Delayed prophylaxis with unfractionated heparin increases the risk of venous thromboembolic events in patients with moderate to severe traumatic brain injury: a retrospective analysis

Background
Venous thromboembolism (VTE) is a recognized complication in patients with traumatic brain injury (TBI) and is associated with increased morbidity and mortality. Currently, no standard exists for optimal timing or a pharmacological agent for VTE prophylaxis (pharmacological thromboprophylaxis – PTP) in patients with TBI. PTP is often delayed out of fear of causing extension of intracranial hemorrhage (ICH). The purpose of this study was to report the frequency of VTE and ICH progression after initiation of PTP with a continuous infusion of unfractionated heparin in patients with moderate to severe TBI, and to identify risk factors associated with development of VTE.

Methods
In this single-center retrospective study, patients with moderate to severe TBI admitted to the ICU of a Swiss Level I Trauma Center over a three-year period were analyzed.

Results
In 23 (13%) of the 177 patients included in the study a VTE episode occurred during the hospital stay. ICH progression after initiation of PTP occurred in 7 (4%) patients. In a multivariable logistic regression model, only the timing of initiation of PTP was identified as an independent predictor of VTE.

Conclusions
In this study population, the risk of developing VTE increased with the delay of initiation of a pharmacological VTE prophylaxis, while ICH progression after initiation of PTP was a rare event.