Hyperbaric Therapy for CO Poisoning and Decompression Sickness
Hyperbaric oxygen therapy has helped treat a variety of illnesses. Over the years,
research has shown that it can treat many conditions that involve oxygen-starved tissue.
You can get hyperbaric oxygen therapy in either a single-person chamber or tube, or
a larger chamber that holds several people at a time. The chamber is then pumped full
of pure oxygen, and the pressure rises to 2.5 times that of normal air pressure.
The FDA has approved the therapy for several conditions, ranging from severe gangrene
to certain infections, burns, radiation injury, and crush injuries. Of these conditions,
the two that perhaps best show the treatment's lifesaving potential are carbon monoxide
poisoning and decompression sickness.
Carbon monoxide poisoning
Carbon monoxide poisoning is caused by exposure to a colorless, odorless, tasteless
gas known as carbon monoxide (CO). CO is found in combustion fumes. CO poisoning is
usually caused by car or truck exhaust, wood stoves, and other fuel burning appliances, smoke
from a fire or blocked fireplaces, nonelectric heaters, malfunctioning gas appliances,
and faulty heating exhaust systems in the home or garage.
Known as a silent killer, CO displaces the oxygen in the bloodstream when the CO is
mixed in the normal air you breathe. If a heater's combustion system malfunctions
and CO seeps out of it, for example, the gas can kill people while they are asleep.
CO poisoning typically occurs at home, in a garage or car, or in another enclosed
space like a camper, trailer, or tent.
Everyone is at risk for CO poisoning from combustion fumes, especially during the
winter when windows are closed. Some people are more susceptible than others. These
include babies, pregnant women, and people with heart problems, breathing problems,
How CO poisoning is treated
CO poisoning is a medical emergency. Its main symptoms are headache (most common),
nausea, dizziness, vomiting, weakness, chest pain, and confusion. More severe CO poisoning
leads to loss of consciousness and death.
The first step is to get out of the area where CO gas is present (or suspected) and
get to the hospital. If an ambulance or emergency medical team arrives, medical personnel
will likely use a face mask to give pure oxygen. This is the most common treatment
for CO poisoning. The face mask is generally used for about 4 hours. If person poisoned
has trouble breathing on his or her own, hospital staff may hook the person up to
a machine that helps him or her breathe.
CO poisoning: Why hyperbaric oxygen therapy is prescribed
Although CO poisoning in many people can be reversed without hyperbaric oxygen therapy,
long-term damage from CO poisoning can include harm to the central nervous system
and the cardiovascular system. Several studies have shown that under certain conditions,
hyperbaric oxygen therapy can cut the risk for brain injury and nerve damage.
One drawback is that many hospitals do not have a hyperbaric chamber. So, you may
be transferred by ambulance or helicopter to a hospital that has one. Hyperbaric therapy
is also more expensive than using the face mask to deliver oxygen.
Decompression sickness (DCS) is a rare condition that can occur in deep sea divers,
aviators, miners, astronauts, mountain climbers, or people who work at high or low
altitudes. It often occurs as people return quickly to a normal altitude from these
heights or depths.
DCS happens when bubbles of nitrogen and other gases form in the bloodstream. The
bubbles 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 headaches, dizziness, extreme fatigue, ringing in the
ears, visual problems, chest pain and shortness of breath, a skin rash and itching,
and malaise. Warning signs can also include numbness, paralysis, staggering, coughing
up blood, and collapse. In rare cases, people with DCS can go into shock and die if
Divers using compressed air are at particular risk for decompression sickness, especially
if they come to the surface too quickly. Those who are older, heavier, or less physically
active run a higher risk.
DCS: Why hyperbaric oxygen therapy is prescribed
Hyperbaric oxygen therapy is the primary treatment for DCS. It immediately reduces
the amount of bubbles in the bloodstream, fills the tissues with oxygen, and reduces
In most instances, it's critical 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 seek medical attention and possibly
receive the therapy to prevent long-term damage.
Side effects of hyperbaric therapy
Typically, the hyperbaric therapy treatments for CO poisoning or DCS last for a few
hours and may need to be repeated. The treatments are generally free of side effects,
but side effects do sometimes occur. For example, some people's ears pop or they have
mild discomfort in the chamber. These can be eased as the pressure is lowered. Some
feel lightheaded when leaving the chamber. Others may have nearsightedness that usually
gets better within days to weeks after the last treatment. According to experts, undergoing
hyperbaric oxygen therapy at a hospital with trained staff is the best way to avoid
more serious side effects.