Systematic Ultrasound Screening for Lower Extremity Deep Vein Thrombosis in ICU Patients with Severe COVID-19: A Randomized Clinical Trial.

Background: Venous thromboembolism (VTE), whether pulmonary embolism (PE) or deep vein thrombosis (DVT), is common in patients with COVID-19. Recommendations on systematic screening in the intensive care unit (ICU) are lacking.

Research Question: Is there any clinical benefit of systematic screening for DVT in critically ill patients with severe COVID-19?

Study Design And Methods: Single-center randomized clinical trial (RCT) of COVID-19 cases admitted to the ICU. Patients were randomized into two groups: a study group that underwent ultrasound (US) screening for DVT Mondays and Thursdays, and a control group that was treated according to the unit protocol. The primary outcome was the presence of DVT. Secondary outcomes were ICU total stay, death within 21-day follow-up and bleeding complications (minor or major). A composite outcome of poor prognosis variables was analyzed. We tested a superiority hypothesis with a confidence level of 95% and an equivalence limit of 20%.

Results: 163 patients (84 screening group, 79 control group) were enrolled between April and July 2021. There were 90 men (55.2%) with a mean ± SD age of 49.8 ± 13.58 years. In screening group 16.7% developed DVT versus 3.8% in control group (p = .007), and 3.6% versus 5.1% developed PE, respectively (p = 0.7). Poor outcome variables were male sex, age, COVID-19 vaccination status, Fibrinogen, Urea, Creatinine and Interleukin 6 (IL6) levels; Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment (SOFA) scales. The superiority comparison, with a power of 95%, showed no statistically significant differences for a composite endpoint (p = .123). After adjusting by group, the OR for poor outcome is 1.966 (0.761-5.081) p = 0.163.

Interpretation: Among these patients, a strategy of systematic US screening for DVT was not associated with any significant improvements to clinical outcomes compared with usual care.

Clinical Trial Registration: Clinicaltrials.org registration number: NCT05028244.