1.
Management of the Patient with
Suspected Perioperative Nerve Injury
@EMARIANOMD@EMARIANOMD
Edward R. Mariano, M.D., M.A.S.Edward R. Mariano, M.D., M.A.S.
Professor of Anesthesiology, Perioperative & Pain MedicineProfessor of Anesthesiology, Perioperative & Pain Medicine
Stanford University School of MedicineStanford University School of Medicine
Chief, Anesthesiology and Perioperative CareChief, Anesthesiology and Perioperative Care
Veterans Affairs Palo Alto Health Care SystemVeterans Affairs Palo Alto Health Care System

2.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
Financial DisclosuresFinancial Disclosures
 Halyard Health, B Braun – UnrestrictedHalyard Health, B Braun – Unrestricted
educational program funding paid to myeducational program funding paid to my
institutioninstitution
The contents of the following presentationThe contents of the following presentation
are solely the responsibility of the speakerare solely the responsibility of the speaker
without input from any of the abovewithout input from any of the above
companies.companies.

3.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
DisclaimerDisclaimer
 This presentation is intended forThis presentation is intended for
educational purposes only and is noteducational purposes only and is not
meant to be reproduced or redistributedmeant to be reproduced or redistributed
for commercial purposesfor commercial purposes

4.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
Learning ObjectivesLearning Objectives
 Discuss potential risks for perioperativeDiscuss potential risks for perioperative
nerve injurynerve injury
 Estimate occurrence rates of variousEstimate occurrence rates of various
regional anesthesia complicationsregional anesthesia complications
 Evaluate the patient with suspected nerveEvaluate the patient with suspected nerve
injury and recommend appropriate testinginjury and recommend appropriate testing

5.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
Incidence of ComplicationsIncidence of Complications
 SOS Regional Anesthesia Hotline ServiceSOS Regional Anesthesia Hotline Service
 10-month prospective study10-month prospective study
 Voluntary reporting:Voluntary reporting: 487487/8,150/8,150
anesthesiologists agreed to participateanesthesiologists agreed to participate
 56 major complications reported out of56 major complications reported out of
158,083 regional anesthesia procedures158,083 regional anesthesia procedures
– 78,104 central neuraxial (CNB)78,104 central neuraxial (CNB)
– 50,223 peripheral (PNB)50,223 peripheral (PNB)
Auroy Y, et al. Anesth 2002;97:1274Auroy Y, et al. Anesth 2002;97:1274

6.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
CNB Complications (Non-OB)CNB Complications (Non-OB)
CardiacCardiac
ArrestArrest
RespResp
FailureFailure
SeizureSeizure NerveNerve
InjuryInjury
DeathDeath
SpinalSpinal 2.52.5 0.60.6 0.30.3 2.52.5 0.80.8
EpiduraEpidura
ll
00 00 1.81.8 00 00
*Values expressed as n/10,000*Values expressed as n/10,000
Auroy Y, et al. Anesth 2002;97:1274Auroy Y, et al. Anesth 2002;97:1274

7.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
Spinal ComplicationsSpinal Complications
 Retrospective review of 4767 consecutiveRetrospective review of 4767 consecutive
spinal anestheticsspinal anesthetics
 Postdural puncture headache (1.3%)Postdural puncture headache (1.3%)
– 38/63 resolved with conservative treatment38/63 resolved with conservative treatment
 Persistent paresthesia (0.13%)Persistent paresthesia (0.13%)
 Infection (0.04%)Infection (0.04%)
– 2 cases: disc space infection, paraspinal2 cases: disc space infection, paraspinal
abscessabscess
Horlocker TT, et al. A&A 1997;84:578Horlocker TT, et al. A&A 1997;84:578

