The epidemiology of venous thromboembolic events in a severe trauma cohort admitted to the intensive care unit of an Australian major trauma centre over a five-year period.

Abstract

Venous thromboembolism (VTE) is a major contributor to morbidity and mortality following traumatic injury. The optimal pharmacological VTE prophylaxis (VTEp) regimen is uncertain. There are limited data on VTE events and VTEp practice, particularly in the trauma population requiring admission to an intensive care unit (ICU). To describe the incidence and timing of VTE events, VTEp regimens, and associated risk factors for VTE in a severe trauma cohort requiring ICU admission. Retrospective cohort study of all trauma patients (n = 969) admitted to the ICU of the Royal Brisbane and Women's Hospital between 1/2/19 and 31/12/23. Data collected included baseline characteristics, VTEp administered, VTE investigations and outcomes including VTE events, length of stay, and mortality. Competing risks survival analysis was used to describe the association between baseline characteristics and risk of VTE development. The median injury severity score was 22 (IQR 16-29). The incidence of new VTE events, as diagnosed on imaging, within 28 days of injury was 12 %. The median time to first VTE event was 9 days (IQR 4.8-13.1), and 5 of the 121 (4 %) events occurred within 24 h of injury. In the group that were admitted within 24 h of injury, the median time to VTEp commencement was 48 h (IQR 29-71) and 74 % received unfractionated heparin as the first VTEp administered. In those that had not experienced the competing risks of death or hospital discharge, only the presence of a severe lower extremity injury (cause specific HR 1.81, 95 % CI 1.19-2.76, p= 0.005) and increasing weight (cause specific HR 1.02, 95 % CI 1.01-1.03) were associated with an increased adjusted rate of developing a VTE by day 28. Although the incidence of VTE in our cohort was lower than reported in international studies, it remains a significant burden of disease. These data can be used to inform the design of clinical trials that seek to address the evidence gaps in the optimal post-trauma VTEp regimen in the severely injured trauma population.