Factors Associated with Venous Thromboembolism Development in Patients with Traumatic Brain Injury

Background: Venous thromboembolic (VTE) events are a major concern in trauma and intensive care, with the pro-thrombotic state caused by traumatic brain injury (TBI) increasing the risk in affected patients. We sought to identify critical demographic and clinical variables and determine their influence on subsequent VTE development in patients with TBI. Methods: This was a cross-sectional study with data retrospectively collected from 818 patients with TBI admitted to a level I trauma center in 2015-2020 and placed on VTE prophylaxis. Results: The overall VTE incidence was 9.1% (7.6% deep vein thrombosis, 3.2% pulmonary embolism, 1.7% both). The median time to diagnosis was 7 days (interquartile range 4-11) for deep vein thrombosis and 5 days (interquartile range 3-12) for pulmonary embolism. Compared with those who did not develop VTE, patients who developed VTE were younger (44 vs. 54 years, p = 0.02), had more severe injury (Glasgow Coma Scale 7.5 vs. 14, p = 0.002, Injury Severity Score 27 vs. 21, p < 0.001), were more likely to have experienced polytrauma (55.4% vs. 34.0%, p < 0.001), more often required neurosurgical intervention (45.9% vs. 30.5%, p = 0.007), more frequently missed >= 1 dose of VTE prophylaxis (39.2% vs. 28.4%, p = 0.04), and were more likely to have had a history of VTE (14.9% vs. 6.5%, p = 0.008). Univariate analysis demonstrated that 4-6 total missed doses predicted the highest VTE risk (odds ratio 4.08, 95% confidence interval 1.53-10.86, p = 0.005). Conclusions: Our study highlights patient-specific factors that are associated with VTE development in a cohort of patients with TBI. Although many of these are unmodifiable patient characteristics, a threshold of four missed doses of chemoprophylaxis may be particularly important in this critical patient population because it can be controlled by the care team. Development of intrainstitutional protocols and tools within the electronic medical record to avoid missed doses, particularly among patients who require operative interventions, may result in decreasing the likelihood of future VTE formation.