Regional Anaesthesia and Regional Anaesthesia and ThromboprophylaxisThromboprophylaxis

Dr Kate FoggDr Kate Fogg

Royal Brompton HospitalRoyal Brompton Hospital

Regional AnaesthesiaRegional Anaesthesia

Epidural/spinalEpidural/spinalRisks/benefitsRisks/benefits

• ThromboprophylaxisThromboprophylaxiss/c heparin s/c heparin (unfractionated/LMWH)(unfractionated/LMWH)

anti-Xa or direct thrombin inhibitorsanti-Xa or direct thrombin inhibitors

antiplatelet agentsantiplatelet agentswarfarinwarfarinsystemic heparinisationsystemic heparinisation

Can you put the two together or should you stop one in order to Can you put the two together or should you stop one in order to perform the other?perform the other?

Regional blocksRegional blocks

Drug administered directly to the spinal Drug administered directly to the spinal cord to locally block afferent and efferent cord to locally block afferent and efferent nerve input.nerve input.

Usually for major thoracic, abdominal and Usually for major thoracic, abdominal and lower limb surgerylower limb surgery

Local anaesthetic +/- opiatesLocal anaesthetic +/- opiates

SpinalSpinal

Dural punctureDural punctureSingle shot usuallySingle shot usually24-26G needle, pencil point24-26G needle, pencil pointLess traumaticLess traumaticCatheter rarelyCatheter rarely

EpiduralEpidural

Larger needle – 16 GLarger needle – 16 GLoss of resistance techniqueLoss of resistance techniqueEpidural vesselsEpidural vesselsUsually a catheter techniqueUsually a catheter techniqueTrauma may be on insertion or removal of Trauma may be on insertion or removal of

cathetercatheter

BenefitsBenefits

Improved analgesia, greater mobility, Improved analgesia, greater mobility, fewer opiate side-effectsfewer opiate side-effects

Decrease stress responseDecrease stress response

adverse cardiac, pulmonary and immune adverse cardiac, pulmonary and immune outcomesoutcomes

hypercoagulable statehypercoagulable state

• Decrease troponin release in cardiac Decrease troponin release in cardiac patientspatients

• ? Does this translate into clinical benefit? Does this translate into clinical benefit

Most impressive in high-risk patients Most impressive in high-risk patients undergoing major surgeryundergoing major surgery

Decrease blood loss and transfusion requirementDecrease blood loss and transfusion requirement Decrease thromboembolic complicationsDecrease thromboembolic complications Decrease pneumonia and resp depressionDecrease pneumonia and resp depression Decrease MI and ARFDecrease MI and ARF Decrease mortalityDecrease mortality

RisksRisks

FailureFailureDural TapDural TapCatheter migration subdurallyCatheter migration subdurallyNerve damageNerve damageEpidural abscessEpidural abscessEpidural HaematomaEpidural Haematoma

HaematomaHaematoma

Rare but potentially catastrophicRare but potentially catastrophic Tryba (1993) – 1:150,000 epidural anaesthetics, Tryba (1993) – 1:150,000 epidural anaesthetics,

1:220,000 spinals 1:220,000 spinals (review 1.5 million patients) Risk probably (review 1.5 million patients) Risk probably higher if on drugs altering coagulationhigher if on drugs altering coagulation

Vandermeulen (1994) review for case reports of Vandermeulen (1994) review for case reports of haematomahaematoma

75% associated with epidural, 25% spinal75% associated with epidural, 25% spinal 87% coagulation abnormalities/technical difficulties87% coagulation abnormalities/technical difficulties Coag abnormalities include alcohol abuse, CRF, thrombocytopaenia Coag abnormalities include alcohol abuse, CRF, thrombocytopaenia

as well as drugsas well as drugs

SymptomsSymptoms

Sharp back painSharp back painNew motor/sensory lossNew motor/sensory lossUrinary retentionUrinary retentionVariable and may be confused with effect Variable and may be confused with effect

of LAof LAParaplegiaParaplegiaNeed surgery within 8 hrs to get good Need surgery within 8 hrs to get good

or partial recovery.or partial recovery.

