Hyperbaric oxygen (HBO) therapy may be a useful treatment to prevent the development of delayed neuropsychiatric sequelae (DNS) in patients with acute carbon monoxide (CO) poisoning. However, there is no clear consensus regarding the optimal number of HBO therapy sessions in patients with CO poisoning. Here, we compared the development of DNS after 3 and > 3 sessions of HBO therapy in patients with acute CO poisoning.

This prospective observational study recruited 299 patients with CO poisoning. Demographic and clinical information were obtained, including comorbidities, vital signs, and symptoms. Patients were divided into two groups according to whether they received 3 or > 3 sessions of HBO therapy (3 HBO vs. >3 HBO). A propensity score-matching process was used to balance potential prognostic factors in both groups.

Of the 299 patients with acute CO poisoning enrolled in this study, 183 (59.0%) were included in the analysis. Patients were excluded for the following reasons: age < 18 years, not underwent HBO therapy, discharged against medical advice, and loss to follow-up. The overall rate of DNS development was 17.5%. The >3 HBO group had a higher incidence of DNS development compared to the 3 HBO group (36.3% vs. 16.3%; p = 0.09). Propensity score-matching analysis revealed similar incidences of DNS (31.3% vs. 28.1%, respectively; p > 0.99).

There is a critical need to determine the optimal number of HBO therapy sessions for patients with acute CO poisoning. This study showed no difference in DNS development after 3 and > 3 sessions of HBO therapy.