Indications & Rationale for Hyperbaric Oxygen
By Alexis Rohlin.
Hyperbaric oxygen pressurization is a medical treatment where the patient is placed into an air-tight chamber. The chamber is pressurized at higher than normal atmospheric pressures and the air supply is one hundred per cent oxygen. This procedure increases the overall circulation of the blood, which stimulates the growth of new blood vessels in locations with reduced circulation, and aids in treating infections by helping white bloods cells to fight off infections.
- The Undersea and Hyperbaric Medical Society was formed in 1967. The UHMS created the official definition of Hyperbaric Oxygen Therapy and put together an indications list for Hyperbaric Oxygen Treatment. This list includes air/gas embolisms, carbon monoxide or cyanide poisoning, clostridial myositis or gas gangrene, acute traumatic ischemias such as crush injuries and compartment syndrome, decompression sickness, enhancement of healing in problem wounds, anemia or exceptional blood loss, intracranial abscesses, necrotizing soft tissue infections, refractory osteomyelitis, delayed radiation injuries in soft tissues or bony necrosis, compromised skin grafts and flaps, and thermal burns.
- The principle rationale behind the use of Hyperbaric Oxygen Therapy is that it’s use decreases oxygen tension in tissues. Many micro-organisms that cause infections and systemic illnesses are intolerant to oxygen, and by raising the oxygen levels of an infected person’s blood, the micro-organisms die off and the infection is eliminated. Anaerobic infections, or infections caused by viruses, bacteria, and fungi that don’t need oxygen to live, develop because the body cannot fight them off, or send enough oxygen to its white blood cells to allow them to kill off the microbe invasion.
- Gas gangrene is caused by Clostridium perfringens, a toxin creating bacteria that is sensitive to oxygen. The toxins they create are known as exotoxins, and they can liquefy tissues and inhibit the body’s defence mechanisms so that it can’t fight off infection. Gangrene can advance rapidly and can destroy healthy tissue over the course of hours. Being placed into a hyperbaric chamber increases the amount of oxygen dissolved in the blood and halts the exotoxin production, which then stops the bacteria from killing off any more body tissue. Doing this prevents patient’s infected limbs from having to be amputated in a desperate attempt to stop the gangrene from spreading to the rest of the body.
Air Gas Embolism
- Decompression sickness is caused by a rapid decrease of pressure on a human body, such as when a deep sea diver rapidly comes up to the ocean’s surface after diving down to the ocean’s floor. The increased pressure caused by the ocean’s depths causes the inert gases that naturally occur in the human body to build-up in body tissue. Upon decompression, the built-up gases are eliminated. When decompression happens too fast, the inert gases that have built-up in the tissues and blood of the body cannot be safely removed, and they form gas bubbles called emboli in the blood stream.
- Emboli block blood flow in the arteries and veins. They can cause the blood platelets to clump up and obstruct blood vessel walls, which causes it to leak fluids into surrounding tissues. This causes swelling, which in turn reduces blood flow in the tissues as well. These bubbles can cause pain in the joints known as “the Bends”, dizziness, extreme fatigue, hearing loss, numbness, tingling, skin rashes, paralysis, and weakness in the arms and legs. When this happens and blood circulation has been compromised in the body, oxygen cannot be delivered to the affected areas of the body and tissues and organs may soon begin to die. This may result in irreversible physical disabilities and may even be fatal. It can damage the brain, heart, lungs, impair vision, and paralyze limbs.
- The increased pressure of a Hyperbaric Chamber reduces the size of the gas bubbles and forces the gas to dissolve back into the bloodstream. Higher levels of oxygen in the blood acts as a diffusion gradient that allows the gas to leave the bubbles. Once this occurs, blood flow is restored. Swelling of the surrounding tissues stops as they once again begin receiving oxygen.