Definition & Overview
Hyperbaric oxygen therapy (HBOT) is used to increase a person’s blood oxygen levels. It is the primary treatment for decompression sickness (DCS). It is also used as a complementary treatment for many diseases and medical conditions. These include burns, brain abscess, and non-healing wounds.
HBOT is known to improve treatment outcomes because it speeds up wound healing. It also promotes the growth of new blood vessels and cell regeneration. It also helps fight infections and reduce swelling.
Who Should Undergo & Expected Results
The US Food and Drug Administration (FDA) has approved the use of HBOT for the treatment of:
Arterial gas embolism - This refers to gas bubbles in blood vessels. They can form due to rapid decrease in pressure. These bubbles can be fatal. They can block an artery and cut off blood supply to vital organs, such as the brain and the lungs. If treated early with HBOT, patients can reduce their risk of stroke and heart attack.
Brain abscess - Patients treated for brain abscess can also benefit from HBOT. The therapy can speed up the healing of damaged brain tissue.
Burns - HBOT stimulates wound healing in burn victims. This helps them avoid tissue death. HBOT decreases the risk of infection. It also enhances the effects of antibiotics.
Carbon monoxide (CO) poisoning - CO is a clear and odourless gas. When inhaled, it enters the bloodstream. It then mixes with the part of red blood cells that carries oxygen throughout the body. This affects the blood’s ability to carry oxygen.
Gangrene, radiation injuries, diabetic foot ulcer, and severe anaemia - These can cause the cells and tissues to fail and die. HBOT helps treat these conditions by increasing blood flow and supply of oxygen to the affected areas of the body. In patients with non-healing wounds, HBOT can reduce the risk of amputation.
Sudden deafness and vision loss - HBOT can be used if sudden vision or hearing loss is due to poor blood supply to the eyes or ears.
There is not enough evidence to support that HBOT is also effective in treating other medical conditions not mentioned above. These include AIDS or HIV, stroke, and heart disease. It is also not approved by the US FDA for the treatment of any form of cancer, depression, and cerebral palsy.
How Does the Procedure Work?
HBOT is an outpatient procedure. Each session takes about two hours. The total number of sessions depends on the condition. The more severe the disease, the more sessions the patient needs. For example, patients with non-healing wounds due to diabetes may require as many as 40 sessions.
HBOT involves breathing 100% oxygen in an enclosed pressure chamber. The chamber can be a monoplace made of clear acrylic (can hold one person at a time) or a multiperson HBOT room. In an individual unit, the person lies down on a table that fits inside the chamber. In a multiperson HBOT room, on the other hand, patients have the option to sit or lie down. The oxygen is delivered through a mask or clear hood placed over the patient’s head. The atmospheric pressure in the chamber is up to three times higher than normal. Patients are monitored by members of their healthcare team while inside the chamber.
Only clean cotton clothing is allowed inside the HBOT chamber. Electronic devices, hair products, and perfumes are not permitted. For patient’s safety, they must inform their doctor if they are taking any drugs. They are also advised not to smoke during the treatment period. Smoking affects the body’s ability to transport oxygen.
Other details that patients must tell their doctors prior to the therapy are:
If they might be pregnant.
If they have chest or sinus congestion.
If they have skipped a meal before the therapy. Two hours in the HBOT chamber can make a person really hungry.
If they are anxious about the therapy.
Possible Complications and Risks
HBOT is a safe procedure with only minor risks. The most common is barotrauma. This is an injury to the ears caused by sudden change in air pressure. This can cause dizziness, slight hearing loss, and general discomfort. In many cases, it resolves when a person chews gums or yawns. Doing breathing exercises may also help. Barotrauma can also affect the lungs. When it does, it increases the risk of lung tissue damage.
Bennett MH, et al. Hyperbaric oxygen therapy for acute ischaemic stroke. Cochrane Database of Systematic Reviews. http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD004954.pub2/abstract.
Murad MH, et al. Using GRADE for evaluating the quality of evidence in hyperbaric oxygen therapy clarifies evidence limitations. Journal of Clinical Epidemiology. 2014;67:65.
Dauwe PB, et al. Does hyperbaric oxygen therapy work in facilitating acute wound healing: A systematic review. Plastic & Reconstructive Surgery Journal. 2014;133:208e.