Regional Anesthetics and Anticoagulation

Regional Anesthetics Regional Anesthetics and Anticoagulationand Anticoagulation

ObjectivesObjectives

Coagulation CascadeCoagulation Cascade Thromboembolic Disorders During Thromboembolic Disorders During

PregnancyPregnancy Guidelines for regional anesthetics Guidelines for regional anesthetics

and anticogulationand anticogulation

Coagulation CascadeCoagulation Cascade

Conditions Warranting Conditions Warranting Anticoagulation During PregnancyAnticoagulation During Pregnancy

Mechanical prosthetic valve Mechanical prosthetic valve Inherited deficiency of naturally occuring Inherited deficiency of naturally occuring

anticoagulant: anticoagulant: • Factor V Leiden Factor V Leiden • Protein C deficiency Protein C deficiency • Protein S deficiency Protein S deficiency • Antithrombin III deficiency Antithrombin III deficiency

Prior episode of venous thromboembolismPrior episode of venous thromboembolism Acute deep venous thrombosis or pulmonary Acute deep venous thrombosis or pulmonary

embolism during pregnancy embolism during pregnancy Antiphospholipid antibody syndrome Antiphospholipid antibody syndrome

Mechanical Prosthetic ValvesMechanical Prosthetic Valves

Pregnant women with a prosthetic valve Pregnant women with a prosthetic valve are at high risk for thromboembolic are at high risk for thromboembolic phenomena, valve failure and bacterial phenomena, valve failure and bacterial endocarditis.endocarditis.

Complications from anticoagulation Complications from anticoagulation include fetal teratogenicity, and maternal include fetal teratogenicity, and maternal and fetal hemorrhageand fetal hemorrhage

All pregnant women with a prosthetic All pregnant women with a prosthetic valve require anticoagulationvalve require anticoagulation


Warfarin crosses the placenta and Warfarin crosses the placenta and has been associated with fetal has been associated with fetal malformations and hemorrhage.malformations and hemorrhage.

The teratogenic effects of warfarin The teratogenic effects of warfarin are limited to the first trimester. It are limited to the first trimester. It may be used in the second and third may be used in the second and third trimester, but must be discontinued trimester, but must be discontinued prior to delivery.prior to delivery.


Heparin does not cross the placenta, Heparin does not cross the placenta, but can still cause maternal but can still cause maternal hemorrhage.hemorrhage.

Low molecular weight heparin has Low molecular weight heparin has also been used safely in pregnancy also been used safely in pregnancy as it does not cross the placenta.as it does not cross the placenta.

Factor V LeidenFactor V Leiden

Factor V Leiden is a mutated form of Factor V Leiden is a mutated form of Factor V that is resistant to the Factor V that is resistant to the effects of activated protein Ceffects of activated protein C

Patients with FVL are at increased Patients with FVL are at increased risk for deep vein thrombosis.risk for deep vein thrombosis.

Women with FVL are treated with Women with FVL are treated with heparin during pregnancy.heparin during pregnancy.

Protein C DeficiencyProtein C Deficiency Protein C is produced in the liver, requires Protein C is produced in the liver, requires

Vitamin K for synthesisVitamin K for synthesis It acts by inhibiting activated factors V and VIIIIt acts by inhibiting activated factors V and VIII Incidence – 1:15,000Incidence – 1:15,000 Levels of Protein C normally increase by 35% in Levels of Protein C normally increase by 35% in

pregnancypregnancy In patients with Protein C deficiency, thrombosis In patients with Protein C deficiency, thrombosis

occurs in 25% of pregnancies, unless occurs in 25% of pregnancies, unless anticoagulation is administered.anticoagulation is administered.

Heparin is administered during the 1Heparin is administered during the 1stst and 3 and 3rdrd trimesters and heparin or warfarin during 2trimesters and heparin or warfarin during 2ndnd trimester and post-partum.trimester and post-partum.

