Hyperbaric chamber therapy, otherwise known as hyperbaric oxygen therapy (HBOT), is a medical treatment used to help boost the body’s natural healing processes.
Historically, hyperbaric oxygen therapy was first used in the U.S. in the early 1900s. Later, it was used to treat decompression sickness, a hazard of scuba diving. Today, HBOT is prescribed and supervised medically by institutions such as Mayo Clinic, and it may even be covered by insurance (depending on the condition it’s used to treat).
Explore how exactly hyperbaric chambers work, and what type of ailments HBOT is commonly used to treat. Are they controversial, and perhaps most importantly, what does the research say about its efficacy and safety?
How Does HBOT Work?
One method of HBOT involves a person receiving the treatment inside of a tube-like chamber. Some tubes are made of clear acrylic, allowing patients to see outside of the chamber. This transparency may eliminate some of the potential anxiety a person may have of feeling trapped inside the tube.
During HBOT, a patient is instructed to lie down in the enclosed chamber and breathe the air inside the tube as the pressure is gradually increased.
Another mode of treatment, such as that offered at Mayo Clinic, is a multiperson hyperbaric oxygen room, where oxygen is delivered via a mask or a lightweight clear hood placed over the head. In this scenario, a person can sit or lie down in a lounge chair—there is no tube or chamber with this method.
There is no way of controlling how much oxygen gets absorbed into the body. HBOT is a way to hypothetically turn up the volume of oxygen absorption by increasing the atmospheric pressure. The pressure inside the chamber is normally two to three times greater than outside air pressure, which means patients are inhaling 100% oxygen.
Hyperbaric chambers work by providing oxygen that can be controlled. Normally, oxygen is transported throughout the body—after it initially gets absorbed by the lungs—then circulates to all the tissues and organs via the heart and blood vessels.
HBOT allows for oxygen to be dissolved in the blood, body fluids, cerebral spinal fluid (the fluid that surrounds the brain and spinal column), bone tissue, and lymph node. Oxygen-rich fluids in the body can then travel to areas where blood circulation is blocked.
- Helping the immune cells of the body to kill bacteria
- Reducing inflammation
- Allowing for collateral circulation (growth of new blood vessels to provide extra oxygen to affected areas of the body)
The body needs oxygen to heal itself. Many injuries and illnesses involve the lack of oxygen-rich blood, which is then unable to travel to affected areas of the body.
For example, diabetes can result in poor and slowed circulation, making it more difficult for oxygen-rich red blood cells to reach wounded areas of the skin. This results in injuries that are very slow to heal or injuries that do not heal at all.
HBOT has been used to treat many different medical conditions and injuries that benefit from having an increased level of oxygen in the tissues. Hyperbaric oxygen therapy can be utilized as a stand-alone treatment or a procedure that can boost the action of medicine, such as antibiotics.
Some of the common uses for HBOT that are often covered by insurance include:
- Arterial gas embolism (air bubbles in the blood vessels)
- Carbon monoxide poisoning (from breathing noxious fumes)
- Cyanide poisoning
- Decompression sickness (a common scuba diving condition, also called "the bends")
- Specific types of non-healing wounds such as diabetic wounds
- Gas gangrene (fast-spreading gangrene in infected wounds that gives off a foul-smelling gas)
- Intracranial abscess (originating from an ear infection, sinus infection, or another primary source of infection)
- Tissue damage from radiation therapy
- Osteomyelitis (long-term inflammation of bone or bone marrow)
- Compromised skin grafts or flaps
- Severe anemia
- Brain abscess
- Crushing injury
- Sudden deafness
- Sudden, painless vision loss
There are several other types of injuries and illnesses that are said to benefit from HBOT, but there is a lack of clinical research evidence to back up many of these claims. Therefore, these conditions are not usually covered by insurance:
- Lyme Disease
- Near drowning
- Recovery from plastic surgery
- Alzheimer's disease
- Bell's palsy
- Brain injury
- Cerebral palsy
- Chronic fatigue syndrome
- Gastrointestinal ulcers
- Heart disease
- Multiple sclerosis
- Parkinson's disease
- Spinal cord injury
- Sports injury
- Traumatic brain injury
Although hyperbaric chamber treatment is considered a natural and relatively safe mode of therapy, there are some side effects involved.
