PORTABLE HYPERBARIC-OXYGEN THERAPY IN THE EMERGENCY DEPARTMENT WITH THE MODIFIED GAMOW BAG

Study objective: To compare oxygen administration by means of an infla table portable hyperbaric chamber with that through a nonrebreather ma sk for the elimination of carboxyhemoglobin (COHb). Design: Double-cro ssover prospective analysis. Setting: University emergency department, Level I trauma center. Participants: Twelve healthy paid adult volunt eers, all smokers. Interventions: Each subject smoked five cigarettes within 60 minutes. COHb levels were measured before and after smoking by means of cooximetry. Subjects then breathed hyperbaric and normobar ic oxygen in separate trials for 40 minutes. Normobaric oxygen was adm inistered through a nonrebreather face mask at 15 L/minute outside the Gamow bag. Hyperbaric oxygen was delivered inside the Gamow bag with a demand valve regulator mask at a pressure of 1.58 atmospheres absolu te pressure (8.5 psi). Venous blood (.5 mL) was sampled every 5 minute s. The specimens were iced and assayed for COHb in triplicate. Results : A significant increase in the elimination of COHb was observed for e ach subject in the Gamow bag (P<.05, repeated-measures ANOVA). The ave rage half-life for COHb elimination was 27.5+/-1.08 minutes (mean+/-SE ) (n=10). IV access failure occurred in two patients, with incomplete data as a result. Conclusion: The modified Gamow bag eliminated COHb m ore quickly than did nonrebreather mask oxygen and proved simple to op erate and maintain. No complications were noted for any of the subject s. One subject experienced claustrophobia, but it abated after the bag was inflated.