HBOT – Hyperbaric Oxygen Therapy means overpressure or high-pressure. So in Hyperbaric oxygen therapy (HBOT), you will be breathing in 100% oxygen while under increased atmospheric pressure. You will be resting in a pressurized chamber to a higher level than atmospheric pressure. In an HBOT chamber, the air pressure is increased from two to three times higher than normal air pressure. This pressurized condition allows the lungs to receive more oxygen than under normal air pressure. This therapy is used clinically in different ways to treat several medical conditions.
History of HBOT
HBOT as a treatment arose in the 1600s. A British clergyman named Henshaw built the first hyperbaric chamber and used it to treat many diseases. A French surgeon Fontaine continued with his version of treating patients under increased pressure in 1879. In 1928, Dr. Orville Cunningham, a professor of anaesthesia, erected a pressurized structure that was known as the “Steel Ball Hospital.” The clinical setting could reach up to 3 atmospheres of pressure. This pressurized oxygen cured a patient of flu.
HBOT has gained acceptance in recent years as an adjunctive treatment in human medicine. Today, there is a surge in the research on the physiology of pressure and access to hyperbaric equipment. The clinical application of hyperbaric therapy has grown with these demands.
Blood carries oxygen throughout our body. An adequate supply of oxygen is essential for body tissues to function. Damaged or harmed tissues demand an increased oxygen level to promote healing and to fight infections.
The cardio-respiratory system plays a vital role in maintaining adequate oxygen levels in the body. It allows the cells to meet their ongoing demand both in health and disease. Under normal conditions, oxygen delivery is a demand-driven process. Meaning, the amount of oxygen delivered is controlled by the amount of oxygen required by the cells.
Sometimes, due to pathological conditions, the cardio-respiratory system may be unable to provide enough oxygen to the tissues. This is why intensive care patients must receive bulk oxygen transport frequently. However, this is only the first part of the process involved in the ultimate delivery of oxygen. The rest of it makes sure the oxygen reaches the tissues.
Microcirculation is the circulation of blood in the smallest of blood vessels. It can be affected by damaged tissue capillaries due to therapeutic radiation, diabetes, burns, infection, and other injuries. Impaired microcirculation can prevent red blood cells from reaching tissues and delivering oxygen, resulting in tissue hypoxia, tissue breakdown, and impaired healing. In HBOT, the high dissolved oxygen levels can overcome even the impaired microcirculation.
Oxygen in the plasma can travel much farther into the tissues than the oxygen carried by hemoglobin in the red blood cells. This stimulates the release of substances called growth factors and stem cells to fight against infection and tissue trauma. HBOT helps maintain the storage of gases in the blood under normal conditions. It stimulates tissue function and promotes healing.
It involves the following steps:
- Oxygen from the atmosphere reaches the alveolus, which is the gas-fluid interface in the lungs. Here it diffuses to the capillary blood where it gets transported to all parts of the body. Now, the heart’s pumping distributes oxygen to the body till the smallest blood vessels.
- Finally, oxygen is released from haemoglobin and diffuses into the cells where it helps maintain cell functions.
Thus, HBOT is hypothesized as an alternative means to increase oxygenation of tissues than standard respiratory and ventilator treatments.
Hyperbaric chambers are of two major categories based on their construction:
- A mono-place hyperbaric chamber can accommodate a single person at a time and is pressurized with 100% oxygen
- A multi-place hyperbaric chamber can hold more than one person at a time. Here, the patient inside the pressurized chamber will inhale oxygen through either a head tent or a mask.
Hyperbaric oxygen normalizes and regulates all biological functions as it prevents or corrects hypoxia, which is the underlying factor for almost all ailments. HBOT also stimulates the immune system and strengthens skin.
A person undergoing HBOT can heal wounds anywhere in the body, decrease wound healing time through increased efficiency, enhance the brain’s ability to regain neurologic function, reducing swelling/pain and lead an improved quality of life
Some of the commonly applied medical benefits of HBOT are:
The blood vessels in our body often get damaged by wound injuries. They release fluids that accumulate into the tissues and cause swelling. This swelling deprives the damaged cells of oxygen and leads to cell death.
HBOT brings oxygen-rich plasma to oxygen-deprived tissues. Flooding of these tissues with oxygen reduces their swelling. HBOT aims to break the cycle of swelling, oxygen starvation, and tissue death.
When blood supply returns to the tissues after they have been oxygen-deprived, there is severe tissue damage, also called reperfusion injury. The sudden interruption of blood flow to these tissues leads to a series of events inside the damaged cells resulting in the release of harmful free oxygen radicals. These radicals can cause irreversible tissue damage, leading to blocked blood vessels and cessation of blood flow and healing.
When exposed to pressurized oxygen, the body’s scavengers feed on free oxygen radicals and thus allow the healing of cells.
Increased oxygen concentration in tissues can restrict certain pathogens and resist infection. Also, HBOT improves the ability of white blood cells to search and destroy invaders.
Pressurized oxygen encourages the growth of blood vessels as it stimulates cells to produce certain substances like vascular endothelial growth factors. Endothelial cells thus activated, are necessary for collagen production.
Increased levels of oxygen and decreasing levels of carbon dioxide in the blood can significantly enhance respiratory symptoms.
HBOT dissolves oxygen into the blood, body fluids, cerebrospinal fluid, bone tissue, and lymph nodes. Oxygen-rich fluids in the body can then travel to areas where blood circulation is blocked.
In people with traumatic brain injury and suffering acute neurocognitive impairments, the usage of HBOT has been safe and effective in improving brain function. HBOT has reduced the risk of death and boosted the final GCS and reduced the duration of hospital stay.
A hyperbaric chamber is also known as a decompression or recompression chamber. For instance, when a diver ascends too quickly, they suffer damages from an increased difference in pressure formed in a short time. It can lead to decompression sickness.
HBOT eliminates nitrogen bubbles from the blood and encourages the cells of the body to repair themselves. The hyperbaric chamber decompresses under emergency medical situations. It is the definitive treatment for pressure-related diving wounds.