What Is Hyperbaric Oxygen Therapy?
Hyperbaric Oxygen Therapy is a new application of an established technology to help resolve certain recalcitrant, expensive or otherwise hopeless medical conditions. For certain indications, Hyperbaric Oxygen Therapy is the primary treatment modality; in
others it is an adjunct to surgical or pharmacologic interventions. Treatments are carried out in either a mono‑ or multiplace chamber. Monoplace chambers are for a single patient and is pressurized with near 100% oxygen so patients breathe ambient chamber oxygen directly. Multiplace chambers hold two or more people and are pressurized with compressed air; patients breathe oxygen via masks, head hoods or endotracheal tubes
How Does It Work?
At sea level, the atmosphere exerts 14.7 pounds per square inch of pressure which is also called one atmosphere absolute (1 ATA). Under sea level conditions, people breathe a mixture of air comprised of approximately 20% oxygen and 80% nitrogen. In Hyperbaric Oxygen Therapy, patients breathe near 100% oxygen and the atmospheric pressure inside the chambers is adjusted up from one-half to two or three times more than normal. Dr. Paul Harch, the leading Hyperbaric Oxygen Therapy researcher and clinician at LSU, recommends 1.5 atmospheres for most cases although each condition has its own protocol for optimal results (Tufts: 2016; Harch: 2016).
Hyperbaric Oxygen Therapy – breathing near 100% oxygen under more than one atmosphere – provides more oxygen at the cell level than is available by breathing 100% oxygen at sea level. The intake of near 100% oxygen under pressure saturates oxygen-carrying platelets as would be expected but it also pushes oxygen into the plasma which means up to 15% more oxygen than normal becomes available to cells. The net is that hyperbaric oxygen therapy provides more oxygen and nutrients to diseased or injury sites than would otherwise be available (Navy Diving Manual:2014). In addition, research shows that hyperbaric oxygen therapy stimulates the immune system and activates stem cells to generate new tissue in damaged areas (Thom SR et al:2006).
Therapeutic Principals of Hyperbaric Oxygen Therapy
Increased atmospheric pressure is of therapeutic value in treating decompression sickness and air embolism because it provides a physical means to reduce the volume of inert gas bubbles in the body; Provided increased atmospheric pressure is maintained for a sufficient time most of the bubble gas is dissolved back into the tissues, removed by perfusion and then eliminated in the lungs.
For many other conditions, the therapeutic principle of Hyperbaric Oxygen Therapy lies in its ability to drastically increase partial pressure of oxygen in the tissues of the body. The partial pressures of oxygen achievable using Hyperbaric Oxygen Therapy are much higher than those achievable by breathing pure oxygen at normobaric conditions (i.e. at normal atmospheric pressure);
In addition, Hyperbaric Oxygen Therapy increases the capacity to transport oxygen in the blood. Under normal atmospheric pressure, oxygen transport is limited by the capacity of oxygen to bind hemoglobin in red blood cells and very little oxygen is transported by blood plasma. Oxygen transport by plasma, however, is significantly increased using Hyperbaric Oxygen Therapy.
Recent evidence notes that exposure to hyperbaric oxygen mobilizes stem/progenitor cells from the bone marrow by a nitric oxide (NO)-dependent mechanism. This mechanism may account for the patient cases that suggest the recovery of damaged organs and tissues with Hyperbaric Oxygen Therapy (Wiki:2016).
How Does Hyperbaric Oxygen Therapy Treat Brain Injury?
Hyperbaric oxygen therapy improves the lives of Veterans and their families by treating injured brain tissue damaged by pressure waves, explosive devices, wounds and other blows to the head. Breathing 100% oxygen in a pressurized chamber raises oxygen levels throughout the body as well as the brain, reduces swelling, generates stem cell production at the point of injury, boosts the health of damaged cells and improves brain function.