8.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
PNB ComplicationsPNB Complications
CardiacCardiac
ArrestArrest
RespResp
FailureFailure
SeizurSeizur
ee
NerveNerve
InjuryInjury
Interscalene (3,459)Interscalene (3,459) 00 00 00 2.92.9
Supraclav (1,899)Supraclav (1,899) 00 00 5.35.3 00
Axillary (11,024)Axillary (11,024) 00 00 0.90.9 1.81.8
Lumbar plexus (394)Lumbar plexus (394) 25.425.4 50.850.8 25.425.4 00
Femoral (10,309)Femoral (10,309) 00 00 00 2.92.9
Popliteal (952)Popliteal (952) 00 00 00 31.531.5
*Values expressed as n/10,000*Values expressed as n/10,000 Auroy Y, et al. Anesth 2002;97:1274Auroy Y, et al. Anesth 2002;97:1274

9.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
Neurologic ComplicationsNeurologic Complications
 Spinal anesthesia (n=12)Spinal anesthesia (n=12)
– 9 developed peripheral neuropathy9 developed peripheral neuropathy
– 3 developed cauda equina3 developed cauda equina
– 3/12 with sequelae > 6 mos3/12 with sequelae > 6 mos (all 3 reported(all 3 reported
paresthesia)paresthesia)
 Peripheral nerve block (n=12)Peripheral nerve block (n=12)
– 9/12 employed nerve stimulation9/12 employed nerve stimulation (3/9 reported(3/9 reported
needle current < 0.5 mA)needle current < 0.5 mA)
– 7/12 with sequelae > 6 mos7/12 with sequelae > 6 mos
Auroy Y, et al. Anesth 2002;97:1274Auroy Y, et al. Anesth 2002;97:1274

10.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
Meta-Analysis of Nerve InjuryMeta-Analysis of Nerve Injury
 Data from 32 studies (1/1/95 - 12/31/05) inData from 32 studies (1/1/95 - 12/31/05) in
adult patientsadult patients
 Rates of occurrence (any neuropathy):Rates of occurrence (any neuropathy):
– CNB = <4:10,000 orCNB = <4:10,000 or 0.04%0.04%
– PNB = <3:100 orPNB = <3:100 or 3%*3%*
 Permanent neurological injuryPermanent neurological injury
– CNB = 0-7.6:10,000CNB = 0-7.6:10,000
– PNB = insufficient data (1 case)PNB = insufficient data (1 case)
Brull R, et al. A&A 2007;104:965Brull R, et al. A&A 2007;104:965*Depends on nerve block site*Depends on nerve block site

11.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
Rates of Occurrence (Nerve Injury)Rates of Occurrence (Nerve Injury)
RateRate (per 10,000)(per 10,000)
SpinalSpinal 3.783.78
EpiduralEpidural 2.192.19
RateRate (per 100)(per 100)
InterscaleneInterscalene 2.842.84
AxillaryAxillary 1.481.48
FemoralFemoral 0.340.34
SciaticSciatic 0.410.41
Brull R, et al. A&A 2007;104:965Brull R, et al. A&A 2007;104:965

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Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
Interscalene ComplicationsInterscalene Complications
 Prospective observational study (n=520)Prospective observational study (n=520)
AcuteAcute N (%)N (%)
CNS intoxicationCNS intoxication 1 (0.2)1 (0.2)
PneumothoraxPneumothorax 1 (0.2)1 (0.2)
Non-AcuteNon-Acute N (%)N (%)
Peripheral neuropathyPeripheral neuropathy 1 (0.2)1 (0.2)
Plexus damage > 9 mosPlexus damage > 9 mos 1 (0.2)1 (0.2)
Borgeat A, et al. Anesth 2001;95:875Borgeat A, et al. Anesth 2001;95:875

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Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
Complications of Continuous PNBComplications of Continuous PNB
 1,422 consecutive1,422 consecutive
adult patientsadult patients
 8 university8 university
hospitals in Francehospitals in France
and Belgiumand Belgium
 Data collected overData collected over
1 year1 year
Capdevila X, et al. Anesth 2005;103:1035Capdevila X, et al. Anesth 2005;103:1035