These include problems with the sinuses and ears (such as popping in the ears) due to the sudden changes in atmospheric pressure, fluid buildup or rupture in the middle ear, temporary changes in vision causing nearsightedness, lung collapse (called barotrauma) from air pressure changes, and oxygen toxicity (a side effect from receiving excessively high concentrations of oxygen).
Oxygen poisoning can cause lung failure, fluid in the lungs, or seizures. According to Johns Hopkins Medicine’s Health Library, taking frequent breaks to breathe regular air during HBOT can help prevent oxygen poisoning.2
Another hazard of HBOT is fire. Pure oxygen can cause a spark to easily ignite into flames. Therefore, in preparation for HBOT, it’s important not to have any lighters or battery-powered devices in the treatment area.
Eliminating petroleum-based or flammable skincare or hair products from your body is also important.
The side effects of HBOT are usually mild and temporary, provided some safety measures are followed. These safety measures include that the therapy is administered for no longer than two hours in duration per session and that the pressure inside the chamber is less than three times that of the pressure in the atmosphere.
Do not consider having HBOT with these conditions:
- Lung conditions (because of the increased risk for a collapsed lung)
- A cold
- A fever
- A recent ear surgery
- A recent injury
- Claustrophobia (fear of small spaces)
Before treatment, it’s important to shower and avoid all perfumes, deodorants, hair sprays (and styling products). Wigs and jewelry are not allowed inside the chamber. Alcohol and carbonated drinks should be avoided for at least four hours before HBOT.
Smokers are encouraged to quit smoking during the time span that they receive therapy because tobacco products block the body’s natural ability to transport oxygen.
To minimize problems with ears and sinuses, techniques (such as yawning or swallowing) are taught for adequate clearing of the ears. Sometimes tubes are inserted into the ears to minimize issues that result from pressure in the ears during HBOT.
The following are questions that healthcare professionals commonly ask before treatment:
- Do you have any cold, nasal congestion, or flu symptoms?
- Do you have a fever?
- Are you pregnant?
- Have you eaten prior to treatment?
- If you have diabetes, did you take your insulin before treatment?
- Has there been any recent change in your medications?
- Do you have anxiety?
Once HBOT is completed, there are no activity or dietary limitations that follow.
There have been research findings from clinical research studies on the safety and effectiveness of hyperbaric chambers for various maladies.
Skin Grafts and Flaps
One study examined the efficacy of HBOT used to treat tissue grafts and flaps.3 The findings concluded that HBOT can "increase the likelihood of composite graft survival, improve skin graft outcomes, and enhance flap survival."
The study authors also explain that HBOT is “not indicated for healthy, non-compromised tissue, but is a valuable salvage adjunct in the treatment of threatened grafts and flaps."
Traumatic Brain Injury
In human studies involving those with severe traumatic brain injury (TBI), HBOT was deemed a “promising, safe, therapeutic strategy for severe TBI patients."4 Note, this does not mean that there is clear evidence that HBOT is effective for traumatic brain injuries—more research studies are needed in this area.
In one report by the United States Government Accountability Office, three article reviews found that HBO therapy was safe.5
Cerebral Palsy (CP)
Although HBOT has been touted as one of the most effective procedures for cerebral palsy, one double-blind placebo study (the gold standard of clinical research studies) discovered that HBOT was no different than pressurized air for kids with CP.6
According to Dan Rose, M.D., in an American Family Physician journal entry, “Hyperbaric oxygen therapy (HBOT) is associated with remission rates [a period during which symptoms of disease are reduced or disappear] of 81 to 85 percent at two to three years in patients with chronic refractory osteomyelitis.”7
Chronic refractory osteomyelitis is an infection in the bone that lasts longer than six months (regardless of antibiotic therapy and other appropriate medical treatment).