Protein S DeficiencyProtein S Deficiency

Protein S is produced by the liver and Protein S is produced by the liver and requires Vitamin K for synthesisrequires Vitamin K for synthesis

Protein S is a cofactor for Protein CProtein S is a cofactor for Protein C The levels of Protein S normally The levels of Protein S normally

decrease during pregnancydecrease during pregnancy Heparin is administered in the 1Heparin is administered in the 1stst and and

33rdrd trimester and warfarin or heparin trimester and warfarin or heparin during the 2during the 2ndnd trimester and trimester and postpartumpostpartum

Antithrombin III DeficiencyAntithrombin III Deficiency Synthesized by liver and endothelial cellsSynthesized by liver and endothelial cells It inactivates thrombin and factors IXa, Xa, It inactivates thrombin and factors IXa, Xa,

XIa and XIIa.XIa and XIIa. Incidence – 1:5000Incidence – 1:5000 Risk of thrombosis iin pregnancy is 55% – Risk of thrombosis iin pregnancy is 55% –

68% in untreated patients.68% in untreated patients. Anticoagulation or antithrombin III Anticoagulation or antithrombin III

replacement is required in pregnancyreplacement is required in pregnancy Heparin during 1Heparin during 1stst and 3 and 3rdrd trimester and trimester and

heparin or warfarin during he 2heparin or warfarin during he 2ndnd trimester trimester and postpartumand postpartum

Venous ThromboembolismVenous Thromboembolism Includes Deep Vein Thrombosis (DVT) and Includes Deep Vein Thrombosis (DVT) and

Pulmonary Embolism (PE)Pulmonary Embolism (PE) Incidence of DVT - 0.02% to 0.36% of all Incidence of DVT - 0.02% to 0.36% of all

pregnanciespregnancies Incidence of PE - 0.05% of all pregnanciesIncidence of PE - 0.05% of all pregnancies Treatment options should take the Treatment options should take the

following into consideration:following into consideration:• (1) the safety of the drug for both the fetus and (1) the safety of the drug for both the fetus and

mothermother• (2) the efficacy of the regimen(2) the efficacy of the regimen• (3) dose regimens for acute and secondary (3) dose regimens for acute and secondary

treatment and during delivery and after treatment and during delivery and after childbirth. childbirth.

Venous ThromboembolismVenous Thromboembolism

Patients can be effectively treated with Patients can be effectively treated with Heparin or LMWH. Heparin or LMWH.

Warfarin should only be used in the 2Warfarin should only be used in the 2ndnd trimester or during the postpartum period.trimester or during the postpartum period.

Heparin and LMWH should be discontinued Heparin and LMWH should be discontinued 24 hours prior to elective induction of 24 hours prior to elective induction of labor to avoid an unwanted anticoagulant labor to avoid an unwanted anticoagulant effect during delivery.effect during delivery.


Postpartum heparin therapy should Postpartum heparin therapy should be restarted within 12 hours of be restarted within 12 hours of delivery. delivery.

Warfarin can be started at the same Warfarin can be started at the same time with a goal INR of 2.0 or time with a goal INR of 2.0 or greater. greater.


Anticoagulants should be given for at least Anticoagulants should be given for at least 4 weeks following delivery.4 weeks following delivery.

If the DVT or PE was diagnosed during If the DVT or PE was diagnosed during pregnancy, anticoagulants should be pregnancy, anticoagulants should be continued for a minimum of 3 months.continued for a minimum of 3 months.

Inferior vena cava filters are indicated in Inferior vena cava filters are indicated in patients with a contraindication to patients with a contraindication to anticoagulants.anticoagulants.

Antiphospholipid SyndromeAntiphospholipid Syndrome Presence of 2 autoantibodies, lupus antioagulant Presence of 2 autoantibodies, lupus antioagulant

and anticardiolopin antibodyand anticardiolopin antibody Patients are at risk for venous and arterial Patients are at risk for venous and arterial

thrombotic eventsthrombotic events Mechanism is unknown but related to enhanced Mechanism is unknown but related to enhanced

platelet activity, inhibition of protein C and platelet activity, inhibition of protein C and elevated factor VIII activityelevated factor VIII activity

Fetus at high risk for death in utero due to Fetus at high risk for death in utero due to placental infarctionplacental infarction

Studies have showed improved fetal outcome Studies have showed improved fetal outcome when affected pregnant women are treated with when affected pregnant women are treated with prednisone, heparin or aspirin.prednisone, heparin or aspirin.

