Low incidence of deep vein thrombosis in critically ill medical patients in Thais: a prospective study.

Background: Critically ill medical patients face a heightened risk of developing venous thromboembolism. In Thailand, routine thromboprophylaxis is not employed. The incidence of deep vein thrombosis (DVT) in the medical intensive care unit (ICU) has not been elucidated in the Thai population. Objectives: The aims were to evaluate the incidence of DVT and identify associated risk factors in critically ill medical patients. Methods: A single-center, prospective cohort study was conducted from 2019 to 2020. Consecutive patients underwent screening for proximal DVT by duplex ultrasound of both legs. Results: A total of 200 patients were enrolled, with 115 being male (57%). The mean (SD) age was 66.5 (16.4) years. The mean (SD) Acute Physiology and Chronic Health Evaluation II score was 27 (8). The cumulative incidence of DVT over 5 days was 7% (95% CI, 3.4%-10.6%). No clinically or radiologically diagnosed pulmonary embolism occurred in patients with DVT. No independent risk factor associated with DVT was identified. Hospital mortality in those with and those without DVT was 42.9% and 32.3%, respectively. There was no significant difference in the length of ICU or hospital stay or inpatient mortality between those with and those without DVT. Conclusion: Without thromboprophylaxis, the incidence of DVT in the Thai population remains low. A strategy of screening ultrasound 5 to 7 days after admission to the ICU may be a suitable alternative to anticoagulant prophylaxis in critically ill Thai patients without symptoms of venous thromboembolism.