The association of timing of pharmacological prophylaxis and venous thromboembolism in patients with moderate-to-severe traumatic brain injury: A retrospective cohort study

OBJECTIVES: Patients with traumatic brain injury (TBI) have an increased risk for venous thromboembolism (VTE). The current guidelines recommend pharmacologic prophylaxis, but its timing remains unclear. METHODS: In this retrospective cohort study, patients with moderate-to-severe TBI admitted to a tertiary care intensive care unit between 2016 and 2019 were categorized into two groups according to the timing of pharmacologic prophylaxis: early if prophylaxis was given within 72 h from hospital admission and late if after 72 h. RESULTS: Of the 322 patients in the cohort, 46 (14.3%) did not receive pharmacological prophylaxis, mainly due to early brain death; 152 (47.2%) received early pharmacologic prophylaxis and 124 (38.5%) received late prophylaxis. Predictors of late pharmacologic prophylaxis were lower body mass index, intracerebral hemorrhage (odds ratio [OR], 3.361; 95% confidence interval [CI], 1.269–8.904), hemorrhagic contusion (OR, 3.469; 95% CI, 1.039–11.576), and lower platelet count. VTE was diagnosed in 43 patients on a median of 10 days after trauma (Q1, Q3: 5, 15): 6.6% of the early prophylaxis group and 26.6% of the late group (P < 0.001). On multivariable logistic regression analysis, the predictors of VTE were Acute Physiology and Chronic Health Evaluation II score, subarachnoid hemorrhage, and late versus early pharmacologic prophylaxis (OR, 3.858; 95% CI, 1.687–8.825). The late prophylaxis group had higher rate of tracheostomy, longer duration of mechanical ventilation and stay in the hospital, lower discharge Glasgow coma scale, but similar survival, compared with the early group. CONCLUSIONS: Late prophylaxis (>72 h) was associated with higher VTE rate in patients with moderate-to-severe TBI, but not with higher mortality.