hyperbaric oxygenation [Gk, hyper + baros, weight, oxys, sharp, genein, to produce] , the administration of oxygen at greater-than-normal atmospheric pressure. The procedure is performed in specially designed chambers that permit the delivery of 100% oxygen at atmospheric pressure that is three times normal. The technique is used to overcome the natural limit of oxygen solubility in blood, which is about 0.3 mL of oxygen per 100 mL of blood. In hyperbaric oxygenation, dissolved oxygen can be increased to almost 6 mL per 100 mL and the PO2 in blood may be nearly 2000 mm Hg at 3 atmospheres absolute. Hyperbaric oxygenation has been used to treat carbon monoxide poisoning, air embolism, smoke inhalation, acute cyanide poisoning, decompression sickness, wounds, clostridial myonecrosis, and certain cases of blood loss or anemia in which increased oxygen transport may compensate in part for hemoglobin deficiency. Factors limiting the usefulness of hyperbaric oxygenation include the hazards of fire and explosive decompression, pulmonary damage and neurological toxicity at high atmospheric pressures, cardiovascular debility of the patient, and the need to interrupt treatments repeatedly because exposures at maximum atmospheric pressures must be limited to 90 minutes. Also called hyperbaric oxygen therapy.
