What is HBOT?
Hyperbaric Oxygen
Therapy is a method of administering pure oxygen at greater than atmospheric
pressure to a patient in order to improve or correct conditions. Providing pure
oxygen in a pressurized chamber we are able to deliver 10-15 times more oxygen
than if delivered at sea level or at normal atmospheric pressures.
Why does HBOT help speed the healing process?
Nature has dictated that healing cannot take
place without appropriate oxygen levels in the body’s tissues. In many cases,
such as those involving circulatory problems caused by things like diabetes, strokes, anoxic brain injury, and
near drowning just to name a few, adequate oxygen cannot reach the injured area
and therefore the body’s natural healing process fails to function properly.
Oxygen given with increased pressure can correct many serious health problems.
To provide this increased pressure one must be within a pressurized room, a
Hyperbaric Oxygen Chamber. Oxygen, given at normal atmospheric pressure is
insufficient to raise tissue oxygen levels significantly above normal. The answer is to deliver oxygen with
a slight increase in pressure with a chamber, thereby causing the oxygen to go
into solution in the plasma and tissues, raising oxygen levels significantly
above that which can be achieved at normal pressure.
Why is Oxygen so important?
Oxygen
is a colorless, odorless gas that makes up about 21 percent of the atmosphere.
It is essential to life for two reasons:
-
Oxygen is one of the body’s basic
building blocks. All of the body’s major components, water, protein,
carbohydrate, and fat contain oxygen.
-
Oxygen helps bring about certain chemical
reactions within the body that result in energy production. Energy is
needed for functions such as circulation, respiration, and digestion. Energy
is also used to maintain a constant body temperature.
If the body is totally deprived of
Oxygen, death results within minutes. A diminished supply of oxygen causes
multiple symptoms, some of which are mental disturbances, shortness of breath,
and rapid pulse, a fall in blood pressure and cyanosis, a blueness of the skin
and mucous membranes. This results in a marked reduction in all bodily
functions. This condition is known as hypoxia, or under-oxygenation of the
tissues.
How does HBOT allow more Oxygen to be absorbed into the bloodstream and
tissues?
Blood is made up of three
main components: white cells that fight infection, red blood cells that carry
oxygen, and plasma, the fluid that carries both kinds of cells throughout the
body. Under normal circumstances, only the red blood cells carry oxygen.
However, because HBOT allows more oxygen into the body under pressure, Oxygen
dissolves into all of the body’s fluids, including the plasma, the lymphatic
fluids, and the cerebrospinal fluids surrounding the brain and spinal cord.
These fluids can carry the extra oxygen even to areas where circulation is poor
or blocked, either by trickling past the blockages or by seeping into the
affected area.
This extra oxygen helps in the healing process and enhances the white blood
cells’ ability to fight infection. It can promote the development of New
Capillaries, the tiny blood vessels that connect arteries to veins. It also
helps the body build new connective tissue. In addition, HBOT helps the organs
function in a normal manner.
As we age, we can lose vital lung capacity and the ability to effectively obtain
adequate Oxygen. Some disease conditions impair oxygen utilization. In addition,
with injuries or conditions where there is swelling or edema, this causes
pressure within the tissue, which cuts off circulation flow.
For years, conventional medicine thought of HBOT only as a treatment for
decompression sickness........
However, this is about to change the scope of medicine as never before. The Use
of HBOT is becoming increasingly common in general practice as more doctors
become acquainted with new applications. Doctors now realize that HBOT has other
uses, including the treatment of non-healing wounds, Carbon Monoxide poisoning,
various infections, damage caused by radiation treatments, near- drowning,
near-hanging, brain and nerve disorders, cardiovascular disorders; and some
digestive system disorders.
It is important to realize that, in most cases, HBOT is best used when combined
with other treatments such as physical therapy and or surgery.
In the USA, the situation stands in marked contrast with many other countries,
where HBOT is used for a much wider range of conditions. Multiple Sclerosis
patients have banded together in Britain to create their own network of
Hyperbaric Chambers. Centers in China treat more than 100,000 patients each year
for a multitude of medical conditions.
