What is the recommended approach for using heparin (unfractionated heparin (UFH) or low molecular weight heparin (LMWH)) for Deep Vein Thrombosis (DVT) prophylaxis in patients with sepsis?

Heparin for DVT Prophylaxis in Sepsis

All septic patients without contraindications should receive pharmacologic DVT prophylaxis, with LMWH preferred over unfractionated heparin due to superior efficacy and safety profile. 1

Recommended Pharmacologic Prophylaxis

First-Line: Low Molecular Weight Heparin (LMWH)

• LMWH is strongly recommended as the preferred agent over unfractionated heparin for VTE prophylaxis in septic patients 1, 2
• Standard dosing: Enoxaparin 40 mg subcutaneously once daily 1, 2
• LMWH demonstrates superior efficacy with reduced thromboembolic events (5.5% vs 14.9% with placebo) 1
• Lower risk of heparin-induced thrombocytopenia compared to UFH 1

Alternative: Unfractionated Heparin (UFH)

• Use UFH when LMWH is contraindicated, particularly in severe renal impairment (creatinine clearance <30 mL/min) 2, 3
• Dosing: 5,000 units subcutaneously either two or three times daily 1
• UFH is inexpensive and has demonstrated safety in critically ill patients 1
• Studies show mortality reduction (7.8% vs 10.9%) and decreased DVT incidence (4% vs 26%) with UFH prophylaxis 1

Absolute Contraindications to Pharmacologic Prophylaxis

When the following conditions exist, use mechanical prophylaxis instead of heparin 1:

• Active bleeding 2
• Severe thrombocytopenia 1, 2
• Severe coagulopathy 1
• Recent intracerebral hemorrhage 1, 2

Mechanical Prophylaxis

For patients with contraindications to anticoagulation, use intermittent pneumatic compression devices 1

• Mechanical devices have proven efficacy in postoperative patients and are recommended for septic patients who cannot receive heparin 1
• Graduated compression stockings may be used as an alternative if pneumatic devices are unavailable 3
• Combine mechanical with pharmacologic prophylaxis whenever possible in high-risk patients 1, 2

Special Considerations in Sepsis-Induced Coagulopathy

Septic patients present unique challenges due to consumptive coagulopathy and liver dysfunction, creating predisposition for both clotting and bleeding 1

Risk Assessment Algorithm

1. Evaluate bleeding risk daily: Check platelet count, coagulation parameters (PT/aPTT), and assess for active bleeding 4
2. If no contraindications exist: Initiate LMWH at standard prophylactic doses 1, 3
3. If severe renal impairment present: Switch to UFH or use dalteparin (renally-adjusted LMWH) 2, 3
4. If bleeding risk outweighs benefits: Use mechanical prophylaxis only and reassess daily 1, 2
5. When bleeding risk decreases: Initiate pharmacologic prophylaxis as soon as safe 3

Duration and Monitoring

• Continue prophylaxis throughout the entire hospitalization while risk factors persist 2, 3
• Monitor for signs of bleeding in patients receiving pharmacologic prophylaxis 3
• Reassess daily for both thrombotic and bleeding risk 4
• No routine coagulation monitoring is required for prophylactic-dose heparin in patients with normal baseline parameters 5

Common Pitfalls to Avoid

Do not withhold prophylaxis based solely on laboratory abnormalities without clinical bleeding 6. Septic patients frequently have abnormal coagulation tests that do not necessarily contraindicate prophylaxis 1.

Do not use antithrombin concentrate with concomitant heparin in severe sepsis, as this combination increases bleeding risk without improving mortality 7.

Avoid subcutaneous administration in patients on vasopressors or with severe peripheral edema, as bioavailability may be reduced 8, 9. Consider alternative dosing strategies or routes in these high-risk patients 9.

Do not use antifibrinolytic agents (such as tranexamic acid) in DIC associated with sepsis unless there is a primary hyperfibrinolytic state with severe bleeding 6.