ABSTRACT
Hyperbaric oxygen (HBO2) therapy is a treatment modality in which a person breathes 100% O2 while exposed to increased atmospheric pressure. Treatments are performed in either a monoplace or a multiplace chamber. Therapeutic mechanisms of action for HBO2 are based on elevation of both hydrostatic pressure and the partial pressure of O2. Elevation of the hydrostatic pressure raises gas partial pressures in the body and causes a reduction in the volume of gas-filled spaces according to Boyle’s law. This action has direct relevance to pathologic conditions in which gas bubbles are present in the body, such as arterial gas embolism and decompression sickness. Reactive oxygen species (ROS) are generated as natural by-products of metabolism and they include superoxide, hydrogen peroxide, hypochlorous acid and hydroxyl. ROS are increased in many organs by hyperoxia. Scavenging antioxidants combat the overproduction of reactive species.