Putting the two together?Putting the two together?

• 1993 LMWH in USA b.d unlike in Europe 1993 LMWH in USA b.d unlike in Europe o.d –sudden increase in reports of o.d –sudden increase in reports of haematoma.haematoma.

• American Society of Regional anaesthesia American Society of Regional anaesthesia and Pain Medicine – Consensus and Pain Medicine – Consensus Statement ,2002Statement ,2002

German Society of Anaesthesia and German Society of Anaesthesia and Intensive Care Medicine 2004Intensive Care Medicine 2004

Unfractionated heparinUnfractionated heparin

Vascular or cardiac casesVascular or cardiac casesAvoid if other coagulopathyAvoid if other coagulopathyHeparin delayed for 1hour after needle Heparin delayed for 1hour after needle

placementplacementCatheter removal 2-4 hr after last heparinCatheter removal 2-4 hr after last heparinPost-op monitoring for at least 48 hrsPost-op monitoring for at least 48 hrs

CardiacCardiac

Does the benefit outweigh the risk?Does the benefit outweigh the risk? Can show less troponin releaseCan show less troponin release Consistent decrease in ventilator timeConsistent decrease in ventilator time Better analgesia on day 1Better analgesia on day 1 ?fewer pulmonary complications?fewer pulmonary complications No consistent improvement in No consistent improvement in

arrythmia/cardiac/renal/neurologic outcomearrythmia/cardiac/renal/neurologic outcome No effect on mortalityNo effect on mortality

Recent case reports of haematomasRecent case reports of haematomasCan achieve other benefits with beta Can achieve other benefits with beta

blockers/multimodal analgesic techniquesblockers/multimodal analgesic techniques?only in high risk COPD patients or those ?only in high risk COPD patients or those

elderly at high risk of confusionelderly at high risk of confusion

LMWHLMWH

Dose dependent antithrombotic effect by Dose dependent antithrombotic effect by anti-Xa inhibitionanti-Xa inhibition

Anti-Xa level not predictive of bleedingAnti-Xa level not predictive of bleedingBeware antiplatelet or oral anticoagulantBeware antiplatelet or oral anticoagulantNeedle placement 10-12 hours after last Needle placement 10-12 hours after last

dose LMWHdose LMWHHigher dose….wait 24hrsHigher dose….wait 24hrs

Post-op:Post-op:Catheter technique safeCatheter technique safeB.D dosing; remove catheter beforehand. B.D dosing; remove catheter beforehand.

Wait 2hrs after catheter removal before Wait 2hrs after catheter removal before first dosefirst dose

O.D. can have indwelling catheter. O.D. can have indwelling catheter. Remove minimum of 10-12 hours after last Remove minimum of 10-12 hours after last dose. Subsequent dose minimum 2hrs dose. Subsequent dose minimum 2hrs laterlater

Oral anticoagulantsOral anticoagulants

Stop 4-5 days beforeStop 4-5 days beforePT/INR within normal limitsPT/INR within normal limits If on low dose post-op need to monitor If on low dose post-op need to monitor

INR dailyINR dailyCatheter removal when INR<1.5Catheter removal when INR<1.5

Antiplatelet medicationsAntiplatelet medications

Include: aspirin, NSAIDs, thienopyridine Include: aspirin, NSAIDs, thienopyridine derivatives (ticlodipine/clopidogrel), GP IIb/IIIa derivatives (ticlodipine/clopidogrel), GP IIb/IIIa antagonists (abciximab/tirofiban)antagonists (abciximab/tirofiban)

GPIIb/IIIa in acute coronary syndrome….unlikely to be heading for GPIIb/IIIa in acute coronary syndrome….unlikely to be heading for surgery where epidural neededsurgery where epidural needed

No wholly accepted test to guide antiplatelet No wholly accepted test to guide antiplatelet therapytherapy

CLASP study in obstetric patients – aspirin CLASP study in obstetric patients – aspirin alonealone does not increase riskdoes not increase risk

NSAID NSAID alonealone no increased risk no increased risk

Actual risk of haematoma with clopidogrel Actual risk of haematoma with clopidogrel etc unknown.etc unknown.

