Use of hyperbaric oxygen in toxicology.

HBO has become recognized as a potential treatment for a variety of toxins. HBO is helpful because it provides an excess of dissolved oxygen, which not only can sustain life in the absence of hemoglobin, but in some cases can actually increase the clearance of toxins. In addition, it is now apparent that HBO serves more complex roles in toxicological injuries, such as modifying PMN-endothelial interactions and preventing oxidative tissue injury. The major drawback of HBO therapy is the lack of controlled clinical trials, partly due to the rarity of most of the toxins discussed. In fact, the field of hyperbaric medicine has come under increasing criticism for this failure. There is a physiologic basis for use of HBO in the toxins discussed. Unfortunately, only for CO is patient volume adequate for studies to document efficacy. Regarding the other toxins mentioned, the use of HBO should be reserved for carefully selected cases in which patients have failed routine care or are at risk for delayed effects.