The Benefits of Hyperbaric Oxygen Therapy
Under normal circumstances, around 20% of the air we breathe is oxygen. The oxygen taken into the body under normal atmospheric conditions is dissolved and transported by red blood cells. During hyperbaric oxygen therapy, 100% oxygen is taken in and dissolved and transported not only by red blood cells but another 15% or so of additional oxygen is dissolved in the body’s fluids, blood plasma, central nervous system fluids, lymph system, and bone.
Thus more oxygen than is usually available to the body is taken in and dissolved and carried under pressure throughout the body to injury areas where circulation is diminished or blocked. In this way, additional oxygen can reach damaged tissue and help the body support its own healing process by generating stem cells at the point of injury. This flow of increased oxygen under pressure greatly enhances the ability of white blood cells to kill bacteria, reduces swelling and allows new blood vessels to grow rapidly in the affected areas. It is a simple, non-invasive and painless treatment.
Contraindications of Hyperbaric Oxygen Therapy
Upper respiratory infections and chronic sinusitis make it difficult for the patient to clear his/her ears.
Often decongestants will open the sinuses; occasionally surgical myringotomy is needed to maintain open Eustachian tubes. Treatment can be halted for three or four days to allow respiratory infection to clear. High fever can predispose to oxygen seizures but in such cases drugs can lower the fever. In some patients with severe emphysema and COPD the only stimulus to breathe is hypoxemia because such patients have lost their sensitivity to normal levels of CO-2. These patients may cease breathing if placed in the hyperbaric chamber.
Patients with a lower than normal seizure threshold may be more prone to seizure due to oxygen toxicity. If hyperbaric oxygen therapy is required, however, additional anticonvulsants can be added to these patients’ regimens. Hyperbaric oxygen therapy is contraindicated for patients with pneumothorax or collapsed lung; caution is advised for patients with a history of spontaneous pneumothorax. Hyperbaric oxygen therapy is also not recommended for patients with active cancerous conditions.Hyperbaric oxygen therapy is not recommended for pregnant women except in life-threatening emergencies.
One person is treated at a time in Mono-place chambers and more than one patient is treated in multi-place chambers. Only 100% cotton gowns, which are supplied, is permitted in either chamber. No cosmetics, perfumes, deodorants, hair preparations, wigs, or jewelry may be worn. Patients should not take carbonated drinks or alcohol for at least four hours prior to treatment and not smoke or drink alcohol because those products interfere with the body’s ability to transport oxygen. Once inside the chamber, patients experience pressure changes similar to that felt in an airplane when climbing or descending. Prior to the treatment, patients are instructed in ways to equalize ear/sinus pressure by yawning, swallowing, or blowing through the nose while holding it shut.
During the treatment the patient will be breathing 100% oxygen, dispersing oxygen into the blood and blood plasma and delivering up to 15 times more oxygen to tissues than breathing room air. The treatment is usually 60 to 90 minutes depending on the diagnosis and the treatment protocol. Chambers with large acrylic windows allow technicians to closely monitor the patient and the patient to see out, Patients can usually watch TV, listen to music, or take a nap.
Side Effects of Hyperbaric Oxygen Therapy
Oxygen toxicity – particularly if therapy is given at too high a pressure (more than a 2.4 atmospheres). This risk is minimized by using lower pressures unless indicated by patient conditions. In addition, occasionally some patients may not tolerate high oxygen partial pressures – the cure for which is to discontinue oxygen. Serous otitis – Rarely, fluid accumulates in the ears as a result of changes in pressure can rupture ear and sinus membrane in which hyperbaric oxygen therapy should be discontinued and the patient referred to a physician.
Temporary worsening of nearsightedness (Myopia) and improvement of farsightedness (Presbyopia). After twenty or more treatments, notably in patients over 40, there may be a temporary diminution in the ability to focus on distant objects (Myopia). Vison typically returns to pre-treatment levels in about six weeks. Also, after twenty or more treatments, especially if the patient is over the age of 40, it is possible to experience an improvement in the ability to see things close up or to read things without glasses. However, this is temporary; vision returns to its previous level in about six weeks. Numb fingers. A few patients may notice numbing in the fourth and fifth fingers after twenty or more treatments. This is not of concern and should disappear within about six weeks.