Guidelines for Regional Anesthesia Guidelines for Regional Anesthesia while on Anticoagulationwhile on Anticoagulation

Subcutaneous HeparinSubcutaneous Heparin Intravenous HeparinIntravenous Heparin Low Molecular Weight HeparinLow Molecular Weight Heparin CoumadinCoumadin Antiplatelet MedicationsAntiplatelet Medications

Subcutaneous HeparinSubcutaneous Heparin

During administration of During administration of subcutaneous heparin, there is no subcutaneous heparin, there is no contraindication to neuroaxial contraindication to neuroaxial techniquestechniques

For patients receiving mini dose For patients receiving mini dose heparin for ≥ 4 days, reassess heparin for ≥ 4 days, reassess platelet count prior to neuroaxial platelet count prior to neuroaxial block or removal of catheter.block or removal of catheter.

Intravenous HeparinIntravenous Heparin

Should be avoided in patients with Should be avoided in patients with concomitant coagulopathiesconcomitant coagulopathies

Heparin administration should be Heparin administration should be delayed for 1 hour after needle delayed for 1 hour after needle placement placement

Intravenous HeparinIntravenous Heparin

Indwelling neuraxial catheters should Indwelling neuraxial catheters should be removed 2-4 hours after the last be removed 2-4 hours after the last heparin dose and reevaluation of the heparin dose and reevaluation of the patient's coagulation status has patient's coagulation status has occurred.occurred.

Re-heparinization should occur one Re-heparinization should occur one hour after catheter removal. hour after catheter removal.

Low-Molecular Weight Heparin (LMWH)Low-Molecular Weight Heparin (LMWH)

Monitoring of anti-Xa level is not Monitoring of anti-Xa level is not recommended as it is not predictive of the recommended as it is not predictive of the risk of bleeding.risk of bleeding.

Antiplatelet or oral anticoagulant Antiplatelet or oral anticoagulant medications administered in combination medications administered in combination with LMWH may increase the risk of spinal with LMWH may increase the risk of spinal hematoma. hematoma.

Traumatic needle or catheter placement may Traumatic needle or catheter placement may signify an increased risk of spinal hematoma signify an increased risk of spinal hematoma and initiation of LMWH therapy in this setting and initiation of LMWH therapy in this setting should be delayed for 24 hours.should be delayed for 24 hours.


In patients receiving LMWH for DVT In patients receiving LMWH for DVT prophylaxis prior to surgery, needle prophylaxis prior to surgery, needle placement should be delayed at least placement should be delayed at least 10-12 hours after the administration 10-12 hours after the administration of LMWH.of LMWH.


In patients receiving higher doses of In patients receiving higher doses of LMWH (1 mg/kg every 12 hours or LMWH (1 mg/kg every 12 hours or 1.5 mg/kg daily), needle insertion 1.5 mg/kg daily), needle insertion should be delayed for 24 hours.should be delayed for 24 hours.

Low-Molecular Weight Heparin (LMWH)Low-Molecular Weight Heparin (LMWH)Twice daily dosingTwice daily dosing

The first dose of LMWH should be started no The first dose of LMWH should be started no earlier than 24 hours postoperatively and earlier than 24 hours postoperatively and surgical hemostasis has been achieved. surgical hemostasis has been achieved.

Indwelling catheters should be removed prior to Indwelling catheters should be removed prior to initiation of LMWH thromboprophylaxis. initiation of LMWH thromboprophylaxis.

If a continuous technique is selected, the If a continuous technique is selected, the epidural catheter may be left indwelling epidural catheter may be left indwelling overnight and removed the following day, with overnight and removed the following day, with initiation of LMWH occurring at least two hours initiation of LMWH occurring at least two hours after catheter removal. after catheter removal.

Low-Molecular Weight Heparin (LMWH)Low-Molecular Weight Heparin (LMWH)Single daily dosingSingle daily dosing

The first postoperative LMWH dose should be The first postoperative LMWH dose should be administered 6-8 hours postoperatively and administered 6-8 hours postoperatively and the second dose should be given at least 24 the second dose should be given at least 24 hours after the first dose. hours after the first dose.

Indwelling catheter should be removed at Indwelling catheter should be removed at least 10-12 hours after the last dose of least 10-12 hours after the last dose of LMWH. LMWH.

