Oxygen Treatment for Brain Injury



Oxygen Treatment for Brain Injury

Philip B. James, Emeritus Professor of Medicine, University of Dundee UK.

The use of additional oxygen as a specific treatment has yet to be established in the West not least because medical students are not taught the physics and physiology that establishes oxygen in treatment. After qualification the lack of knowledge of the basic principles often triggers hostility and many thousands of supporting publications are arbitrarily dismissed.

The regulatory agencies of many countries, including the U.S. Food and Drug Agency (FDA) have for many decades referred to oxygen as a drug. The reasons are not clear but recent physiological research has certainly confirmed that oxygen is not just a metabolic substrate; changes in its concentration control cardiac output and blood flow. The latest research has shown that oxygen is responsible for regulating over 8000 genes.

The drug label is only invoked by regulatory authorities when pure oxygen is used for patient care, but much higher levels are constantly used in the diving and aerospace industries. An extraordinary allegation made in a 2018 commentary in the Lancet by a US assistant professor1 implies that breathing a higher level of oxygen than in air may be responsible for an excess of patient deaths when a recent article “Saving lives with high flow nasal oxygen.” was published only three years earlier in the New England Journal of Medicine. 2 There are few areas of medicine that are plagued with such misdirected controversy.

Oxygen Transport and Barometric Pressure

The concentration of oxygen at "normal" atmospheric pressure can be elevated by increasing the percentage from 21 to 100%. A statement on the FDA website describes how even higher levels of oxygen can be breathed by increasing pressure using a sealed room, which is usually referred to as a hyper-baric chamber. Although “baric” pressure is not defined by the FDA it refers to the barometric pressure of the air at sea level and is referred to as 1 Atmosphere Absolute or “1 ATA”. However, it is not constant as it varies with the weather: In Scotland for example it ranges from 0.926 to 1.056 which is more than 10%. This is important but save for a few doctors involved in high altitude mountaineering is not in medical consciousness. Despite this in the death zone on Everest a 10% reduction means the difference between life and death. It is usual to administer close to 100% oxygen (95-99.3%) and this is usually called Hyper-Baric Oxygen Treatment or “HBOT”. The FDA reserves the term “hyper-baric” for pressures exceeding 1.4 times average sea level pressure based on an arbitrary decision accepted by insurers.

“HBOT involves breathing oxygen in a pressurized chamber in which

the atmospheric pressure is raised up to three times higher than normal

Under these conditions, the lungs can gather up to three times more

oxygen than would be possible breathing oxygen at normal air pressure.”



FDA Device Clearance for Pressure Chambers

The FDA is required to clear medical devices for two reasons:

1. To ensure they are safe to use and

2. that use of a device does not result in a more effective treatment being withheld.

The safety of providing oxygen in pressure chambers is determined by well-established engineering principles which, as they also involve aircraft, are rarely challenged. This also applies to the physical laws used in the delivery of oxygen.

The FDA website explains the principles underpinning the effectiveness of oxygen in healing and also the use of additional pressure to achieve adequate oxygen concentrations in injured tissues:

“When tissue is injured, it may require more oxygen to heal. Hyperbaric

oxygen therapy increases the amount of oxygen dissolved in your

blood ..... An increase in blood oxygen may improve oxygen delivery

for vital tissue function to help fight infection or minimize injury.”



FDA and Oxygen Treatment

The above statement is a ringing endorsement of the principles involved in using more oxygen as a treatment. The FDA claim that oxygen is a drug clearly discounts that it is the critical substrate of metabolism and overlooks that oxygen in the air underpins all healing, whether is aided by drugs or needed after surgery. Nevertheless, together with most of the medical profession and in the USA the default gate keepers for insurers, the Undersea and Hyperbaric Medical Society (UHMS), the efficacy of additional oxygen must be demonstrated in every condition using controlled trials as if it is a new drug. This is despite the fact that oxygen concentrations can be actually measured in tissues whereas this is not possible with any drug. The object of giving patients more oxygen to breathe is to raise the tissue concentration to levels known to be necessary for healing to take place.

The Hyperbaric Oxygen Committee of the UHMS is drawn from the membership of the society and their decisions on conditions that can be treated with oxygen are accepted by U.S. insurers. However, the cost of reimbursement for most of these conditions is extremely small viewed against the massive healthcare budget. Few doctors refer their patients for oxygen treatment.

Several of the conditions already accepted for HBOT involve brain damage as, for example, carbon monoxide poisoning and decompression sickness. Concussion is not yet approved but two conditions already reimbursed by insurers, although not specific to the brain, are highly relevant to concussion.

1. Crush injury and compartment syndromes and

2. Arterial insufficiences with enhancement of healing in problem wounds.

Applying these “approved” conditions from the UHMS list to the brain is likely to be contested; for example, it will probably be stated that “crush injuries and compartment syndromes” refer to limbs, not a crush injury of the brain in the compartment formed by the skull. However, the mechanisms involved in both situations are exactly the same: tissue injury with reduced blood flow and oxygen delivery.

Equally major arteries are not involved in concussion but, nevertheless, reduced blood flow and oxygen delivery from brain swelling causes the brain damage. Following the recent autopsy studies of American football players, few would now deny that the long-term effects of concussion are a problem wound of the brain.

Oxygen is only used in mainstream medicine as a nutritional supplement with the so-called “saturation” of haemoglobin with oxygen assuming the status of a clinical constant. But, clearly, blood levels can be perfectly normal when the brain is dying from lack of oxygen, as, for example, in a stroke.

It is not possible for cells to distinguish if the route taken by an oxygen molecule is via the air, or from an oxygen cylinder, and precisely the same physics applies to the normal transfer of dissolved oxygen in maintaining health and treating disease. In fact, it is the only mechanism used for the delivery of oxygen to cells: The red cells that contain haemoglobin are retained in blood. Although the FDA recognises the importance of the dissolved oxygen in supplying the cells of tissues and the need for oxygen in healing, the principles are not taught in medical schools.

The FDA and Evidence for Oxygen Treatment

Unfortunately, not least because of the use of the grammatically incorrect term “hyperbaric oxygen” - it should be “hyperbaric oxygenation” - many still view the oxygen used as somehow different. The FDA compounds this problem by implying that oxygen is a new pharmaceutical application for each condition and practitioners in the hyperbaric field have done little to correct this basic error. Evidence-based medicine was developed to assess drugs of unknown efficacy: It has never been suggested that replacement interventions, such as blood transfusions for haemorrhage, or insulin in diabetic coma, should be subjected to controlled studies. Trials using hyper-baric oxygen treatment to correct a tissue deficiency do not test the need for oxygen they test the efficiency of the medical device used for its delivery to correcting a tissue oxygen deficiency. No placebo effect can restore a deficiency of oxygen, and more is known about the physiology and medicine of oxygen than any other agent. Ironically, no drug can function without it being present.

It is obvious that many conditions resolve without treatment, but only because the oxygen concentration from the air has been sufficient: this oxygen is still needed. As the severity of a disease or injury increases, an incremental increase in the dose used for oxygen treatment is mandated. When 100% oxygen at normal atmospheric pressure is not adequate then a pressure chamber is needed.

NOTE: The FDA site surprisingly states that the “safety and effectiveness” of HBOT as not established in brain injury when, in fact, it already accepts four conditions which involve injury to the brain and listed by the UHMS for reimbursement.

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