Based on half-lives etc…Based on half-lives etc…Stop ticlodipine 14 days, clopidogrel 7 Stop ticlodipine 14 days, clopidogrel 7

daysdaysGPIIb/IIIa contraindicated with 4 weeksGPIIb/IIIa contraindicated with 4 weeksBeware concurrent medicationsBeware concurrent medications

Little evidence increased surgical bleeding Little evidence increased surgical bleeding in non-cardiac studiesin non-cardiac studies

? Stop only to make epidural safer ? Stop only to make epidural safer (continue aspirin)(continue aspirin)

Usually on aspirin + clopidogrel because Usually on aspirin + clopidogrel because of intracoronary stentof intracoronary stent

Drug eluting stentsDrug eluting stents

Stop intimal hyperplasia which leads to early Stop intimal hyperplasia which leads to early occlusionocclusion

Delay epithelialisation – hence need long term Delay epithelialisation – hence need long term antiplatelet Rxantiplatelet Rx

Stopping antiplatelet Rx before surgery may Stopping antiplatelet Rx before surgery may increase risk of infarctincrease risk of infarct (combine hypercoagulable state+ (combine hypercoagulable state+ poorly endothelialised stent)poorly endothelialised stent)

Weigh benefit of epidural Weigh benefit of epidural (and less(and less surgical bleeding)surgical bleeding) v v ischaemia/infarctischaemia/infarct

? Combine the two ? After platelet function? Combine the two ? After platelet function

? Platelet? Plateletfunction monitoringfunction monitoring

Spectrum of response to RxSpectrum of response to RxCan we identify which patients are higher Can we identify which patients are higher

risk?risk?Bleeding timeBleeding timeOptical light transmission aggregometryOptical light transmission aggregometryPlatelet function analyserPlatelet function analyserModified TEG Modified TEG (Agarwal; Anaesthesiology 2006)(Agarwal; Anaesthesiology 2006)

Anti Xa fondaparinuxAnti Xa fondaparinux

Synthetic pentasaccharide, pure anti XaSynthetic pentasaccharide, pure anti Xa 15hr half life15hr half life Less venous thromboembolic events than with Less venous thromboembolic events than with

LMWH in orthopaedic patientsLMWH in orthopaedic patients Increased bleedingIncreased bleeding Administered post-op (6hrs)Administered post-op (6hrs) No studies with indwelling epidural cathetersNo studies with indwelling epidural catheters Haematoma risk unclearHaematoma risk unclear

Thrombin inhibitorsThrombin inhibitors

Recombinant hirudin dreivatives.Recombinant hirudin dreivatives. Inhibit free and clot bound thrombinInhibit free and clot bound thrombinArgatobatran (L arginine derivative) similar Argatobatran (L arginine derivative) similar

actionactionNo case reports spinal haematomaNo case reports spinal haematomaReports of spontaneous intracerebral Reports of spontaneous intracerebral

bleedbleedNo risk assessment statement given!No risk assessment statement given!

For each individual patient a clear drug For each individual patient a clear drug history is needed, an assessment of history is needed, an assessment of medical and surgical risk for their medical and surgical risk for their procedure, and an assessment of the procedure, and an assessment of the additional benefit of a regional anaesthetic additional benefit of a regional anaesthetic technique versus the risk of an epidural technique versus the risk of an epidural haematoma. In every patient undergoing a haematoma. In every patient undergoing a regional technique, rigorous post-op regional technique, rigorous post-op neurological monitoring is essential.neurological monitoring is essential.

Questions?Questions?