Hyperbaric oxygen therapy prolongs survival of guinea pigs with Anaphylaxis.

Abstract

Anaphylaxis produces clinical illness and death when mast cells and basophils release pharmacologically active substances in response to immunoglobulin E. The clinical syndrome includes urticaria, bronchospasm, myocardial depression, increased capillary permeability, and systemic vasodilatation. Since hyperbaric oxygen causes peripheral vasoconstriction and tends to decrease edema formation, we tested its value in treating anaphylaxis in an animal model. Anaphylaxis was induced in young adult guinea pigs using chicken albumin. Anesthetized animals received hyperbaric oxygen (HBO) at 2.8 ATA or sham therapy (100% oxygen) in the same chamber. Blinded observers recorded the time to death. Animals in the control group died 5.5 (SD 0.7) min following injection of the antigen; those in the HBO group survived 22.8 (SD 13.2)min (P,0.01). HBO may prolong survival in the severe anaphylaxis as a result of increased oxygen delivery, inhibition of the endogenous release of mediators of anaphylaxis, or by decreasing capillary permeability and fluid loss as a result of induced vasoconstriction.