In hyperbaric oxygen therapy, a patient breathes almost pure oxygen
in a pressurized room or tube. By bringing more oxygen into the
bloodstream, the treatment is thought to enhance healing for people
with a number of conditions.
As long ago as 1662, a British clergyman and physician called
Henshaw built the first hyperbaric chamber, a sealed room with a
series of bellows and valves. He believed that using pressure could
help in treating certain respiratory diseases.
Since the 1940s, hyperbaric oxygen treatment (HBOT) has been
standard treatment for military divers in the United States.
Divers who surface too quickly are at risk of decompression sickness
(DCS), sometimes called "the bends," or of an air gas embolism
(AGE). Jointly, these are known as decompression illness (DCI), and
they both relate to problems with air in the body. Consequences can
be severe. HBOT is the primary treatment for both.
Treatment involves early administration of oxygen, and, if
necessary, time spent in a decompression chamber. The diver must
return to the pressure, or "depth," at which they were diving,
followed by gradual decompression. The pressure reduces the volume
of the bubbles.
DCI affects around 1,000 American divers each year, but the uses of
HBOT go beyond the diving community.
More recently, it has been promoted as an alternative therapy for
various conditions, from Alzheimer's disease to infertility.
To meet the growing demand, HBOT chambers have sprung up across a
range of facilities, from hospital outpatient departments to spas.
There are even chambers for home use. Some call it a "miracle cure."
While research suggests that some of these claims may be true, not
all of the suggested uses are approved by the U.S. Food and Drug
Administration (FDA). Concerns have been raised about the risks
associated with "off-label" use of HBOT.
How does hyperbaric oxygen therapy work?
The Undersea and Hyperbaric Medical Society (UHMS) - an
international organization set up in 1967 to encourage cooperation
on diving and undersea medicine - defines HBOT as:
"An intervention in which an individual breathes near 100 percent
oxygen intermittently while inside a hyperbaric chamber that is
pressurized to greater than sea level pressure (1 atmosphere
absolute, or ATA). For clinical purposes, the pressure must equal or
exceed 1.4 ATA [atmosphere absolute] while breathing near 100
percent oxygen."
The body's tissues need oxygen to work. Additional oxygen can help
damaged tissue to heal. Oxygen at high pressure can enhance tissue
function and fight infection, under certain conditions.
At 1.4 ATA, the ambient pressure is three times higher than the air
pressure we normally breathe. Breathing almost pure oxygen at this
pressure can increase the concentration of oxygen available to the
lungs by up to three times.
What are the benefits of HBOT?
Apart from DCI, HBOT is the primary treatment for carbon monoxide
poisoning, and it supports a number of other therapies.
Working with the UHMS, the FDA have approved 13 uses of HBOT.
Evidence has shown that they are safe and effective. Insurance
companies or Medicare will normally cover the cost of treatment.
The approved uses are:
Decompression sickness, experienced by divers and pilots
Acute traumatic ischemia - for example, crush injury
Air or gas embolism
Arterial insufficiencies
Anemia due to severe blood loss
Thermal burns
Carbon monoxide poisoning
Some brain and sinus infections
Intracranial abscess
Gas gangrene
Necrotizing soft tissue infections
Radiation injury - for example, as a result of cancer therapy
Skin grafts.
Wounds and infections that have not responded to other treatment,
such as bone infections and diabetic foot ulcers, have been shown to
respond to HBOT. HBOT has been found to reduce the risk of
amputation in people with diabetic foot ulcers.
How is HBOT delivered?
HBOT is normally provided in an outpatient setting. The number of
visits will depend on the condition.
According to the Mayo Clinic, a person with carbon monoxide
poisoning may need three sessions, while a person with a non-healing
diabetic wound may need 20-40 sessions. An acute condition, such as
DCI, may need only one longer session.
A chamber can hold one or many people, and the patient will probably
wear a mask or hood that delivers oxygen.
In a chamber for one person, the patient usually lies on a table
that slides into a clear plastic tube.
Nowadays, HBOT chambers encourage patients to be comfortable. They
can relax by listening to music or watching TV.
A session can last from 30 minutes to 2 hours, after which the
chamber is slowly decompressed.
What has HBOT not been approved for?
The FDA have expressed concern that HBOT is being used to treat
conditions for which its safety and effectiveness have not been
confirmed.
"Patients may incorrectly believe that these devices have been
proven safe and effective for uses not cleared by FDA, which may
cause them to delay or forgo proven medical therapies. In doing so,
they may experience a lack of improvement and/or worsening of their
existing condition(s)."
Health Benefits of Hyperbaric Oxygen Therapy
Nayan Patel, senior lead reviewer and Intercenter Consult team
leader at the FDA
Diseases and conditions that the FDA believe people may wrongly seek
HBOT for include HIV and AIDS, Alzheimer's and Parkinson's diseases,
asthma, Bell's palsy, cerebral palsy, depression, heart disease,
hepatitis, migraine, multiple sclerosis, sports injury, stroke,
brain injury, and spinal cord injury.