Oxygen, The new Growth Factor?
In recent years, our understanding of the intercellular communication of healing
has increased considerably. Cells within a wound receive a myriad of signals
from their environment, the sum of which governs the activity of a cell. The
term "cytokine" is applied to those substances which function as cellular
signals. Growth factors are a subclass of cytokines that specifically stimulate
the proliferation of cells. This stimulation may occur through several different
mechanisms. For example, some growth factors have activities that attract
fibroblasts and inflammatory cells, some act as mitogens, stimulating cell
division, and some effect the production and degradation of the extra-cellular
matrix. All of these phenomenons are the result of a cytokine (growth factor)
signaling the cell nucleus to produce proteins, which account for the observed
activities. A clear understanding of growth factor physiology carries the
promise of clinical advances in wound management. Currently one cytokine,
Platelet Derived Growth Factor, is in clinical use for the management of problem
wounds. As our knowledge of these substances expands, other growth factors will
be added to our clinical armamentarium for the management of non-healing wounds.
Non-healing wounds can also be managed by optimizing the metabolic requirements
of healing e.g. protein, trace elements, and oxygen. The most frequent common
denominator in non-healing wounds is inadequate tissue oxygenation, which
impairs healing and host defenses. Correction of such hypoxia by means of
revascularization or hyperbaric oxygen therapy results in healing for most
patients. Conventional wisdom suggests that oxygen is just a metabolite and
therefore healing, in these circumstances, is simply a reflection of having
sufficient oxygen to meet the energy demands of wound repair. However, some
exciting evidence is now emerging to suggest that oxygen serves a dual role as
both a metabolite and a growth factor. The conceptualization of oxygen as a
growth factor has considerable relevance to the field of hyperbaric oxygen
therapy.
The idea of oxygen acting as a cell signal has already been established in the
setting of hypoxia. As an example, gene expression for erythro-protein
production is largely proportional to the pO2 level in the kidney. It has been
proposed that cells in a non-healing wound may respond to hyperbaric therapy
because the supra-physiologic elevation of tissue oxygen serves as a trigger
signaling that enough oxygen is in the environment to proceed with normal
healing. Subsequent daily exposure to the threshold oxygen level reinforces this
signal and results in gene expression of the protein building blocks required
for healing. Teleologically, it makes sense for cells to conserve resources
until the environmental signals are strong enough and consistent enough to
activate the cell nucleus and begin the healing process.
Two separate groups of investigators have published findings that support this
concept of oxygen as a growth factor. Following a single one-hour exposure to
hyperbaric oxygen, Hehenberger, et al. (1997) demonstrated a dose dependent
stimulation of normal in vitro fibroblasts with a peak increase in cell
proliferation at 2.5 ATA O2. The dose-dependent effect of a single 1-hour
exposure to oxygen suggests a pharmacologic effect of oxygen on cells, as
opposed to an increased metabolic availability of oxygen. These findings
suggest, therefore, that a single brief exposure to hyperbaric oxygen on a daily
basis provides a strong initiating signal for the intracellular events that
culminate in cell proliferation, while sustained hyperoxia has the opposite
effect.
In a study of in vitro fibroblast proliferation using tritium labeled thymidine,
Tompach, et al., found that a single dose of HBO (2.4 ATA for 120 minutes)
produced a sustained stimulation of fibroblasts for 72 hours. If a second
exposure to HBO was given on the same day there was no additional increase in
cell proliferation. Similarly, cultured endothelial cells remained stimulated
for 72 hours following a single 15-minute exposure to HBO. Again, these findings
suggest that we must reconsider oxygen as being more than just a metabolite.
This new paradigm of oxygen as a growth factor is consistent with the clinical
observation that a BID dosing of HBO appears to offer no clear benefit over a QD
dosing schedule for the treatment of chronic wounds. As our understanding of
oxygen physiology increases, we will be in a better position to determine the
optimal dosing of oxygen in both its metabolic and stimulatory roles.

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