Incidence, timing, location, risk factors, and nomogram of lower extremity deep venous thrombosis after acute carbon monoxide poisoning

Data on lower extremity deep venous thrombosis (DVT) following acute carbon monoxide (CO) poisoning are lacking. This study aimed to identify the incidence rate, timing, locations, risk factors, and nomogram of lower extremity DVT after acute CO poisoning.A total of 203 patients with acute CO poisoning from October 2019 to April 2021 were included in this retrospective study. Multivariate logistic regression analysis was performed to identify the independent risk factors associated with lower extremity DVT. Nomogram was drawn and area under the curve (AUC) was calculated to predict lower extremity DVT.Overall, 14.3% (29/203) had lower extremity DVT, with incidence rates of 2.5% (5/203) for proximal DVT and 11.8% (24/203) for distal DVT. The lower extremity DVTs involved intermuscular vein in 28 patients, popliteal vein in 5 patients, and posterior tibial vein in 3 patients. The mean time from end of exposure to diagnosis of lower extremity DVT was 1.24 days. Among 29 lower extremity DVT cases, 6 (23.1%) DVT cases had thrombolysis. Multivariate logistic regression analysis revealed that long coma duration (P < 0.001) and high D-dimer levels (P < 0.001) were significantly associated with lower extremity DVT. The discrimination of nomogram was good with AUC of 0.93 (95% CI, 0.89-0.98).Clinicians should be aware of and concerned with lower extremity DVT after acute CO poisoning, especially in patients with long coma duration and high D-dimer levels.