Effect of hyperbaric oxygen therapy on early features of carbon monoxide poisoning focusing on neurological symptoms.

backgroundCarbon monoxide (CO) intoxication due to suicide attempts or accidental exposure is a critical problem in Korea. Patients with CO intoxication can experience various neurologic and systemic symptoms. Although some of these symptoms may result in severe sequelae, the pathophysiological mechanisms remain unclear. Hyperbaric oxygen (HBO) therapy is the most important treatment for CO poisoning. However, standardized protocols remain unclear, and most related studies focus on the association of HBO therapy with the development of sequelae. Therefore, we intended to conduct studies focusing on the early features of CO intoxication.

methodsA retrospective descriptive cross-sectional study was conducted based on an analysis of medical records for patients with CO intoxication treated with hyperbaric oxygenation from January 2020 to March 2023. We excluded patients with a misdiagnosis, duplicate registration, or refusal of treatment. Patients were divided into two groups on the basis of their mental status at the time of presentation, and their demographic, physiological, and environmental characteristics were compared. Chi-square tests and t tests were performed, and 95% confidence intervals were calculated.

resultsOut of 525 patients identified with CO exposure, 288 patients were included in this study. A total of 186 (64.6%) patients were male, and most were in their mid-forties. Alert patients appeared to visit the hospital earlier compared with other patients (431.82 ± 975.20 vs. 151.78 ± 229.96, p value < 0.001). The proportion of suicide attempts was greater in the nonalert group (94 (56%) vs. 101 (84.2%), p value < 0.001). The frequencies of myocardial damage, shock, and ventilator treatment were 51 (42.5%), 6 (5%), and 13 (10.8%), respectively, and were greater in the unconscious group. Most symptoms usually improved almost completely at the early stage of the HBO therapy protocol.

conclusionsIn general, patients who are not alert at the time of presentation receive more intensive HBO therapy. According to our study, most intoxication symptoms improve during the early phase of HBO therapy, and delayed neuropsychiatric sequalae can occur in the future, even in initially alert patients. Therefore, physicians should be more careful with patients with neurological symptoms, evidence of myocardial damage, or severely elevated creatine phosphokinase levels, and these patients should be fully administered HBO therapy.