Hyperbaric oxygen therapy (HBOT) is the process by which a patient is given 100% pure oxygen in a chamber that has been set at a very high pressure (about two or three times the pressure you find at sea level). As a result, the oxygen breathed in is at about 15 times the concentration of oxygen you'd find in normal air.
The therapy started off as a treatment for deep sea divers suffering from the bends (or decompression sickness), a condition where the diver surfaces too quickly causing a sudden decrease in pressure so that nitrogen is released from the body's tissues and forms bubbles in the circulation. By putting the diver in a high pressure hyperbaric oxygen chamber the nitrogen bubbles are compressed and oxygen levels in the tissues are returned to normal.
Hyperbaric oxygen can also be used to treat cases of carbon monoxide poisoning. Carbon monoxide gas is released by the burning of gasoline, oil and other fuels. Once inhaled the carbon monoxide sticks to the hemoglobin molecules in the blood which are normally in charge of ferrying oxygen to the body's tissues. This prevents the binding of oxygen to the hemoglobin. Hyperbaric oxygen pushes off the carbon monoxide to allow the hemoglobin to function properly once more.
HBOT can also stimulate the growth of blood vessels, cause wounds to heal more quickly and help with certain types of infections. Increasing the pressure at which the pure oxygen is administered allows for an increase in dissolved oxygen in the blood. This means more oxygen can be delivered to the body's tissues. In the case of infection, hyperbaric oxygen can help the immune cells fight bacteria especially when there is a lack of oxygen getting to the site of infection. High pressure oxygen also causes blood vessels to constrict so less blood is pumped to the injured area to reduce swelling and pressure build-up. This last benefit may further help heal athletes' sports injuries more quickly.
Aside from the accepted uses for HBOT in the medical profession, there are a number of 'alternative' uses for the therapy. These include using HBOT for multiple sclerosis, AIDS, cerebral palsy and stroke patients. There is still no clear-cut evidence that using HBOT on such patients can show any improvement.
In the case of stroke patients, the stroke has occurred because a blood vessel bringing oxygen to the brain has become blocked or burst. A number of nerve cells in the oxygen- deprived brain die and this can lead to memory loss, speech impairment, paralysis and various other problems. The reasoning behind using HBOT on stroke patients is that pure oxygen at high pressures might regenerate some of the tissues in the brain that have been damaged by lack of oxygen caused by the stroke. Only the outer brain tissue can be repaired, though many stroke victims suffer damage that goes deep into the brain. But the FDA in the US and the Health Protection Branch in Canada have not approved the use of HBOT for stroke victims. The reason? There are very few studies that show stroke patients improving when using HBOT. Large randomized clinical trials are still needed to see if HBOT can benefit these stroke patients or not.
