Hyperbaric Oxygen Therapy (HBO) is breathing 100% oxygen while the whole body is pressurized to greater than sea level for a limited period of time. This usually takes place in a one (1) person chamber (monoplace) or a multiple person chamber (multiplace). HBO is the primary treatment for Carbon Monoxide Poisoning, Decompression Sickness, and Air Embolisms. It is also accepted as an adjunct treatment for many other conditions. The physiological effects that describe what occurs during HBO can be broken down into five general categories: 1. Mechanical Effect of Increased Pressure: Any free gas that is trapped in the body will decrease in size as the pressure increases. 2. Mass Action of Gases or Gas wash out: If a body is flooded with a single gas, all others will tend to be washed out. This can cause an equilibrium shift in some chemical reactions that are important. 3. Vasoconstriction: The administration of oxygen at high pressure causes the blood vessels to constrict. This helps fight swelling and certain types of fluid loss. Even with this vasoconstriction, enough oxygen is carried by the blood for the tissue oxygen content to show a net increase. 4. Anti-bacterial Effects: Many of the defense mechanisms in the human body are dependent on oxygen. A low level of oxygen in the tissues reduces the effectiveness of the ingestion and killing of bacteria by the white blood cells. When a body is subjected to Hyperbaric Oxygen Therapy, reoxygenation of the tissue allows phagocytosis and the other defense mechanisms of the body to operate more effectively. 5. Anti-ischemic Effect: Hyperbaric Oxygen Therapy dissolves extra oxygen into the blood plasma. The increased level of oxygen promotes several beneficial effects: - The breakdown of old dead bone - The formation of new capillaries in wound areas - The breadown of many complex toxins - This anti-ischemic effect also helps ischemic tissue meet the increased metabolic needs that are necessary during healing.