Glasgow coma scale may be a predictive factor for delayed neurological sequelae after carbon monoxide poisoning: a retrospective analysis of a nationwide multicenter observational registry in Japan

Acute carbon monoxide poisoning (ACOP) is a cause of accidental or deliberate deaths worldwide. Subsequent complications, particularly delayed neurological sequelae (DNS), are preventable and treatable based on their pathophysiology. Hyperbaric oxygenation therapy (HBO) is a potential procedure for preventing and treating DNS; however, the effects of HBO on DNS are unclear and debated. In the present study, we investigated which factors are associated with the development of DNS and the effects of HBO in patients with ACOP. We performed retrospective subanalyses of the COP-J registry, focusing on adults who underwent HBO, regardless of whether they developed DNS. The multivariable analysis showed that the Glasgow coma scale (GCS) on admission was significantly associated with DNS (odds ratio 0.736; 95% confidence interval 0.608-0.892; P = 0.002). The receiver operating characteristic curve analysis of GCS for DNS revealed a cutoff value of 12.5 according to Youden's index (sensitivity 80.8%, specificity 76.9%). This retrospective analysis of a nationwide Japanese registry of ACOP showed that low GCS scores on admission could be a predictive factor for DNS, with a possible cutoff value of ≤12, in patients who undergo HBO.