Forecast, June 1993 v46 n6 p57(5)
Title: Hyperbaric oxygen therapy for foot ulcers. (includes related
Authors: Cianci, Paul; McCarren, Marie)
Subjects: Diabetes Complications)
Ulcers Care and treatment)
Hyperbaric oxygenation Therapeutic use)
Reference #: A13917295)
Full Text COPYRIGHT American Diabetes Association Inc. 1993)
breath. The air you just took in is about 21 percent oxygen. The
capillaries in your lungs pick up the oxygen, and it's dissolved in the
plasma of your blood and gets carried to all parts of your body. Your
body uses that oxygen to heal itself, and 21 percent oxygen is usually
plenty to do the job. When you have a foot ulcer, however, your body
could use even more oxygen. The white blood cells that fight the
infection in the ulcer use 20 times more oxygen when they're killing
bacteria. Also, the more oxygen your body has to work with, the more
efficiently it lays down wound-repairing connective tissue.
when you need more oxygen, you may have less. If you have neuropathy
(diabetic nerve damage), that may cause changes in blood flow, resulting
in islands of low oxygen levels in your foot. Less oxygen means slower
healing, and an ulcer that doesn't heal could eventually lead to an
amputation. So it seems that you should try to get extra oxygen in your
blood when you have a foot ulcer, to bring the oxygen levels in the
tissues around the ulcer up to normal, or even higher.
sitting in your living room and breathing in 100 percent oxygen won't do
the trick. Under normal circumstances, only so much oxygen will dissolve
in your blood. It's like trying to dissolve salt in water. When you pour
a spoonful of salt into a glass of cold water, not all of the salt
dissolves. Simply adding more salt doesn't make the water dissolve more
salt. But when you pour a spoonful of salt into a glass of hot water,
all the salt dissolves. At higher temperatures, more salt dissolves.
What temperature does for salt in water, pressure does for oxygen in
blood. At higher pressures, more oxygen dissolves.
Breathe Deep—In A Way
make more oxygen dissolve in your blood by going into a pressurized
chamber and breathing 100 percent oxygen. This is called hyperbaric
oxygen therapy. (Hyper means high, baric means barometric, or
atmospheric, pressure.) The pressure in a hyperbaric chamber is the same
as if you went scuba diving 33 feet under water. When you breathe 100
percent oxygen while you're at that pressure, your blood has about 15
times more oxygen dissolved in it than it does normally.
Hyperbaric oxygen (HBO) therapy isn't a new treatment. The technology
was developed in the late 1800s and was first used to treat
decompression sickness ("the bends") in deep-sea divers who swam up to
the surface too fast. Today, HBO is also used to treat carbon monoxide
poisoning, serious burns, and radiation damage—all conditions in which
not enough oxygen is getting to the tissues.
studies have suggested that hyperbaric oxygen therapy is effective, when
used with other therapies, in treating diabetic foot ulcers and
preventing amputations due to ulcers. But HBO therapy isn't magic. It
won't work unless it's part of an aggressive team approach. To get your
ulcer to heal, you will need tight blood glucose control, aggressive
removal of dead tissue, infection control, correction of circulation
problems, good nutrition, and, possibly, hyperbaric oxygen therapy.
centers have walk-in chambers. You sit or recline in an air-pressurized
chamber, possibly with one or more people, while you breathe oxygen
through a mask or head tent. At other centers, you will lie in a
one-person chamber, and the entire chamber is pressurized and filled
with oxygen. But even in a chamber of this type, it is the inhaled
oxygen, which is then absorbed by your blood after you breathe it, that
speeds wound healing, not the oxygen drifting past the wound. (You may
have seen advertisements for devices that encase a person's leg and
deliver oxygen to the skin. This is not hyperbaric oxygen therapy, and
it's not effective—your skin doesn't absorb oxygen that way. These
devices may even reduce the amount of oxygen that gets to your leg.)
ulcer is not infected, treatment once a day for two hours is enough to
stimulate healing. You can do this as an outpatient.
if your ulcer is infected and there is a high risk of amputation, you
will need treatment twice a day for 90 minutes. Usually, treatments will
continue for three to four weeks. In most cases, you'll have to be
hospitalized and be put on antibiotics. If you take insulin, your doctor
may need to change your dose while you are in treatment. The average
cost for an entire course of treatment is $8,000. Medicare and insurance
companies cover HBO treatments when they are used as part of an
aggressive program of wound management.
