Venous Thromboembolism Rates in Trauma Patients Significantly Increase With Missed Prophylactic Enoxaparin Doses

Background: Current literature demonstrates prophylactic enoxaparin to be efficacious in reducing venous thromboembolism (VTE) rates without significantly increasing risk for bleeding complications. Despite this evidence, prophylactic enoxaparin doses are frequently withheld for surgery or procedures. This exploratory study aims to quantify the risk of a VTE event in trauma patients associated with missed doses of prophylactic enoxaparin. Methods: This retrospective cohort study evaluated trauma patients admitted to our Level 1 trauma center from January 1, 2012 to January 31, 2021. A 1:1 propensity match with ten variables was performed to compare patients receiving prophylactic enoxaparin that had a VTE and those that did not. The primary outcome was a VTE event. Results: 493 patients met inclusion criteria; 1:1 propensity score matching was performed resulting in a cohort of 184 patients. The percentage of patients that missed a prophylactic enoxaparin dose in the VTE group was higher than the no VTE group (34.8% vs 21.7%, P = 0.049). This is consistent when examining total missed doses (P = 0.038) and consecutively missed doses (P = 0.035). The odds of having a VTE for patients that missed at least one dose or more of enoxaparin are nearly two times greater (OR 1.92, 95% CI 0.997, 3.7). Conclusion: Missing enoxaparin doses significantly increases the risk of VTE in matched populations. Most prophylactic enoxaparin doses were held for procedures, and not for bleeding events. Trauma teams should carefully weigh the risk of bleeding complications associated with continuing enoxaparin prophylaxis against the significant thromboembolic risk of withholding it.