St. Patrick's Hospital Medical Center
Lopez Jaena St. Batangas City

For inquiries

Telephone: (+63-43) 723-7089 - 92 local 1911

Fax #: (+63-43) 723-8388




Mission Statement

Health care information

How Hyperbaric oxygen therapy works

Indications for Hyperbaric Therapy

Treatment Protocol

Diving Medicine

Education Programs

Insurance Provider Network

Hyperbarichealth Australia




Send us a Feedback here!


How Hyperbaric Oxygenation Therapy Works

Oxygen stands as the key substrate for metabolism. Every day an average adult consumes three pounds of food, three pounds of water and almost six pounds of oxygen. From that six pounds of oxygen about 2 pounds gets into the blood for transport to tissue cells.  Humans need this oxygen in order to complete the energy cycle that sustains life.

Oxygen given with increased pressure can correct many serious health problems.  To provide this increased pressure one must be completely inside a pressurized room, a hyperbaric chamber.  Oxygen breathed while inside a hyperbaric chamber is no different from natural oxygen.  It is natural oxygen, only delivered in a pressurized chamber.  The increased pressure does not change the molecular composition of oxygen.  Increased pressure allows oxygen to get into tissues better.

Extra Pressure Helps Us Absorb More Oxygen

Hemoglobin, the metalloprotein in red blood cells that holds oxygen, can carry only a limited amount of oxygen.  We cannot rely on red blood cells to deliver oxygen to all our tissues in every crisis.  One gram of hemoglobin can only carry 1.34 milliliters of oxygen. Red blood cells can only deliver a limited level of oxygen to tissue cells.  Scientists measure this level, called oxygen tension (or oxygen partial pressure, "pO2")  in units of pressure labeled "mmHg" (the amount of pressure able to raise the equivalent weight of a liquid mercury column, a pretty heavy liquid metal, also used to measure air pressure). Healthy blood circulation provides a tissue pO2 of 39 mmHg or less.  Injuries, infections and diseases can drop this vital tissue oxygen level down to almost zero! As we age we can loose vital lung capacity and the ability to effectively obtain adequate oxygen. Some disease conditions impair oxygen utilization. Also, injuries or conditions with swelling can cause pressure that cuts off circulation flow. This loss of blood flow, called ischemia, cuts off oxygen circulation to the affected areas of the body. This problem drops the pO2 gravely low, destroys tissue, and slows healing. The body response to tissue damage mobilizes scavanger cells called histocytes that crawl with ameboid movement.  This movement requires good oxygen availability.  If oxygen levels drop, the histocyte movement stops and they become part of the problem instead of the solution.  By using increased atmospheric pressure we can dissolve more oxygen into the circulation fluid. This extra oxygen helps revive numb histocytes and gets them back into action.  Research has shown optimal tissue healing occurs when pO2 rises to between 50 and 80 mmHg.  This level assures excellent delivery of oxygen to all the cells that need it.  Oxygen given in a normal room cannot raise tissue oxygen levels to that level because red blood cells cannot carry the extra oxygen. We must raise the atmospheric pressure.  This requires getting inside a pressurized chamber designed for human occupancy.

Limited Time and Pressure Required for Optimal Results

How does being inside a pressurized chamber for a limited time period of 60 minutes help humans heal? When people are inside a chamber pressurized with 50% more air pressure they breathe 50% more air molecules. Breathing nearly pure oxygen in such a chamber gives about 5 times more oxygen than we normally breathe. In one hour we can inhale 1½ pounds of oxygen. Red blood cells instantly fill with oxygen and the extra oxygen dissolves directly into the blood fluid. This extra oxygen helps tissues that may have been deficient in oxygen regain their proper oxgyen levels. This action stimulates healing both during and after the session.  During the session oxygen actives the reticuloendothelial system. After the session our normal homeostatis adapatation promotes healthy function. In order to raise tissue oxygen tension above 50mmHg for this optimal healing one must have nearly pure oxygen delivered under increased atmospheric conditions. Look at the chart below, which closely represents the final tissue oxygen tension, and observe the venous oxygen tension rise when breathing oxygen beginning at 1.5 atmospheres of increased pressure.  A linear increase in tissue oxygen levels occur between 1 and 2 atmospheres absolute (ata). Notice the geometric rise once atmospheric pressure increases beyond 100% more than normal (2 ata).  At this level increased tissue oxygen enters the hyperoxia range and requires expert supervision as nerve sensitivity to extreme oxygen can bring on temporary side-effects.  This sensitivity does not occur at lower pressures.  Some evidence shows that physicians considering treating indicated conditions complicated nerve disorders might want to consider using lower pressures. With the use of increased pressure oxygen therapy, commonly called "hyperbaric oxygenation" (HBO2), for treatment of disease conditions it would be good to know how it affects different tissues.  When we breathe oxygen it runs through the whole body to all tissues. What one tissue needs for optimal function may not equal what another tissue needs. Temporal and physical factors produce different outcomes in different patients.  Let's remember that unless a physician has the patient in a mechanical respirator for respiratory arrest, the independent patient only breathes as they will, some more, some less. The physician really does not control the amount of oxygen that flows into and out of their patients.  Also, the levels of oxidative enzymes in the patient's tissues is seldom measured as a comparison to outcomes.