14.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
Serious Adverse Events from CPNBSerious Adverse Events from CPNB
 12 direct adverse events (0.8%):12 direct adverse events (0.8%): allall
resolved without sequelaeresolved without sequelae
– Hypotension (3, all lumbar plexus)Hypotension (3, all lumbar plexus)
– Systemic toxicity (2)Systemic toxicity (2)
– Respiratory distress (4, all interscalene)Respiratory distress (4, all interscalene)
– Neuropathy (3, all FNB and 2/3 under GA)Neuropathy (3, all FNB and 2/3 under GA)
 One case of psoas muscle abscess in aOne case of psoas muscle abscess in a
diabetic: recovered with IV abx, and nodiabetic: recovered with IV abx, and no
bacteremiabacteremia
Capdevila X, et al. Anesth 2005;103:1035Capdevila X, et al. Anesth 2005;103:1035

15.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
CPNB Complications and RisksCPNB Complications and Risks
Risk FactorRisk Factor Odds Ratio (95% CI)Odds Ratio (95% CI)
NeurologicNeurologic
EventsEvents
ICU stayICU stay 9.89.8 (2.0-38.5)(2.0-38.5)
Age <40yAge <40y 3.93.9 (1.6-9.8)(1.6-9.8)
BupivacaineBupivacaine 2.72.7 (1.1-6.8)(1.1-6.8)
InfectiousInfectious
EventsEvents
Infusion >2dInfusion >2d 4.64.6 (1.6-15.9)(1.6-15.9)
Male genderMale gender 2.12.1 (1.1-4.1)(1.1-4.1)
Capdevila X, et al. Anesth 2005;103:1035Capdevila X, et al. Anesth 2005;103:1035

16.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
Mechanism of Nerve InjuryMechanism of Nerve Injury
Hadzic A, et al. RAPM 2004;29:417Hadzic A, et al. RAPM 2004;29:417
Kapur E, et al. Acta 2007;51:101Kapur E, et al. Acta 2007;51:101Selander D, et al. Acta 1977;21:182Selander D, et al. Acta 1977;21:182
IntraneuralIntraneural
Injection?Injection?
Long BevelLong Bevel
Needle 14Needle 14°°??
BevelBevel
Orientation?Orientation?
Rice AS, et al. BJA 1992;69:433Rice AS, et al. BJA 1992;69:433
Hi InjectionHi Injection
Pressure?Pressure?
30+30+
YearsYears

17.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
Bevel and OrientationBevel and Orientation
 Rabbit model: nerves impaled with 14Rabbit model: nerves impaled with 14° vs.° vs.
45° beveled needles, evaluated after 2h45° beveled needles, evaluated after 2h11
– Neuronal injury:Neuronal injury: 90%90% (14(14°°) vs. 53% () vs. 53% (45°45°))
– Injuries more severe withInjuries more severe with transversetransverse
orientation vs. parallelorientation vs. parallel
 Rat model: long- (LB) vs. short-beveledRat model: long- (LB) vs. short-beveled
(SB) needles, evaluated at 7d and 28d(SB) needles, evaluated at 7d and 28d22
– LB parallel less damaging than LB/SBLB parallel less damaging than LB/SB
transversetransverse
– SB injuries more severe at 28d vs. LBSB injuries more severe at 28d vs. LB
1. Selander D, et al. Acta 1977;21:1821. Selander D, et al. Acta 1977;21:182 2. Rice AS, et al. BJA 1992;69:4332. Rice AS, et al. BJA 1992;69:433

18.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
Intraneural InjectionIntraneural Injection
 Myth #1:Myth #1: using traditional techniques,using traditional techniques,
intraneural injection is a rare eventintraneural injection is a rare event
– 21/26 pts with paresthesia-seeking ax block21/26 pts with paresthesia-seeking ax block11
 Myth #2:Myth #2: when using a nerve stimulator, awhen using a nerve stimulator, a
twitch at > 0.5 mA = extraneuraltwitch at > 0.5 mA = extraneural
– 45% of intraneural insertions stim > 0.5 mA45% of intraneural insertions stim > 0.5 mA22
 Myth #3:Myth #3: intraneural = nerve injuryintraneural = nerve injury
– When pressure < 12 psi, recovery in 24 hWhen pressure < 12 psi, recovery in 24 h33
1. Bigeleisen PE. Anesth 2006;105:7791. Bigeleisen PE. Anesth 2006;105:779 3. Kapur E, et al. Acta 2007;51:1013. Kapur E, et al. Acta 2007;51:101
2. Chan, VWS, et al. A&A 2007;104:12812. Chan, VWS, et al. A&A 2007;104:1281

