Drowning is the leading cause of injury-related deaths among U.S. children. Every
year, an estimated 5,000 youngsters age 14 and under are
hospitalized due to unintentional drowning-related incidents.
Fifteen percent die in the hospital, and as many as 20 percent suffer severe,
permanent, neurological disability, according to the National
Typically, near-drowning victims undergo traditional medical treatments. But
there is a promising treatment that’s less well-known among
aquatics professionals and doctors: hyperbaric oxygen therapy.
Commonly called HBOT, this comfortable, noninvasive treatment uses 100 percent
medical grade oxygen at increased atmospheric pressure to enhance
oxygen delivery to areas of the central nervous system with poor or
compromised circulation. The treatments are delivered inside a
pressurized chamber. HBOT is not a new therapy. It has been widely
accepted for treatment of scuba diving injuries for more than 100 years.
The physiology of HBOT is explained by chemistry gas laws. The laws of Boyle,
Charles, Henry and Guy-Lussac illustrate how increasing the
concentration of inhaled oxygen and increasing the ambient pressure
will cause gas to dissolve into body fluids and tissue in direct
proportion to the change in concentration and pressure. The air we
breathe contains 21 percent oxygen. A monoplace chamber uses 100
percent oxygen. The hyperbaric chamber is used to increase the
ambient pressure oxygen resulting in overall increased body tissue concentrations.
In drowning survivors, prolonged submersion results in tissue hypoxemia and
acidosis. The degree of hypoxemia and acidosis determine the amount
of damage to the central nervous system. Hypoxemia causes
microcirculatory disturbances, including swelling and ionic changes
in the blood vessels; red blood cells clump and are unable to pass
through capillaries. This creates areas in the brain where neurons
have compromised blood flow and diminished oxygen delivery. Though
the neurons are viable, they are not functioning properly due to
diminished oxygen delivery. These areas are referred to as the
ischemic penumbra. The penumbra is the area of focus for hyperbaric oxygen treatment.
In a hyperbaric environment, oxygen delivery is enhanced and carried through the
plasma to viable, nonfiring neurons in the penumbra. It is
theorized that decreased brain swelling, new capillary growth and
improvements in metabolism facilitated by oxygen result in
clinically observed improvement in the patient treated with HBOT.
Many facilities throughout the United States are treating children with chronic
anoxic brain injuries. When choosing a facility for treatment,
it’s important to find a site with a physician trained in
hyperbaric medicine through a course approved by the Undersea
Hyperbaric Medical Society. The staff should be certified to
operate hyperbaric chambers through the National Board of Diving
and Hyperbaric Medical Technology, and have documented clinical
experience with HBOT and neurological indications. The chambers
should be certified and stamped by the American Society of
Mechanical Engineers/ Pressure Vessels for Human Occupancy.
Hyperbaric oxygen is considered a therapy, not a cure, for anoxic brain injury. It
should be seen and utilized as an additional therapeutic modality
for brain injury patients already receiving traditional therapies
such as physical, occupational, speech and the like. The most
obvious improvements are seen in patients with hypotonia,
hypertonia, cognitive deficits and impaired vision.
This therapy can be helpful, but it is not for everyone. There are known risks and side
effects associated with hyperbaric oxygen. Most are similar to the
potential side effects of recreational scuba diving, including
barotrauma affecting the eardrum, sinuses or lungs. An overdose of
oxygen for a prolonged period of time can result in oxygen
toxicity, which manifests as seizures.
Due to the pressurized pure oxygen environment, the chamber is susceptible to
fire hazard if the proper precautions and training are not taken by
the facility administering the therapy.
Currently, the FDA has 14 approved indications for HBOT. These include scuba injuries
such as “the bends,” diabetic foot ulcers and carbon
monoxide poisoning. Anoxic brain injury, including drowning
injuries at this time, is considered an “off-label”
indication for HBOT.
Major medical insurance frequently covers treatments based on whether a therapy
has obtained FDA approval. Generally, HBOT for treatment of anoxic
brain injury is not covered by standard medical insurance.