Venous thromboembolism in transfer trauma patients: A global problem.

Background: As air travel and immobility are risk factors for venous thromboembolism, we aimed to test the hypothesis that internationally transferred trauma patients have a high incidence of venous thromboembolism on arrival.

Methods: A prospectively maintained registry of all international transferred trauma patients who presented to our level I trauma center from January 2023 to June 2024 was retrospectively reviewed. Patients with either lower extremity venous duplex ultrasound or computed tomography scan of the chest with contrast on arrival were included. The primary outcome was venous thromboembolism, either deep venous thrombosis or pulmonary embolism.

Results: There were 161 consecutive internationally transferred trauma patients; 93% had a screening venous duplex ultrasound on arrival, and 52% had a computed tomography scan of the chest with contrast. Average time from injury to arrival was 3.3 ± 4.3 days. Of those who had screening imaging, 6% had a deep venous thrombosis and 8.3% had a pulmonary embolism. Average Greenfield risk assessment profile was greater for those with than without deep venous thrombosis (10 vs 8, P = .024) and pulmonary embolism (12 vs 8, P = .001). There was no difference in days from injury or flight time for those with or without deep venous thrombosis or for those with or without pulmonary embolism.

Conclusion: To our knowledge, this is the first study to demonstrate a 6-8% incidence of venous thromboembolism on arrival in international transfer trauma patients. New protocols should include risk stratification for early thromboprophylaxis in transferring centers and screening admission venous duplex ultrasound and computed tomography scan of the chest at receiving centers.