Association of timing of initiation of pharmacologic venous thromboembolism prophylaxis with outcomes in trauma patients

BACKGROUND Patients are at a high risk for developing venous thromboembolism (VTE) following traumatic injury. We examined the relationship between timing of initiation of pharmacologic prophylaxis with VTE complications. METHODS Trauma quality collaborative data from 34 American College of Surgeons Committee on Trauma-verified levels I and II trauma centers were analyzed. Patients were excluded if they were on anticoagulant therapy at the time of injury, had hospitalization <48 hours, or received no or nonstandard pharmacologic VTE prophylaxis (heparin drip). Patient comparison groups were based on timing of initiation of VTE prophylaxis relative to hospital presentation (0 to <24 hours, 24 to <48 hours, >= 48 hours). Risk-adjusted rates of VTE events were calculated accounting for patient factors including type of pharmacologic agent in addition to standard trauma patient confounders. A sensitivity analysis was performed excluding patients who received blood in the first 4 hours and/or patients with a significant traumatic brain injury. RESULTS Within the 79,386 patients analyzed, there were 1,495 (1.9%) who experienced a VTE complication and 1,437 (1.8%) who died. After adjusting for type of prophylaxis and patient factors, the risk of a VTE event was significantly increased in the 24- to <48-hour (odds ratio, 1.26; 95% confidence interval, 1.09-1.47; p = 0.002) and >= 48-hour (odds ratio, 2.35; 95% confidence interval, 2.04-2.70; p < 0.001) cohorts relative to patients initiated at 0 to CONCLUSION Early initiation of pharmacologic VTE prophylaxis in stable trauma patients is associated with lower rates of VTE.