328 Incidence and Number of Missed Chemical Venous Thromboembolic Event Prophylactic Doses Predict the Development of Venous Thromboembolic Events in Traumatic Brain Injury Patients

Abstract

INTRODUCTION: Venous thromboembolic events (VTE) are a major concern in trauma and intensive care, with traumatic brain injury (TBI) patients at an elevated risk. Chemical VTE prophylaxis is used to prevent VTE development. Concerning TBI patients, achieving a fine balance between the risk of worsening hemorrhage and clot development is important. To date, there has been no correlation between the number of missed doses and VTE development in this population. METHODS: Data were retrospectively collected among 818 TBI patients admitted to a level I trauma center between 2015-2020. RESULTS: Overall VTE incidence was 9% (7.6% DVT; 3.2% PE; 1.7% both). Median time to DVT and PE was 7 (IQR: 4-11) and 5 days (IQR: 3-12), respectively. VTE occurred in 37.8% of patients who missed prophylactic doses and 28.4% who did not (p = 0.089). In patients who experienced a VTE, compared to non-VTE patients, missed chemical prophylaxis dosing was primarily due to a pending invasive procedure (44.8% vs. 25.2%, p = 0.02) and the presence of additional bleeding (13.8% vs. 2.8%, p = 0.005). Non-VTE patients missed prophylactic dosing primarily from patient or family refusal (42.1% vs. 3.4%, p < 0.001). VTE incidence was higher in patients receiving invasive neurosurgery (45.9% vs. 30.5%, p = 0.007). Univariate analysis demonstrated 4-6 total missed doses as predicting the highest VTE risk (OR 4.08, 95% CI: 1.53-10.86, p = 0.005). No VTE were seen in >7 missed doses, presumably due to an overall high mortality rate of 13.5%. CONCLUSIONS: This study is novel in showing the incidence and number of missed chemical VTE prophylaxis to predict an increased VTE risk in TBI patients. Our study suggests a threshold of 4 missed doses to be particularly important in this critical patient population.