Anticoagulation Guide for Managing PE and DVT in Critical Care

Explore guidelines on antithrombotic therapy for VTE, including PE and DVT treatment, dosing recommendations, and patient considerations.

Overview

As a critical care pharmacist, you'll often need to decide whether to start anticoagulation in patients with a high suspicion of PE or DVT. If bleeding risk is acceptable, consider starting anticoagulation before confirming the diagnosis. This can be life-saving, especially in high-risk patients.

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Management steps

For PE or proximal DVT, 3 months of anticoagulation is the standard initial treatment duration. After that, the decision is case-dependent. If the event was unprovoked and bleeding risk remains low, consider indefinite anticoagulation, especially if a D-dimer test is still positive one month after stopping treatment.

For most patients with PE or lower-extremity DVT, direct oral anticoagulants (DOACs) are preferred over warfarin for the first 3 months—think dabigatran, rivaroxaban, apixaban, or edoxaban. DOACs are simpler for patients since they don’t require frequent INR monitoring. Keep in mind, though, the choice depends on factors like bleeding risk, cost, and patient compliance.

Anticoagulant therapy

Unfractionated Heparin (UFH): Initial IV dose 80 U/kg, then 18 U/kg/hr. Target aPTT > 1.5 times control, check q6 hours until stable.
Low-Molecular-Weight Heparins (LMWH)

Enoxaparin (Lovenox, Clexane): 1 mg/kg SC q12h or 1.5 mg/kg q24 hours.
Dalteparin (Fragmin): 200 U/kg SC daily or 100 U/kg SC q12 hours.

Factor Xa inhibitors

Rivaroxaban (Xarelto): 15 mg PO BID with food for the first 3 weeks, then 20 mg PO daily.
Apixaban (Eliquis): Start with 10 mg PO BID for 7 days, then 5 mg PO BID.
Edoxaban (Savaysa): Start with a parenteral anticoagulant for 5-10 days, then 60 mg PO daily (> 60 kg) or 30 mg PO daily (≤ 60 kg).

Dabigatran (Pradaxa): Requires initial parenteral anticoagulation for 5-10 days, then switch to 150 mg PO BID (if CrCl > 30 mL/min).

Considerations

All anticoagulants have a bleeding risk. UFH and LMWH may cause heparin-induced thrombocytopenia (HIT); LMWH has a lower HIT risk. Warfarin (Marevan) is teratogenic—it’s safe for breastfeeding but avoid in pregnancy.

Pregnancy considerations

Warfarin is contraindicated in pregnancy, but LMWH (like enoxaparin or dalteparin) is recommended for DVT/PE.
Drugs like enoxaparin, dalteparin, fondaparinux, and apixaban are Category B, while dabigatran, rivaroxaban, and edoxaban fall under Category C.

Conclusion

Anticoagulation choice should be individualized—there’s no one-size-fits-all. Balance efficacy, patient convenience, and cost when selecting therapy.

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References

Kearon C, Akl EA, Ornelas J, et al. Antithrombotic Therapy for VTE Disease: CHEST Guideline and Expert Panel Report. Chest. 2016;149(2):315-352.
Ortel TL, Neumann I, Ageno W, et al. American Society of Hematology 2020 guidelines for management of venous thromboembolism: treatment of deep vein thrombosis and pulmonary embolism. Blood Adv. 2020;4(19):4693-4738.