Hyperbaric Oxygen Therapy (HBOT) for CO Poisoning and Decompression Sickness
Hyperbaric oxygen therapy (HBOT) can help treat a variety of illnesses. Research has
shown that it can treat many conditions that cause oxygen-starved tissue.
You can get HBOT in a single-person chamber or tube. Or it may be done in a larger
chamber that holds several people at a time. The chamber is pumped full of pure oxygen.
The pressure rises to 2.5 times that of normal air pressure.
The FDA has approved HBOT for several conditions. These include severe gangrene, some
infections, burns, radiation injury, and crush injuries. It's also used for carbon
monoxide poisoning and decompression sickness. When used for either of these, the
treatment can save a person’s life.
What is carbon monoxide (CO) poisoning?
Carbon monoxide (CO) is a colorless, odorless, tasteless gas. CO is found in combustion
fumes. CO poisoning is usually caused by car or truck exhaust, wood stoves, and other
fuel burning appliances. It can be caused by any of these:
CO is known as a silent killer. It displaces the oxygen in the bloodstream when the
CO is mixed in the normal air you breathe. If a heater's combustion system fails and
CO seeps out of it, the gas can kill people while they are asleep. CO poisoning can
Any person is at risk for CO poisoning from combustion fumes. The risk is higher during
the winter when windows are closed. Some people are more at risk than others. These
How CO poisoning is treated
CO poisoning is a medical emergency. Its main symptoms are:
Headache (most common)
More severe CO poisoning leads to loss of consciousness and death.
Get out of the area where CO gas is present or suspected. Call 911. The emergency medical team will likely use a face mask to give pure oxygen. This
is the most common treatment for CO poisoning. The face mask is used for about 4 hours.
If the person has trouble breathing on their own, they may be put on a machine that
helps them breathe.
Hyperbaric oxygen therapy (HBOT) for CO poisoning
CO poisoning in many people can be reversed without HBOT. But studies have shown that
in some cases, HBOT can lower the risk for brain injury and nerve damage. HBOT is
often advised for pregnant people with high levels of carbon monoxide.
Many hospitals do not have a hyperbaric chamber. The person may be sent by ambulance
or helicopter to a hospital that has one. HBOT is more expensive than a face mask
to deliver oxygen.
What is decompression sickness (DCS)?
Decompression sickness (DCS) is when bubbles of nitrogen and other gases form in the
bloodstream. It is a rare condition that can happen in:
It can happen as a person returns quickly to a normal altitude from these heights
The nitrogen bubbles in the blood can cause dangerous symptoms throughout the body.
The most common symptom is extreme, crippling joint pain at the shoulders, knees,
elbows, and ankles. This pain is often referred to as the bends.
People with DCS may also have:
Ringing in the ears
Shortness of breath
Skin rash and itching
Coughing up blood
In rare cases, people with DCS can go into shock and die if not treated.
Divers using compressed air are at high risk for DCS. DCS can happen if they come
to the surface too quickly. People who are older, heavier, or less physically active
have a higher risk.
Hyperbaric oxygen therapy (HBOT) for DCS
HBOT is the main treatment for DCS. The therapy:
Instantly reduces the amount of nitrogen bubbles in the bloodstream
Fills body tissues with oxygen
Reduces dangerous swelling
In most cases, it's vital to get treatment as soon as possible, because the symptoms
of DCS can be life-threatening. Even if your symptoms disappear when you return to
a normal altitude, you should still get medical attention and possibly have HBOT to
prevent long-term damage.
Side effects of hyperbaric oxygen therapy
HBOT lasts for a few hours. It may need to be repeated. The treatment may have side
effects in some people. For example:
Your ears may pop or you have mild discomfort in the chamber. These can be eased as
the pressure is lowered.
You may feel lightheaded when leaving the chamber.
You may have nearsightedness after treatment. This usually gets better within days
to weeks after the last treatment.
In rare cases, a person may have an eardrum rupture, lung symptoms, or a seizure.
Having HBOT at a hospital with trained staff is the best way to prevent serious side