Evaluation of Serial Ultrasound Screening in ICU COVID-19 Patients

Background: COVID-19 has a high incidence of venous thromboembolic disease (VTE), especially pulmonary thromboembolism (PE) and deep vein thrombosis (DVT), with an even higher incidence in patients admitted to the intensive care unit (ICU). The presentation of these events is related to an increase in mortality and the mean stay in the ICU. The impact of systematic screening for asymptomatic lower extremity DVT in these patients has not been studied, so we propose to carry out a clinical trial to assess its impact in these patients.

Hypothesis: Serial DVT screening in patients admitted to the ICU for COVID-19 does not improve survival, mean stay, or the incidence of symptomatic VTE.

Objective: To study whether DVT screening in these patients has an impact on the incidence of symptomatic VTE, mortality and average stay in the ICU.

Methods: Non-blind randomized clinical trial on all patients aged 18 years or older admitted to the ICU for COVID-19 with less than 72 hours elapsed since their admission to the unit. Patients with DVT or PE will be excluded at the time of recruitment (all patients will be ruled out by routine ultrasound and computed tomography angiography (CT Angiography)); Pregnant patients, patients with a previous diagnosis of DVT or PE, and patients undergoing extracorporeal membrane oxygenation (ECMO) will also be excluded. Patients will be randomized into two arms at the time of inclusion: the screened group (Group 1) and the non-screened group (Group 2). Group 1: patients who will be treated according to the usual ICU protocol and, additionally, will undergo serial ultrasounds of the lower extremities twice a week (Monday and Thursday). Group 2: they will be treated according to the usual ICU protocol and no screening examinations will be performed. Patients will be followed until discharge from the ICU or death and up to a maximum of 3 weeks. The incidence of symptomatic VTE will be assessed, as well as all-cause mortality and days of stay in the ICU. Clinical and laboratory variables will be collected from each patient for subsequent statistical analysis.

Relevance: The thrombotic complications of COVID-19 are well described, as well as their high incidence in critically ill patients. This work aims to clarify the current doubts about the need for systematic DVT screening in these patients. If our hypothesis is verified, a limited resource such as ultrasound of the lower limbs could be saved, as well as the use of the necessary protection materials and, most importantly, avoid unnecessary exposure of health personnel with the consequent risk that it represents for other professionals and patients.

Inclusion criteria

• COVID 19 patients in their first 72 hours of entering ICU

Exclusion criteria

• Pregnant patients
• Not COVID 19 confirmed patients by RCP
• Patients that are in Extracorporeal membrane oxygenation
• Patients with previous thrombotic disease