Prevention of thromboembolism after spinal cord injury using low-molecular-weight heparin

Objective: To examine the safety and effectiveness of a low-molecular-weight heparin in the prevention of thromboembolism in patients with recent spinal cord injury and complete motor paralysis. Design: Randomized evaluation of two heparin regimens in 41 consecutive patients meeting eligibility requirements for anticoagulant prophylaxis. Daily bedside examinations were supplemented by serial venous flow studies; suspicious or positive tests were confirmed by venography. Intervention: Standard heparin, 5000 units subcutaneously three times a day; low-molecular-weight heparin 3500 anti-Xa units subcutaneously once daily. Measurements and Main Results: Five patients in the standard heparin group had thrombotic events, including two patients with fatal pulmonary embolism; two other patients had bleeding severe enough to necessitate withdrawing the heparin. The cumulative event rate was 34.7% (95% CI, 13.7% to 55.2%). None of the patients treated with low-molecular-weight heparin had thrombosis or bleeding (CI, 0% to 14%). The difference between the two groups was significant (P = 0.006, log-rank test). Conclusions: Low-molecular-weight heparin is safe and effective in the prevention of thromboembolism in selected patients with spinal cord injury and complete motor paralysis, and is superior to standard heparin in fixed doses of 5000 units three times a day.