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Dr. Alexander Butwick
MBBS, FRCA, MS
Assistant Professor in Anesthesia,
Stanford University School of Medicine
Anticoagulants and Regional
Anesthesia –
A Modern Approach
Huge topic in 25mins!!!
The Hypercoagulable State of
Pregnancy
Anticoagulation in Pregnancy 1-3
1. Venous Thromboembolism (VTE)
2. Recurrent Pregnancy Loss:
Antiphospholipid Antibodies
3. Systemic Embolism:
Mechanical Heart Valves
1. Bates SM et al. Chest 2008; 133: 844-886.
2. Duhl et al. Am J Obstet Gynecol 2007; 197:457.e1-21.
3. ACOG Practice Bulletin. Obstet Gynecol 2011; 118:718-29.
Indication LMWH or Heparin
1. Acute VTE in Pregnancy Therapeutic Doses
2. Previous VTE
- Pregnancy or estrogen-related Prophylactic Doses *
- Previous Idiopathic VTE Prophylactic Doses *
- Previous VTE + Thrombophilia Prophylactic / Intermediate Doses *
- Multiple VTEs Prophylactic / Intermediate Doses
3. Antiphospholipid Antibodies +
≥ 3 pregnancy losses
Prophylactic / Intermediate Doses
4. Long term anticoagulants Prophylactic / Intermediate Doses
CHEST 2008; 133: 844S – 886S * or clinical surveillance = no anticoagulants
Management Approaches: At-Risk Patients
Inherited Thrombophilias
• Heritable defects in the coagulation
cascade
• Anticoagulation1
– risk VTE
– ? Reduce adverse pregnancy outcomes
1. ACOG Practice Bulletin. Obstet Gynecol 2011; 117; 192 -9
VTE in pregnant women with thrombophilia
ACOG Practice Bulletin. Obstet Gynecol 2011; 117; 192 -9
Epidural Hematomas after Epidural Placement in OB patients
STUDY TYPE Epidural Hematoma
USA (Closed Claim Survey) 1 4 / 426 claims*
United Kingdom 2 0 / 320 000
Single center: Turkey 3 0 / 29 000
Meta-analysis 4 6/ 1.1 million
Sweden 5 2 /255 000
1. Davies JM et al. Anesthesiology 2009 2. Cook T et al. Brit J Anaesth 2009 3. Katiricioglu K et al. Anesth Analg 2008 4. Ruppen W. Anesthesiology 2006 5. Moen V et al. Anesthesiology 2004
* Obstetric Anesthesia Claims
Planning the Anesthetic: Stanford approach
1. Early referral & consultation with patient
2. Talk to OB ±hematology
3. Plan for ALL anesthetic possibilities for labor
and delivery
– Neuraxial block
– Non-neuraxial techniques
4. Close neurologic monitoring post-block
Decision-making: Neuraxial block & anticoagulation1
Consensus Guidelines (ASRA; European Societies)
Obstetric factors
Type of neuraxial block 1. spinal vs catheter based
2. low concentration of local
anesthetic
Anticoagulant (dosing; timing)
1. Butwick AJ, et al. Int J Obstet Anesth 2010: 19, 193–201
Guidelines for neuraxial anesthesia + anticoagulation
• Regional Anesthetic
societies:
– US (ASRA)1
– Europe (ESA)2
• Based on pharmacologic
data; expert opinion
1. Reg Anesth Pain Med 2010; 35: 64 - 101
2. Eur J Anesthesiol 2010; 27: 999 - 1015
Neuraxial anesthesia + anticoagulation
1. Heparin
2. Low Molecular Weight
Heparin
3. Fondaparinux
4. Anticoagulation during
Labor
HEPARIN
HEPARIN
• Route of administration: subcutaneous / IV
• Prophylaxis: 2-3 X / day
• Monitoring: APTT or anti-Xa level
• Side-effects:
– Heparin-induced thrombocytopenia
– Osteoporosis
– Allergic skin reactions
Heparin and Pregnancy
Barbour LA, et al. Am J Obstet Gynecol. 1995;173:1869-73.