19.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
Chemical Neurotoxicity of LAChemical Neurotoxicity of LA
 IntrafascicularIntrafascicular injection worse thaninjection worse than
intraneural extrafascicular injectionintraneural extrafascicular injection11
 PerineuralPerineural injection of common LA (lido,injection of common LA (lido,
bupiv, mepiv, tetra, procaine) does notbupiv, mepiv, tetra, procaine) does not
result in axonal degenerationresult in axonal degeneration22
 Reduction in nerve blood flow withReduction in nerve blood flow with topicaltopical
lidocainelidocaine ± epinephrine± epinephrine33
– 19% (1% plain), 39% (2% plain),19% (1% plain), 39% (2% plain), 78%78% (2%(2%
with epinephrinewith epinephrine 1:200k)1:200k)33
2. Gentili F, et al. Neurosurg 1980;6:2632. Gentili F, et al. Neurosurg 1980;6:263
1. Gentili F, et al. Neurosurg 1979;4:2441. Gentili F, et al. Neurosurg 1979;4:244 3. Myers RR, et al. Anesth 1989;71:7573. Myers RR, et al. Anesth 1989;71:757

20.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
Many Contributing FactorsMany Contributing Factors
Patient:Patient: CNS disorderCNS disorder Extreme BMIExtreme BMI
MaleMale DiabetesDiabetes
AgeAge PositioningPositioning
Surgery:Surgery: Trauma/stretchTrauma/stretch BleedingBleeding
TourniquetTourniquet InfectionInfection
InflammationInflammation Cast compressionCast compression
Anesthesia:Anesthesia: LA toxicityLA toxicity VasoconstrictionVasoconstriction
PerineuralPerineural
edemaedema
Needle traumaNeedle trauma
Neal JM, et al. RAPMNeal JM, et al. RAPM

21.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
Nerve Injury and “Double Crush”Nerve Injury and “Double Crush”
 Theory: preexisting nerve lesions mayTheory: preexisting nerve lesions may
predispose nerve to further injurypredispose nerve to further injury11
 Nerve block-induced injury = 2Nerve block-induced injury = 2ndnd
crush?crush?
– Case reports: ISB and cisplatin-inducedCase reports: ISB and cisplatin-induced
neurotoxicityneurotoxicity22
and multiple sclerosisand multiple sclerosis33
– Retrospective review: 2/567 pts withRetrospective review: 2/567 pts with
preexisting neuropathy had progressivepreexisting neuropathy had progressive
symptoms after CNBsymptoms after CNB44
 Clinical evidence not conclusiveClinical evidence not conclusive
1. Upton AR, et al. Lancet 1973;2:3591. Upton AR, et al. Lancet 1973;2:359
2. Hebl JR, et al. A&A 2001;92:2492. Hebl JR, et al. A&A 2001;92:249
3. Koff MD, et al. Anesth 2008;108:3253. Koff MD, et al. Anesth 2008;108:325
4. Hebl JR, et al. A&A 2006;103:12944. Hebl JR, et al. A&A 2006;103:1294

22.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
What Do You Tell Patients?What Do You Tell Patients?
 Discuss benefitsDiscuss benefits
 Discuss risksDiscuss risks
– BleedingBleeding
– InfectionInfection
– Nerve injuryNerve injury
 Incidence of nerve injury not clear:Incidence of nerve injury not clear:
1/41851/4185 – 3/100– 3/1001-31-3
 Select patients and surgeons carefullySelect patients and surgeons carefully
1. Auroy Y, et al. Anesth 2002;97:12741. Auroy Y, et al. Anesth 2002;97:1274 2. Brull R, et al. A&A 2007;104:9652. Brull R, et al. A&A 2007;104:965
3. Barrington MJ, et al. RAPM 2009;34:5343. Barrington MJ, et al. RAPM 2009;34:534

