Risk factors for delayed encephalopathy following carbon monoxide poisoning: Importance of the period of inability to walk in the acute stage

OBJECTIVE: Delayed neurological sequelae (DNS) is a serious complication that occurs after acute carbon monoxide (CO) intoxication. The study identified factors for predicting DNS development for the purpose of improving CO intoxication treatment strategies. METHODS: The medical records of 65 patients admitted to Shizuoka Saiseikai General Hospital between 2004 and 2020 due to CO poisoning were retrospectively reviewed. Univariate and multivariate logistic regression analyses were performed, using a range of evaluated items as explanatory variables and the development of DNS as the response variable. RESULTS: Patients who developed DNS were found to have higher peak creatine kinase (CK) (odds ratio, 1.0003; 95% CI, 1.0001–1.0005; P<0.001), and experienced a greater number of days during which walking was impossible in the acute stage following intoxication (odds ratio, 1.011; 95% CI, 1.005–1.018; P<0.001) according to the univariate analysis. Multivariate analyses indicated that DNS development was related to the score, peak CK (U/L) + 40 × the number of days in which walking was impossible. The model demonstrated an area under the receiver operating characteristic curve (AUC) of 0.96 (95% CI, 0.91–1.00), and DNS was predicted with 100% sensitivity and 82% specificity. CONCLUSION: An indicator that incorporates the number of days that walking is impossible for a patient could be useful in planning therapeutic strategies.