Heparin requirements increase and are HIGHLY
VARIABLE in pregnancy
NB = Neuraxial Block; CW = Catheter withdrawal
Europe USA
Before
NB/CW
4-6 hr (15,000 U / day)
No time
interval (? 10,000 U / day
or 2 doses / day)
After
NB/CW 1 hr 1 hr
Subcutaneous Heparin and Guidelines
Stanford Approach: SC HEPARIN
No Contraindication:
Dose ≤ 5000 u / day
Duration ≤ 3 days
Wait ≥ 2 hr + PLT/APTT:
Dose > 5000 u /day
Duration > 3 days
Freq ≥ 2 doses / day
Before Block
Placement
Wait ≥ 1 hr to
restart heparin
after block
Low Molecular Weight Heparins (LMWH)
• Predictable anticoagulant response
(vs heparin)
• Fewer side-effects
LMWH and Spinal Hematoma
• 1993 - surgical thromboprophylaxis
• >58 cases of spinal hematoma (5 yr) 1
• Re-evaluation of neuraxial anesthetic practice
+ LMWH
• FDA: ‘Black box’ warning2
1. Horlocker TT et al. Reg Anesth 2003; 28: 172-197
2. Wysowski DK et al. NEJM 1998; 338: 1774-5
Europe USA
Before NB / CW 12 hr 10-12 hr
After NB / CW 4 hr
6-8 hr
(1st dose NB) /
>2 hr (CW)
NB = Neuraxial Block; CW = Catheter withdrawal
LMWH prophylaxis and guidelines
Therapeutic LMWH & guidelines
Europe USA
Before NB / CW 24 hr 24 hr
After NB / CW 4 hr
24 hr (NB)/
2 hr (CW) (twice daily
dosing)
NB = Neuraxial Block; CW = Catheter withdrawal
Heparin / LWMH & The Peripartum Period
• No clear consensus 1-3
• LMWH → Heparin @ 36 weeks
• Planned Induction of labor
– Stop heparin/LMWH : 12/24 hr before Induction
• Planned Cesarean delivery
– Stop heparin/LMWH : 12/24 hr before CS
1. Komainiarek MA et al. J Perinatol 2007; 27: 329-334
2. Maslovitz S et al. J Mat-Fet Neonat Med 2005; 17: 39-43
3. Nelson-Piercy C et al. Am J Obstet Gynecol 1997; 176: 1062-8.
Fondaparinux and Neuraxial Blocks
1. Mazzolai L et al. Blood 2006; 108: 1569-70
2. Gerhardt A et al. Thromb Haemost. 2007; 97: 496-97
3. Knol HM et al. J Thromb Haemost 2010; 8: 1876–9.
• Synthetic
pentasaccharide
• Selective factor Xa
antagonist
• Elimination half-life =
17hr
• Few reports 1-3
Fondaparinux + Neuraxial Block
Europe USA
Before NB / CW 36-42 hr -
After NB / CW 6-12 hr -
Full Anticoagulation: Labor
High Risk Patients
• ATIII deficiency
• Mechanical Heart Valves
• Acute VTE
• Coronary Stents + dual
antiplatelet therapy1
IV Heparin
Glycoprotein IIA/IIIB
inhibitors:
– Abciximab
– Eptifibatide
– Tirofiban
Full Anticoagulation
1. Bauer MEB, et al. Anesth Analg 2012;115:613–5
IV Heparin + guidelines
Europe USA
Before NB/CW 4-6 hr ? / 2-4 hr
After NB/CW 1 hr 1 hr
NB = Neuraxial Block; CW = Catheter withdrawal
Heparin Anticoagulation: Labor
Anesthetic Implications
• Discontinue heparin: 4 -6 hr before
anticipated delivery 1
• Monitor heparin effect (APTT/ TEG)
• Neuraxial block?
• Prepare for obstetric hemorrhage
– Crossmatched blood
– Reverse heparin: protamine
1. Lambert JR, et al. Br J Haematol. 2008;142: 453-6.
Summary
• Local consensus –
neuraxial blocks
• Careful
planning/timing for
neuraxial block
• Have a plan A and B
• Vigilance following
neuraxial block
– Close neurologic
assessment
Email: [email protected]