Effects Of Hyperbaric Oxygen Therapy
levels remain high in tissues for several hours after a treatment, which
encourages capillary growth. New capillaries mean more blood gets to the
site of the ulcer, which speeds healing. High oxygen levels also make
red blood cells more flexible so they can get through the twists and
turns of the capillaries and get to where they're needed.
high doses of oxygen can produce a reduction in blood flow to normal
tissue, this effect is more than made up for by the 10- to 15- fold
increase in the amount of oxygen dissolved in the plasma. And sometimes
you want less flow—as long as the flow is rich in oxygen—such as when
your foot is already swollen.
are, however, some side effects of HBO therapy.
effects due to pressure
the pressure changes, your ears will pop, as they do when you fly in an
airplane or drive in the mountains. If your ears can't equalize the
pressure, such as when you are congested with a cold or hay fever, your
ears or sinuses could be damaged. Therefore, you shouldn't have
treatments when you are congested. Some people with chronic ear trouble
may need to use ear tubes to continue therapy. These are surgically
inserted but not permanent.
can suffer a collapsed lung during treatment. Lung problems are very
rare, occurring in about 1 in 50,000 treatments. You will need special
consultation and medical clearance if you have active asthma, emphysema,
or other lung problems that would put you at high risk for problems.
Older people sometimes find that, after treatment, their vision
improves, and they can read fine print better. Unfortunately, this
effect lasts only a few weeks.
a drug with definite overdose and toxic effects, usually affecting the
central nervous system or lungs. Long exposure to high doses of oxygen
under pressure can cause grand mal seizures. This happens in about 1 in
10,000 treatments and is reversed by stopping HBO treatment. Therapy can
continue after the seizure stops. Susceptibility varies widely, but as
oxygen in the blood goes up, so does the risk of oxygen seizures. For
this reason, oxygen seizures. For this reason, oxygen treatments are
limited to a maximum depth equal to diving 66 feet under water. Fever
and certain medications can predispose you to oxygen seizures, so tell
your doctor what drugs you are taking.
oxygen levels can cause irritation of the lung tissue, but treatment
schedules have been refined, and this complication is virtually unheard
of in the United States today.
HBO treatments take place in closed chambers, some people get anxious.
Sedation can help, but some patients can't tolerate treatment because of
Hyperbaric oxygen therapy is not for everyone. Before you start HBO
treatments, you will be assessed by a doctor specially trained in diving
and hyperbaric medicine to see if HBO therapy is right for you.
good blood flow in the arteries of your feet for HBO therapy to be
effective. If the doctor finds that you have reduced arterial blood
flow, you will be referred to a vascular specialist. Correcting the
vascular specialist. Correcting the vascular problem may solve the ulcer
problem without HBO treatments.
recommend hyperbaric oxygen treatment for trivial ulcers that are likely
to respond to more traditional therapy. We use HBO therapy on patients
with deep ulcers that have gone into the connective tissue or bone, or
who have infections or gangrene (dead tissue) and where loss of a limb
is a possibility.
Do I Go?
over 400 hyperbaric oxygen therapy centers throughout the United States
and Canada. Most are in hospitals, and many of these are associated with
universities. They are staffed by specially trained doctors, nurses, and
technicians. The Undersea and Hyperbaric Medical Society (9650 Rockville
Pike, Bethesda, MD 20814) is an international scientific organization
and the leading authority for hyperbaric medicine in the United States.
They can tell you of a program near you.