Characteristics of Deep Vein Thrombosis on Ultrasound in Mechanically Ventilated SARS-Cov-2 Patients

Abstract

Aim: To evaluate the prevalence of asymptomatic DVT and its characteristics on venous doppler and grey scale ultrasound in lower limbs in mechanically ventilated SARS-Cov-2 Patients with high levels of D-dimer. Methods: This cross-sectional observational study was carried out in the Department of Radiodiagnosis Sri Aurobindo Medical College and P.G. Institute, Indore over the period of one year. Doppler ultrasound (DU) was performed on critically ill SARS-COV-2 patients (n =45) with severe respiratory failure, with the diagnosis of severe pneumonia and high levels of D-dimer by bedside US examination was performed with a high-frequency linear transducer on GE-logiq E machine. DU protocol includes grayscale, colour and spectral Doppler evaluation. The examination included the deep venous system of the thigh, calf, and saphenous veins. Result: Out of Forty-five patients [age, mean age 47.1 years; female/male ratio, 0.66; DVT was diagnosed in 24 patients (53.3%), 6 (25%) in proximal venous territory femoral vein, 4 (16.66%) in popliteal veins and 14 (58.33%) in distal venous territory beneath popliteal vein. CFV diameter was increased to a mean of 13.2 mm (10.8-14.6) (normal range, 9.1-12) and PBFV reduced to a mean of 10.8 cm/s (8.1-14.5) (normal range, 21.3-49.2) on doppler in positive DVT patients. Conclusion: We propose that DU allows the detection of DVT in asymptomatic mechanically ventilated SARS-Cov-2 Patients with elevated D-dimer patients. Low resistant venous return evidenced by larger than normal CFV diameters and lower than normal PBFVs may have facilitated proximal DVT occurrence.