Daily vs twice daily enoxaparin in the prevention of venous thromboembolic disorders during rehabilitation following acute spinal cord injury

Background: Subcutaneous administration of low molecular weight heparin (eg, enoxaparin) has been shown to be safe and effective in the prevention of acute venous thromboembolic (TE) disease following acute spinal cord injury (SCI) in the rehabilitation setting. However, emerging evidence suggests that different dosing strategies may be equivalent. Objective: To determine whether subcutaneous enoxaparin, 40 mg once daily, when compared with subcutaneous enoxaparin, 30 mg twice daily, is equally safe and effective in the prevention of venous TE disease in patients with SCI. Design: Retrospective chart review. Setting: A freestanding, inpatient, acute, rehabilitation hospital. Patients: One hundred and twenty-nine patients admitted from June 2000 through June 2002 for inpatient rehabilitation following an acute SCI who received either enoxaparin, 40 mg once daily, or enoxaparin, 30 mg twice daily, for prophylaxis for TE disease. Results: Equivalent prophylaxis efficacy was seen in both enoxaparin groups. Symptomatic venous thromboembolism did not differ, with deep vein thromboses occurring in 1 of 49 (2.0%) patients receiving twice-daily enoxaparin, and 1 of 80 (1.25%) patients receiving once-daily enoxaparin (chi(2) = 0.125, NS). Pulmonary embolism was seen in 1 of 49 (2.0%) patients treated with twice-daily enoxaparin and in none of the patients in the once-daily group (chi(2) = 1.64, NS). Bleeding complications also did not differ between the 2 treatment groups; these were observed in 2 of 49 (4.1%) patients receiving twice-daily enoxaparin and in 5 of 80 (6.3%) patients receiving once-daily enoxaparin (chi(2) = 0.228, NS). Conclusion: Subcutaneous enoxaparin administered once or twice daily is equally effective for the prevention of venous TE disease. Both dosing strategies are associated with a low incidence of bleeding in patients with SCI who are undergoing rehabilitation.