Portable Hyperbaric Oxygen Therapy in the Emergency Department With the Modified Gamow Bag

Abstract

Study objective: To compare oxygen administration by means of an inflatable portable hyperbaric chamber with that through a nonrebreather mask for the elimination of carboxyhemoglobin (COHb). Design: Double-crossover prospective analysis. Setting: University emergency department, Level I trauma center. Participants: Twelve healthy paid adult volunteers, 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 normobaric oxygen in separate trials for 40 minutes. Normobaric oxygen was administered 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 absolute pressure (8.5 psi). Venous blood (.5 mL) was sampled every 5 minutes. The specimens were iced and assayed for COHb in triplicate. Results: A significant increase in the elimination of COHb was observed for each subject in the Gamow bag ( P<.05, repeated- measures ANOVA). The average 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 more quickly than did nonrebreather mask oxygen and proved simple to operate and maintain. No complications were noted for any of the subjects. One subject experienced claustrophobia, but it abated after the bag was inflated. [Jay GD, Tetz DJ, Hartigan CF, Lane LL, Aghababian RV: Portable hyperbaric oxygen therapy in the emergency department with the Gamow bag. Ann Emerg Med December 1995;26:707-711.]