hyperbaric oxygenation

Hyperbaric oxygenation

Administration of oxygen in a compression chamber at an ambient pressure greater than 1 atmosphere, in order to increase the amount of oxygen in organs and tissues.

Mentioned in: Retinal Artery Occlusion

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hyperbaric oxygenation

Etymology: 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 neurologic 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.

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hyperbaric [hi″per-bar´ik]

characterized by greater than normal pressure or weight; applied to gases under greater than atmospheric pressure, or to a solution of greater specific gravity than another taken as a standard of reference.

hyperbaric oxygenation (HBO) exposure to oxygen under pressure greater than normal atmospheric pressure. This treatment is given to patients who, for various reasons, need more oxygen than they can take in by breathing in the normal atmosphere or using an oxygen mask. Called also high pressure oxygenation.

The patient is placed in a sealed enclosure called a hyperbaric chamber. Compressed air is introduced to raise the atmospheric pressure to several times normal. At the same time the patient is given pure oxygen through a face mask. The increase in atmospheric pressure forces enough air into the patient so that the pressure within the body equals that in the hyperbaric chamber. Thus all the tissues become flooded with more than the usual supply of oxygen. While the patient is in the chamber, pressure changes are controlled with extreme care to avoid injury to the lungs or other tissues.

Use of Hyperbaric Oxygenation. This treatment may be administered in many types of disorders in which oxygen supply is deficient. If, because of injury or disease, the heart or lungs are unable to maintain good circulation and oxygenation, the increase in oxygen can temporarily compensate for this reduction. If injury or disease has caused the breaking or blocking of arteries, an extra supply of oxygen in the vessels that are still functioning will help.

Decompression sickness related to diving is one of the most common uses for hyberbaric oxygen therapy. The effectiveness of this therapy has also been demonstrated for treatment of arterial gas emboli, treatment and prevention of bone damage caused by radiation therapy, and treatment of clostridial myonecrosis. It is also sometimes used to promote healing in skin grafts.

Carbon monoxide poisoning can also be treated by hyperbaric oxygenation. Carbon monoxide, displacing the oxygen from hemoglobin, usually causes asphyxiation, but hyperbaric oxygenation can often keep patients alive until the carbon monoxide has been eliminated from the body.

Claims have been advanced about the effectiveness of hyperbaric oxygenation for a wide variety of disorders and diseases, including cancer, neurological disorders, and arthritis. To date, there have been no randomized clinical trials supporting such uses.

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oxygenation [ok″sĭ-jĕ-na´shun]

saturation with oxygen.

extracorporeal membrane oxygenation (ECMO) a technique of providing respiratory support; the blood is circulated through an artificial lung consisting of two compartments separated by a gas-permeable membrane, with the blood on one side and the ventilating gas on the other. It was originally used exclusively in newborns but is now being used more and more in adults.

high pressure oxygenation (hyperbaric oxygenation (HBO)) see hyperbaric oxygenation.

pulsed oxygenation a technique by which oxygen is delivered to the patient only during inhalation rather than continuously during the respiratory cycle; used to conserve oxygen in patients using chronic low-flow oxygen therapy at home.

transtracheal oxygenation a technique of oxygen administration for patients requiring chronic oxygen therapy, in which oxygen is administered at low flow through a catheter passing directly into the trachea. This may be more cosmetic for patients and may require a lower flow of oxygen than other methods such as the use of a nasal cannula.

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hyperbaric

characterized by greater than normal pressure or weight; applied to gases under greater than atmospheric pressure, or to a solution of greater specific gravity than another taken as a standard of reference.

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hyperbaric oxygenation

exposure to oxygen under conditions of greatly increased pressure; abbreviated HPO, for high-pressure oxygenation. This treatment is given to patients who, for various reasons, need more oxygen than they can take in by breathing while in the ordinary atmosphere, or even in an oxygen tent.

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oxygenation

saturation with oxygen.

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hyperbaric oxygenation

exposure to oxygen under conditions of greatly increased pressure See also hyperbaric oxygenation.