Improvement of occipital alpha activity by repetitive hyperbaric oxygen therapy in patients with carbon monoxide poisoning: A possible indicator for treatment efficacy

Objectives: The main aim of this study was to evaluate the efficacy of repetitive hyperbaric oxygen (HBO) treatments with monitoring of quantitative electroencephalography (qEEG) for symptoms of acute carbon monoxide (CO) poisoning and prevention of delayed neuropsychiatric sequelae. Methods: Eight patients with acute CO poisoning received repetitive HBO treatments five times a week and qEEG was recorded once a week. Peak alpha frequency, peak alpha power, and absolute and relative alpha power in the occipital region were evaluated. The repetitive HBO treatments were discontinued when the peak alpha frequency increased to and maintained a maximum in each patient. Results: The mean number of HBO treatments was 20.3. The peak alpha frequency and the relative alpha power significantly increased after repetitive HBO treatments. The absolute alpha power and the peak alpha power insignificantly improved. Total numbers of HBO treatments were not correlated with age, duration of CO exposure, initial level of COHb, or interval to the first HBO treatment. After the completion of repetitive HBO treatments, no patient developed delayed neuropsychiatric sequelae. Conclusions: These results suggest that repetitive HBO treatments may prevent the delayed neuropsychiatric sequelae of CO poisoning when applied individually with monitoring of the peak alpha frequency as an indicator of efficacy. (C) 2005 Elsevier B.V. All rights reserved.