Trauma patients at risk for venous thromboembolism who undergo routine duplex ultrasound screening experience fewer pulmonary emboli: A prospective randomized trial

Background: Although guidelines are established for the prevention and management of venous thromboembolism (VTE) in trauma, no consensus exists regarding protocols for the diagnostic approach. We hypothesized that at-risk trauma patients who undergo duplex ultrasound (DUS) surveillance for lower extremity deep venous thrombosis (DVT) will have a lower rate of symptomatic or fatal pulmonary embolism (PE) than those who do not undergo routine surveillance.

Methods: Prospective, randomized trial between March 2017 and September 2019 of trauma patients admitted to a single, level 1 trauma center, with a risk assessment profile score of ≥5. Patients were randomized to receive either bilateral lower extremity DUS surveillance on days 1, 3, and 7 and weekly during hospitalization ultrasound group (US) or no surveillance no ultrasound group (NoUS). Rates of in-hospital and 90-day DVT and PE were reported as was DVT propagation and all-cause mortality. Standard care for the prevention and management of VTE per established institutional protocols was provided to all patients.

Results: A total of 3,236 trauma service admissions were screened, and 1,989 moderate- and high-risk patients were randomized (US, 995; NoUS, 994). The mean ± SD age was 62 ± 20.1 years, Injury Severity Score was 14 ± 9.7, risk assessment profile was 7.1 ± 2.4, and 97% suffered blunt trauma. There was no difference in demographics or VTE risk factors between the groups. There were significantly fewer in-hospital PE in the US group than the NoUS group (1 [0.1%] vs. 9 [0.9%], p = 0.01). The US group experienced more in-hospital below-knee DVTs (124 [12.5%] vs. 8 [0.8%], p < 0.001) and above-knee DVTs (19 [1.9%] vs. 8 [0.8%], p = 0.05). There was no difference in 90-day PE or DVT, or overall mortality.

Conclusion: The implementation of a selective routine DUS protocol was associated with significantly fewer in-hospital PE. More DVTs were identified with routine screening; however, surveillance bias appears to exist primarily with distal DVT. Larger trials are needed to further characterize the relationship between routine DUS screening and VTE outcomes in the high-risk trauma population.

Level of evidence: Therapeutic/care management, level II.