Many years ago hyperbaric providers used decompression sickness treatment as a standard to measure tissue requirements.  Wound care developed more precise methods to measure tissue oxygen requirements. Those treatments use fairly high pressures and durations. Research more recently uncovered some mechanisms of brain injury and repair.  Life requires oxygen for safe energy conversion in all tissue cells. Any drop of oxygen below 2mmHg to individual cells leads to a process that can shut down cell function.  That anerobic process produces bad chemicals that scientists can extract and measure to determine the state of brain tissue metabolism. Measurement of these chemical markers, as well as some clinical observation, has changed the way we look at how oxygen affects brain injury.  A landmark study examined cerebral metabolism of patients given increased pressure oxygen comparing 1½ to 2.0 ata pressure.  Drs. Holback, Caroli and Wassmann in Bonn, Germany concluded that "At an inspiratory oxygen pressure of 1½ ata we had nearly balanced cerebral glucose metabolism" which they referred to as a "Pasteur effect".   At this level the brain functions in an optimal metabolic state. Increasing the atmospheric pressure to 2.0 ata "increased cerebral glycolysis considerably" indicating a decline in healthy brain function.  The published article also analyzed 59 prior references involving brain and nerve metabolism from as far back as 1879.   Ref: Journal of Neurology 217,17-30 (1977).

Anyone looking to promote the best brain chemistry ought to respect that research study whenever a patient presents with an injury complicated by a brain injury. Hyperbaric physicians usually come from the diving industry and have used much higher pressures to treat injuries.  Asking them to consider this relative lower pressure requires a shift of thinking.  This internet page may help that effort.  Doctors have always had to juggle the varied tissue needs of patients, this is just one more balancing action to consider.

"Very high dosage, over 2 atmospheres absolute [ata] (14.7 psig, 2024 hPa, 33 fsw) can cause [oxidative enzyme disruption] to the brain. These effects are not encountered in clinical practice at the lower pressures [1½ ata] used in treating patients with brain injury. It is not necessary to use air breaks at those lower pressures." - Philip James MB, ChB, DIH, PhD, FFOM.Depending on the tissue type and degree of oxygen deficiency less pressure may be prescribed.  So more pressure is not always better.


The chart shows the increase of oxygen in the venous at different pressures.  To distinguish the linear increase from the geometric increase I have labeled one "increased pressure" and the other "hyperbaric pressure".  What can pressure do? Here's an example, the pressure on a 30" hyperbaric chamber hatch with twice the normal atmospheric pressure has 5 tons of pressure exerted against it!  This type pressure cannot be given in a plastic bag, it requires a solid chamber certified to safely hold the increased pressure.

What is the difference between saturation and oxygen tension?  The problem in advocating proper useage of oxygen involves confusion between saturation and oxygen tension, 100% vrs. 100 mmHg. Only dissolved oxygen contributes to the tension (or partial pressure). The difference in amounts of oxygen transported by plasma (liquid) vrs. hemoglobin. One gram of hemoglobin can only combine with 1.34 ml oxygen to form oxyhemoglobin. In 100ml of healthy blood there is 19ml oxygen as oxyhemoglobin and 0.3ml oxygen in liquid solution.  Thus normally the hemoglobin is near maximum saturation (98%) and the pressure or tension of oxygen in the liquid solution is initially 95mmHg and downline tissue levels drop to 39mmHg or less. Breathing pure oxygen at 2.5 times atmospheric pressure increases the amount of oxygen in (plasma) liquid solution to about 6 ml per 100ml blood.  This increased oxygen volume measureably increases the oxygen tension and downline tissue levels can rise upwards of 200mmHg.

