Association of prolonged emergency department length of stay and venous thrombo-embolism prophylaxis and outcomes in trauma: A nation-wide secondary analysis.

Introduction: The impact of prolonged emergency department length of stay (EDLOS) on appropriately timed pharmacological venous thromboembolism prophylaxis (VTEp) and VTE outcomes is unknown in trauma.

Methods: Retrospective cohort study of adult patients admitted to civilian trauma centers participating in the American College of Surgeons' TQIP (2019-2021). Patients with severe solid organ, head, or spine injury, early hemorrhage control intervention, pre-existing home anticoagulation or bleeding disorder, inter-facility transfer or early discharge, and injury severity score ≤9 were excluded. Primary exposure was prolonged EDLOS ≥12 h from ED arrival to physical transfer to the wards. Primary outcome was time to first pharmacological VTEp, censored at 24 and 48 h.

Results: A total of 191,031 patients were included, 3,827 remained in the ED ≥12 h. The median time to VTEp was 25 h (IQR 12-43). Prolonged EDLOS was associated with a 34 % and 21 % decrease in timely administration of VTEp at 24 (aHR 0.66, 95 % CI 0.61-0.72, P < 0.001) and 48 h (aHR 0.79, 95 % CI 0.74-0.84, P < 0.001), respectively. After propensity score matching, associations persisted at 24 (aHR 0.69, 95 % CI 0.61-0.77, P < 0.001) and 48 h (aHR 0.80, 95 % CI 0.74-0.86, P < 0.001). Absent VTEp by 24 h was associated with increased VTE odds (aOR 1.84, 95 % CI 1.62-2.08, P < 0.001).

Conclusion: Prolonged EDLOS delayed pharmacological VTEp in a nation-wide cohort of trauma patients. Absent VTEp, consequently, increased risk of in-hospital VTE, although future study is needed to validate these findings. Timely transfer of stable trauma patients to the floor may improve outcomes by facilitating appropriately timed VTEp administration and decreasing ED overcrowding.