CENTRAL-NERVOUS-SYSTEM OXYGEN-TOXICITY DURING HYPERBARIC TREATMENT OFPATIENTS WITH CARBON-MONOXIDE POISONING

Hyperbaric oxygen (HBO2) is associated with a recognized risk for clin ical central nervous system (CNS) toxicity. The risk for oxygen convul sions during routine hyperbaric treatment of most routine conditions i s extremely tow. Previous observations have suggested that the inciden ce of CNS toxicity during HBO2 treatment for carbon monoxide (GO) pois oning may be increased, both because of CNS injury caused by the poiso ning and because higher treatment pressures are often utilized for thi s condition. This study reviews data from 900 GO-poisoned patients tre ated with HBO2 at Virginia Mason and Duke University Medical Centers f rom 1987 to 1996. One-third of the patient population was treated at e ach of the three HBO2 treatment pressures most commonly utilized for C O intoxication in North American multiplace chambers. Patient characte ristics were similar in all groups. Among the 300 consecutive patients treated at each pressure, there was one seizure at 2.45 atm abs (0.3% ), nine seizures at 2.80 atm abs (2.0%), and six seizures at 3.00 atm abs. This difference is statistically significant (P = 0.032; Fisher's Exact Test). The potential difference in seizure risk should be consi dered when selecting the HBO2 treatment pressure for CO poisoning.