Systematic duplex ultrasound screening in conventional units for COVID-19 patients with follow-up of 5 days

OBJECTIVE: COVID-19 patients may develop coagulopathy, which is associated with poor prognosis and high risk of thrombosis. The main objective of this work was to evaluate the prevalence of deep venous thrombosis of lower limbs (DVT) through ultrasonography in patients infected with COVID-19 admitted to conventional units at our hospital with 5 days of monitoring. The secondary objective was to determine if D-dimer levels, body mass index, and C-reactive protein were associated with DVT. METHODS: A total of 72 patients, with a mean age of 65 ± 12.3 years, infected with COVID-19 were admitted to three conventional units at our institution; 28 patients were women. A COVID-19 diagnosis was made by a transcriptase polymerase chain reaction by means of nasopharyngeal swab or by chest computer tomography without iodine contrast media. Demographics, comorbidities, and laboratory parameters were collected. A preventive anticoagulation treatment was established on admission with low-molecular-weight heparin. A complete venous duplex ultrasound (DU) test of lower limbs was performed on day (D) 0 and D5. A pulmonary computer tomography angiogram with iodine contrast media was required when pulmonary embolism was suspected. RESULTS: On D0, the DU showed acute DVT in seven patients (9.75%). A pulmonary computer tomography angiogram was performed in 12 patients (16.65%), 3 (25%) of whom had an acute pulmonary embolism. On D0, acute DVT was not significantly associated with C-reactive protein (mean 101 ± 98.6 in the group without DVT vs 67.6 ± 58.4 mg/L, P = .43) or body mass index (27.7 ± 5.04 vs 28.1 ± 2.65 kg/m(2), P = .54). However, we found a significant association between acute DVT and D-dimer levels (1536 ± 2347 vs 9652 ± 10,205 ng/mL, P < .01). Among the patients included on D0, only 32 had a DU on D5. Forty of them (55.55%) were not examined for the following reasons: 7 (9.7%) were previously diagnosed with venous thromboembolism on D0 and therefore were excluded on D5, 8 (11%) were transferred to the intensive care unit, 10 (14%) were discharged from the hospital, 5 (7%) died, and 10 (13.9%) were excluded because of technical issues. On D5, five (15.6%) patients had acute DVT in addition to those found on D0; three were distal and two proximal despite preventive anticoagulation with low-molecular-weight heparin. CONCLUSIONS: Hospitalized non-intensive care unit patients with COVID-19 pneumonia have a high frequency of venous thrombotic events justifying screening with DU.