23.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
Diagnosis of Nerve InjuryDiagnosis of Nerve Injury
 Meticulous patient follow-up is essentialMeticulous patient follow-up is essential
 Single-injection nerve blocks: callSingle-injection nerve blocks: call
outpatients or visit inpatientsoutpatients or visit inpatients
– Assess for recovery of gross sensation andAssess for recovery of gross sensation and
motor functionmotor function
– Evaluate areas of residual block vs.Evaluate areas of residual block vs.
neurologic deficit by physical examneurologic deficit by physical exam
 Continuous catheters: daily phone call orContinuous catheters: daily phone call or
inpatient visitinpatient visit
Ilfeld BM, et al. RAPM 2003;28:418Ilfeld BM, et al. RAPM 2003;28:418

24.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
If Nerve Injury is Suspected…If Nerve Injury is Suspected…
 Review procedureReview procedure
documentationdocumentation
 Perform careful physical exam toPerform careful physical exam to
assess affected areas and levelassess affected areas and level
of lesionof lesion
 Consider early NeurologistConsider early Neurologist
consultationconsultation
 If compressive hematomaIf compressive hematoma
suspected, evaluate with MRI/CTsuspected, evaluate with MRI/CT
Borgeat A. Minerva Anes 2005;71:353Borgeat A. Minerva Anes 2005;71:353

25.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
Electrophysiological TestingElectrophysiological Testing
 Electromyography (EMG):Electromyography (EMG): employs needleemploys needle
electrode into muscleelectrode into muscle
– Identify injury pattern (fibrillation, abnormalIdentify injury pattern (fibrillation, abnormal
discharges or recruitment pattern)discharges or recruitment pattern)
– May help determineMay help determine chronicitychronicity of injury: acuteof injury: acute
vs. preexistingvs. preexisting
 Nerve Conduction Study (NCS):Nerve Conduction Study (NCS): measuresmeasures
velocity, latency, and amplitude forvelocity, latency, and amplitude for
peripheral nerves, may identifyperipheral nerves, may identify focal lesionfocal lesion
Borgeat A. Minerva Anes 2005;71:353Borgeat A. Minerva Anes 2005;71:353Mayfield JB. Anes Clin 2005;43:119Mayfield JB. Anes Clin 2005;43:119

26.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
Classification of Nerve InjuryClassification of Nerve Injury
 Neuropraxia:Neuropraxia: mild insult resulting frommild insult resulting from
impulse conduction failureimpulse conduction failure
– EMG normal, NCS decreased velocity and/orEMG normal, NCS decreased velocity and/or
increased latenciesincreased latencies
 Axonotmesis:Axonotmesis: axonal disruption withaxonal disruption with
connective tissue intactconnective tissue intact
– EMG and NCS abnormalEMG and NCS abnormal
– Neural regeneration occurs (1-3 mm/day)Neural regeneration occurs (1-3 mm/day)
 Neurotmesis:Neurotmesis: complete disruption, poorcomplete disruption, poor
prognosisprognosis
Borgeat A. Minerva Anes 2005;71:353Borgeat A. Minerva Anes 2005;71:353

27.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
Testing RecommendationsTesting Recommendations
 EMG/NCS in 1-3 days toEMG/NCS in 1-3 days to
assess chronicity of injuryassess chronicity of injury
 If EMG normal, repeat in 3-4If EMG normal, repeat in 3-4
weeksweeks
 If either test abnormal,If either test abnormal,
repeat in 6 monthsrepeat in 6 months
 Serial studies generally notSerial studies generally not
necessary—follow progressnecessary—follow progress
clinicallyclinically
Borgeat A. Minerva Anes 2005;71:353Borgeat A. Minerva Anes 2005;71:353Mayfield JB. Anes Clin 2005;43:119Mayfield JB. Anes Clin 2005;43:119

28.
Managing Perioperative Nerve InjuryManaging Perioperative Nerve Injury
SummarySummary
 We discussed potential risks forWe discussed potential risks for
perioperative nerve injuryperioperative nerve injury
 We estimated occurrence rates of variousWe estimated occurrence rates of various
regional anesthesia complicationsregional anesthesia complications
 We discussed how to evaluate the patientWe discussed how to evaluate the patient
with suspected nerve injury andwith suspected nerve injury and
recommend appropriate testingrecommend appropriate testing