chaudhary A, Rizvi AA, and Sharma JP. Taylor's approach in an ankylosing spondylitis patient posted for percutaneous nephrolithotomy: A challenge for anesthesiologists Saudi J Anaesth. 2009 Jul-Dec; 3(2): 87–90. doi: 10.4103/1658-354X.57879. PMCID: PMC2876933•Thota RS, Sathish R, Patel R, Dewoolkar L. Taylor's approach for combined spinal epidural anesthesia in post-spine surgery: A case report. Int J Anesthesiol. 2006;10:2.

Management: Pathological Conditions

Rheumatoid Arthritis (RA):

• Generalized arthropathy• Mainly centered around the cervical spine

• Atlanto-axial as well as sub-axial joint

• General anesthesia is practically very difficult

• Recommended to try the regional techniques as the priority

• cases where the lumbar and thoracic spines are involved, in the disease process, the spinal and epidural anesthesia may be technically difficult or impossible*

• *Fombon FN, Thompson JP. Anaesthesia for the adult patient with rheumatoid arthritis. Contin Educ Anaesth Crit Care Pain (2006) 6 (6): 235-239. doi: 10.1093/bjaceaccp/mkl049

Management: Pathological Conditions

• Natural processes and conditions brought about by the general ageing & wear/tear upon the spinal discs

• The secondary effects that this has upon associated spinal structures.

• Epidural injections of local anesthetics and steroids, under image guidance.

One may try the blind technique,

but the challenges, of positioning, pain, and

complete obliteration of landmarks can lead to difficulty!

Degenerative Disc Disease (DDD):

http://www.spinal-foundation.org/Conditions/Disc-Degeneration. Degenerative Disc Disease or Disc Degeneration (Spondylosis).

Conclusion• The spinal/epidural are well established, accepted and reliable/ trust

worthy techniques

• Especially in experienced and knowledgeable hands

• In spite of celebrating the centenary, there are, instances of ‘failure’

• One has to differentiate between a ‘failure’ which in actuality may be due to an avoidable or technical causes from a ‘true difficult spine’.

Conclusion

• Meticulous, planned and multidisciplinary handling.

• The challenge is when, we come across an ‘unanticipated difficult spine’.

• In these situations, the true skill, knowledge and experience and

• most importantly, the ‘team approach are the only available weapons in the hands of anesthesiologists to overcome these challenges!!

Thank You!!