In 2013, responding to a number of complaints, the FDA insisted that
certain conditions should not be treated with HBOT. The Alliance for
Natural Health (ANH) called the announcement a "deceptive
statement."
Those who support the use of HBOT for a wider range of conditions
point out that pressure and additional oxygen can benefit various
bodily functions. They cite a number of studies supporting their
claims.
There are calls for HBOT to be approved as an alternative therapy
for autism, attention deficit hyperactivity disorder (ADHD),
cerebral palsy, and post-traumatic stress disorder (PTSD). There is
strong support in certain circles for its use in helping improve the
quality of life of veterans.
Clinical trials have been investigating the effect of HBOT on
traumatic brain injury (TBI).
It is believed that HBOT can help to heal brain injury by improving
the way dormant neurons function and stimulating the growth of
axons. A meta-analysis published in May 2016 suggests that HBOT can
enhance a patient's score on the Glasgow Coma Scale, but no
significant change was seen in the PTSD score.
Dr. Paul Harch, hyperbaric medicine, diving, and emergency medicine
physician, and coauthor of the book The Oxygen Revolution calls for
wider approval of the uses of HBOT, and especially for TBI and
neurological disorders.
Dr. Harch told Medical News Today:
"It was found that diseases and disorders with similar disease
processes responded similarly to HBOT. In Russia nearly 100
diagnoses are treated and nearly 70 in China. We have been much more
restricted in the U.S. based on reimbursement considerations."
The UHMA note that "meticulous scrutiny" is needed before new
applications of HBOT can be approved for use in treating a
condition. Each case involves a stringent review of a wide range of
research by an interdisciplinary team.
More research is needed before the requested new uses can be
implemented, say the FDA and the UHMA.
What are the risks of HBOT?
High atmospheric pressure can damage the ear. Middle ear barotrauma
affected 2 percent of 1,446 participants in one study. A higher
incidence of Eustachian tube dysfunction, up to 45 percent, has been
detected using sensitive testing equipment.
Sinus pain can affect people with upper respiratory tract infections
or allergic rhinitis. People who have recently had a cold or fever
should not undergo HBOT.
People with certain lung diseases or an airway obstruction may be at
risk of pulmonary barotrauma and damage to the lungs as a result of
air becoming trapped during decompression. The result could be a
collapsed lung or an air embolism. Long-term treatment could
compromise lung function.
Those with existing cardiovascular problems should be monitored for
acute pulmonary edema or an embolism. Symptoms include joint pain
and paralysis.
Some patients may experience confinement anxiety, or claustrophobia,
during treatment. Myopia has been reported following HBOT.
Overexposure to oxygen at high pressure can lead to oxygen
poisoning. When a person uses oxygen, highly reactive byproducts are
released. At high pressure, these build up, saturating tissues and
possibly leading to convulsions and other adverse effects.
Dr. Harch told MNT that some people, for example, those with seizure
disorders should be treated by "medical professionals who have
knowledge, experience, and hopefully training in the field."
"The more underlying medical problems one has (e.g., diabetes, high
blood pressure, lung disease, etc.) the more you want to be
evaluated and treated by medical professionals."
Dr. Paul G. Harch
HBOT is not recommended for people who have undergone recent ear
surgery or trauma.
A growing trend brings growing concerns
In January 2015, the Wall Street Journal reported that growing
numbers of people are seeking out HBOT as a solution to problems
that conventional medicine seems unable to resolve. In 2010, 20,000
Medicare beneficiaries had FDA-approved treatments using HBOT, up 24
percent from 2008.
Johns Hopkins Medicine urge caution in the choice of treatment
setting. HBOT should only be carried out in a hospital, they say,
with trained medical staff.
HBOT Cerebral Palsy Benefits
If Medicare and insurance do not cover the treatment, it may be
because it has not yet been approved as safe and effective.
The WSJ point out that since not all the claims for HBOT are
conclusively supported by evidence, people who seek unapproved
treatments from small clinics and spas may be wasting their money.
It is important for people to understand that HBOT is not a "magic
bullet."
Non-hospital use may include "soft" or "mild" chambers that cannot
sustain the necessary pressure, or guarantee the purity of the
oxygen. As a result, the patient may undergo many treatments without
seeing any benefit.
If the power is disrupted, the chamber could deflate, leading to
suffocation. These chambers are not considered appropriate by many
hyperbaric practitioners.
Since pure oxygen is highly explosive and flammable, a number of
explosions have been reported.
HBOT may yet turn out to be a miracle cure. But, as with all health
choices, it pays to be cautious.
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