Introduction: Hyperbaric oxygen treatment (HBOT) involves some risk of central nervous system (CNS) oxygen toxicity, which may be revealed by various signs and symptoms including seizures in patients breathing O2 at pressures of 2 ATA or higher. The aim of this study was to determine the incidence of such seizures in the Underwater and Hyperbaric Medicine Departments of two university hospitals.
Methods: We retrospectively evaluated 80,679 patient-treatments for 9 clinical indications to determine the incidence of seizures attributable to CNS O2 toxicity. Because different protocols were used for HBOT, the treatments were studied in four groups according to the chamber type used and the medical facility at which it was located.
Results: Only 2 seizures were documented, yielding an incidence of 2.4 per 100,000 patient-treatments. Both cases occurred in a multiplace chamber pressurized to 2.4 ATA with O2 delivered by mask for three x 30 min with 5-min air breaks.
Discussion: The seizure incidence reported here is lower than other studies published in the literature. The delivery of O2 by mask rather than hood may be a factor. Nevertheless, it appears that the risk of seizures due to CNS O2 toxicity during HBOT is very low as long as appropriate exclusion criteria and treatment profiles are used.