Effect of a dalteparin prophylaxis protocol using anti-factor Xa concentrations on venous thromboembolism in high-risk trauma patients.

Background: Low anti-factor Xa (anti-Xa) concentrations with twice-daily enoxaparin are associated with venous thromboembolism (VTE) in high-risk trauma patients. Concerns have been raised with once-daily dalteparin regarding effectiveness and achievable anti-Xa concentrations. The purpose of this before-and-after study was to evaluate the effectiveness of a VTE prophylaxis protocol using anti-Xa concentrations and associated dalteparin dose adjustment in high-risk trauma patients.