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.