Further LMWH dosing should occur ≥ 2 hours Further LMWH dosing should occur ≥ 2 hours after catheter removal. after catheter removal.

WarfarinWarfarin In patient’s receiving chronic In patient’s receiving chronic

anticoagulation, warfarin should be anticoagulation, warfarin should be discontinued at least 4-5 days before discontinued at least 4-5 days before procedure.procedure.

The PT/INR should be evaluated prior to The PT/INR should be evaluated prior to any neuroaxial technique.any neuroaxial technique.

In patients with an epidural receiving low In patients with an epidural receiving low dose warfarin therapy, the PT/INR should dose warfarin therapy, the PT/INR should be monitored on a daily basis, and be monitored on a daily basis, and checked before catheter removal.checked before catheter removal.

WarfarinWarfarin Indwelling catheters can be removed when Indwelling catheters can be removed when

the INR is less 1.5the INR is less 1.5

In patient’s with an INR >3, the warfarin In patient’s with an INR >3, the warfarin dose should be held or decreased. dose should be held or decreased. • No definitive recommendation for removal of No definitive recommendation for removal of

neuraxial catheters in patients with therapeutic neuraxial catheters in patients with therapeutic levels of anticoagulation.levels of anticoagulation.

Neurologic testing should be performed Neurologic testing should be performed routinely during epidural analgesia and routinely during epidural analgesia and should be continued after catheter should be continued after catheter removal for at least 24 hours. removal for at least 24 hours.

Antiplatelet MedicationsAntiplatelet Medications

NSAIDs, NSAIDs, Thienopyridine derivativesThienopyridine derivatives

• Ticlopidine and ClopidogrelTiclopidine and Clopidogrel Platelet GP IIb/IIIa antagonistsPlatelet GP IIb/IIIa antagonists

• Abciximab, Eptifibatide and Tirofiban Abciximab, Eptifibatide and Tirofiban

Antiplatelet MedicationsAntiplatelet Medications NSAIDs do not represent added significant NSAIDs do not represent added significant

risk for the development of spinal risk for the development of spinal hematoma in patients having epidural or hematoma in patients having epidural or spinal anesthesia.spinal anesthesia.

The actual risk of spinal hematoma with The actual risk of spinal hematoma with ticlopidine and clopidogrel and the GP ticlopidine and clopidogrel and the GP IIb/IIIa antagonists is unknown IIb/IIIa antagonists is unknown • The suggested time interval between The suggested time interval between

discontinuation of thienopyridine therapy and discontinuation of thienopyridine therapy and neuraxial blockade is 14 days for ticlopidine neuraxial blockade is 14 days for ticlopidine and 7 days for clopidogrel. and 7 days for clopidogrel.

Antiplatelet MedicationsAntiplatelet Medications

GP IIb/IIIa inhibitors exert a profound GP IIb/IIIa inhibitors exert a profound effect on platelet aggregation. effect on platelet aggregation.

Platelet aggregation returns to normal Platelet aggregation returns to normal after 24-48 hours for abciximab and 4-8 after 24-48 hours for abciximab and 4-8 hours for eptifibatide and tirofiban.hours for eptifibatide and tirofiban.

Neuraxial techniques should be avoided Neuraxial techniques should be avoided

until platelet function has recovered. until platelet function has recovered.

ConclusionsConclusions

The decision to perform spinal or epidural The decision to perform spinal or epidural anesthesia/analgesia and the timing of anesthesia/analgesia and the timing of catheter removal in a patient receiving catheter removal in a patient receiving anticoagulation should be made on an anticoagulation should be made on an individual basis.individual basis.

The patient's coagulation status should be The patient's coagulation status should be optimized at the time of spinal or epidural optimized at the time of spinal or epidural needle/catheter placement.needle/catheter placement.

ConclusionsConclusions

The level of anticoagulation must be The level of anticoagulation must be carefully monitored during the period carefully monitored during the period of epidural catheterization. of epidural catheterization.

Indwelling catheters should not be Indwelling catheters should not be removed in the presence of removed in the presence of therapeutic anticoagulation.therapeutic anticoagulation.

Documents

Regional Anesthetics and Anticoagulation