ANTICOAGULANTS AND NEURAXIAL … HEPARIN No Contraindication: Dose ≤ 5000 u / day Duration ≤ 3 days Wait ≥ 2 hr + PLT/APTT: Dose > 5000 u /day Duration > 3 days Freq ≥ …

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]