What conditions are treated with hyperbaric oxygenation therapy?  Hyperbaric oxygenation helps the body heal from conditions that have low oxygen  in the tissues causing or complicating the outcome. Repetitive hyperbaric sessions can help many different conditions such as anemia, burns and crush injuries. Compromised skin grafts often improve with hyperbaric oxygenation. Difficult to heal infections treated with hyperbaric oxygenation has attracted interest lately as antibiotic therapy can fail to clear today's resistant strains of pathogens. Treatable infections include such diverse situations as actinomycosis, osteomyelitis, diabetic wounds, gangrene and other deadly soft tissue infections.

How far back does the history of hyperbaric therapy go?  The first pressurized room used to treat health problems was built by an Englishman named Henshaw in 1662; however, it was not until over a century later in 1788, that compressed hyperbaric air was put to large scale use in a diving bell for underwater industrial repairs of an English bridge. The first deep sea diving suit, invented in 1819 by August Siebe, used compressed air supplied to the helmet for generous underwater movement.  A French iron shop in 1834 built the first hyperbaric tank under the direction of Dr. Junod. A copper sphere five feet in diameter with the appropriate viewports and compressed air fittings became the center of attraction for many patients. He reported wonderful recovery from a variety of debilitating conditions in the Bulletin of the Academe of Medicine.  Hyperbaric enthusiasm spread among the European countries during the next forty years. Sick people came from America to try the new therapy. An enterprising Canadian built the first North American hyperbaric chamber in 1860. Early French hyperbaric assisted surgery demonstrated that patients recovered with fewer complications. This interested the European medical profession.   Dr. John S. Haldane studied the effects of compressed oxygen and taught at the University of Dundee in the early 1900's. He developed the first diving tables for the Royal Navy. His legacy gives him the title "Father of Oxygen Therapy" and physicians continue in his line of work to this day.   In 1918 Dr. Orval Cunningham considered the differences between people living or dying through the flu epidemic in the Rocky Mountains. He noticed people in the valley fared better than people in the mountains. He reasoned that denser air in the valley helped people fight the infection. He had an 8' diameter by 30' long hyperbaric chamber built next to his medical clinic. Good outcomes with patients suffering from pneumonia encouraged him to build other chambers. He built the world's largest functional hyperbaric chamber, a 64' steel sphere "hyperbaric hospital" with five floors of living space. The Great Depression in the 1930's ended his project and the steel was scrapped for the war effort in the 1940's.  Harvard Medical School had a hyperbaric chamber built in 1928. It provided a university based medical research program. In the last four decades great strides in HBO2 research has raised the value of this unique therapy. University studies have expanded the list of conditions usefully treated with compressed oxygen. Doctors used to ask, "Can it work?" Now they ask, "How much is needed to completely work?"

Does hyperbaric oxygenation help in pain management?  Related to crush injuries it is apparent that much pain is a result of swelling around sensitive nerves.  Hyperbaric oxygenation acts internally to reduce swelling. For example, a patient with a burned leg from her knee down to her toes had blisters that covered her leg (second degree burns) and the pain was excruciating. After 30 minutes into her first hyperbaric session at 2.5 atmospheres she reported her pain stopped. She completed 15 hyperbaric sessions and within 4 weeks she healed with no scar formation.   Many serious health problems have various forms of ischemia. When ischemia is severe and persistent it may lead to an anaerobic form of tissue metabolism that may perpetuate the entire ischemic process. Ref: W. Boyd A Textbook of Pathology 8th edition pg. 69.   Hyperbaric oxygenation may provide relief.  Ref: A.Sirsjö et al "Hyperbaric oxygen treatment enhances the recovery of blood flow and functional capillary density in post-ischemic striated muscle" 1993 Circulatory Shock 40:9-13.  These research findings indicate that hyperbaric oxygenation may someday find a place in treatment of more pain syndromes. However, to use this therapy many more chambers must become available in doctors offices.

Do people feel different inside a hyperbaric chamber?  Chamber atmosphere pressurization occurs slowly to allow adjustment of ear pressure. As the pressure increases the occupants just yawn, swallow or "blow their nose" to clear pressure changes in their ears. Other than this ear pressure there are no unusual or different sensations.  A hyperbaric oxygenation session allows us time to relax unless one has anxiety about being inside a chamber.  Most of those people find that once they start breathing pure oxygen their anxiety clears and they enjoy the session.  The hour invested inside a chamber provides a place of safety for healing to occur.  


© Batangas Hyperbaric Medicine & Wound Healing Center 2002. All rights reserved.