Hyperbaric Oxygen Therapy
The concept of putting patients in a recompression chamber and raising the ambient pressure around them for therapeutic purposes was at first without scientific basis. Perhaps intuitively it "seemed like a good idea" to a British clergyman, Henshaw. In 1662, he built a sealed chamber he called a "Domicilium." Chamber pressure was controlled by valved organ bellows, which could either raise or lower pressure depending on adjustment of the valves. He felt that acute disease of all kinds would respond to increased ambient pressure whereas chronic diseases were better treated with more rarefied air.
A French surgeon named Fontaine, in 1879, built a mobile operating room on wheels, which could be pressurized. Over 20 surgical procedures were performed in this unit using nitrous oxide as the anesthetic. Deep surgical anesthesia was possible because its increased effective percentage accompanied by a higher oxygen partial pressure rendered it safer. Compressed air at two atmospheres gives an effective level of 42% inhaled oxygen. Hernias were seen to reduce more easily and the patients were not their normal cyanotic color when coming out of anesthesia.
Fontaine's experiments with hyperbaric surgery were the only semi-scientific efforts made during the entire compressed air era, which ended in 1930. In 1891, J.L. Corning, the first physician to administer a spinal anesthetic, introduced compressed air therapy to the United States and was the first to operate his compressor with electric power.
Orville J. Cunningham, a professor of anesthesia at the University of Kansas in Kansas City, was the last of the great compressed air enthusiasts. He started out legitimately enough, noting that people with heart disease and certain other circulatory disorders did poorly when living at altitude, but improved on return to sea level. Taking this concept one step further, he felt that increased atmospheric pressure would be still more beneficial. During the flu epidemic of 1918, he placed a moribund young resident physician in a chamber which had been used for animal studies and by compressing him to two atmospheres was able to successfully oxygenate him during his hypoxic crisis. Having thus proved to himself that his concept was sound, he constructed an 88-foot long chamber, 10 feet in diameter, in Kansas City and began to treat a multitude of diseases, most of them without scientific rationale.
Mr. Timkin of the Roller bearing Company came under his care and apparently had a spontaneous recovery from a uremia while in Cunningham's chamber. In gratitude to Dr. Cunningham, Timkin built him the largest hyperbaric chamber ever constructed. It was steel sphere six stories high and 64 feet in diameter. This "steel ball hospital," located in Cleveland, Ohio, accommodated a smoking room on the top floor, plush carpeting, dining rooms and individual rooms. It could reach three atmospheres pressure.
Cunningham felt that some anaerobic-organism "which could not be cultured" was responsible for a host of diseases including hypertension, uremia, diabetes and cancer and that compressed air therapy helped inhibit this organism. The AMA and the Cleveland Medical Society, failing to receive any scientific evidence for his rationale, finally forced him to close in 1930. Unfortunately, the steel ball hospital was broken up for scrap during World War II. It would have made a magnificent museum.
The Advent of Hyperbaric Oxygen
Modern scientific use of the hyperbaric chamber in clinical medicine began in 1955 with the work of Churchill-Davidson. He was the first to attempt using high oxygen environments to potentate the effects of radiation therapy in cancer patients. That same year, Ite Boerema, Professor of Surgery of the University of Amsterdam in Holland, proposed using hyperbaric oxygen in cardiac surgery to prolong the patient's tolerance to circulatory arrest.
Effects of Oxygen Solubility In Plasma
Placing the patient in the hyperbaric chamber raises oxygen tensions 10 to 13 times above their normal level when the patient is breathing 2.8 ATA oxygen, six volumes percent of oxygen area in the dissolved plasma - the mean extraction rate of oxygen in the body. This is a simple physical event. The plasma is thus capable of carrying enough oxygen to meet the needs of the body's tissues. The overall effect is that the hemoglobin is still fully saturated on the venous side. Depending however, on the physiologic or pathophysiologic status of the patient, the effects of high oxygen pressure on the functions of various organs, structures and biochemical reactions, can be myriad. These include suppression of alpha-toxin production in gas gangrene, enhancement of leukocyte-killing activity, decrease in white cell adherence to capillary walls, vasoconstriction in normal vessels, restoration of fibroblast growth and collagen production, stimulation of superoxide dismutase production, preservation of adenosine triphosphate in cell membrane with secondary reduction in tissue edema, suppression of selected immune responses (experimental allergic encephalomyelitis in the guinea pig), enhancement of osteoclast activity, increased capillary proliferation, decreased flexibility of the ocular lens ( visual changes), suppression of surfactant production in the lung, termination of lipid peroxidation in CO poisoning, hastening removal of CO from hemoglobin, etc.
What is Hyperbaric Oxygen Therapy?
Hyperbaric Oxygen Therapy is a medical treatment that is used to treat a limited but diverse series of illnesses. It may be the primary treatment for some disorders, but it is often used as part of a combined program involving antibiotics and surgery. In order to provide patients with hyperbaric oxygen therapy, a pressurized chamber is necessary. The patient is placed within the chamber, which is then compressed to the level ordered by the consulting hyperbaric physician, using pure oxygen.
Hyperbaric oxygen is a simple concept. The air we breathe contains 21% oxygen. Providing 100% oxygen by facemask without the use of a chamber has certain limited benefits. By providing pure oxygen in a pressurized chamber we are able to deliver 2-3 times that which can be provided by breathing 100% oxygen with no increase in pressure. The “hyperbaric” (or high pressure) dose of oxygen offers distinct therapeutic benefits.
How Does Hyperbaric Oxygen Therapy Work?
Hyperbaric oxygen provides more oxygen dissolved in plasma than is possible by just breathing oxygen at sea level. Hyperbaric oxygen therapy is given in a pressurized chamber that encloses the entire body. The patient breathes oxygen at pressures greater than one atmosphere absolute (ATA), which is the equivalent of sea level. All of the benefits provided by hyperbaric oxygen therapy are the result of this extra oxygen being carried within the bloodstream.
Reprinted with Permission
