Hyperbaric oxygen therapy (HBOT) is defined as the use of oxygen at higher than atmospheric pressure for the treatment of underlying disease processes and the diseases they produce. Modern HBOT in which 100% O2 is breathed in a pressurized chamber dates back to the 1930s, when it was first used for treatment of decompression illness in divers. There are currently 13 FDA-approved uses for HBOT, including decompression illness, gas gangrene, air embolism, osteomyelitis, radiation necrosis, and the most recent addition—diabetic ulcers.
Just as practicing physicians routinely identify off-label uses for medications, over the years HBOT physicians have identified many other conditions that respond to HBOT. A number of chronic neurological conditions including traumatic brain injury (TBI) have been shown to respond particularly well. There is published literature supporting HBOT’s efficacy for TBI, including human trials and animal research, but due to the impossibility of arranging sham pressure there are no rigorous double-blind placebo-controlled trials.1 As a result, HBOT is not FDA-approved for TBI, and insurance will generally not pay for it.
HBOT can dramatically and permanently improve symptoms of chronic TBI months or even many years after the original head injury. This assertion is generally met with skepticism within the medical establishment because we have been taught for generations that any post-concussion symptoms persisting more than 6 months or so after a head injury are due to permanent brain damage that cannot be repaired. Therefore, treatment has been limited to symptom management and rehabilitative services, and any claim suggesting that fundamental healing is possible is suspect. The combination of entrenched skepticism and lack of insurance coverage has made it very difficult for patients to access treatment.
Another source of skepticism has been the large number of disparate conditions that are claimed to be helped by HBOT. A brief review of the mechanisms through which HBOT triggers healing responses, with particular reference to the modern understanding of the pathophysiology of TBI, provides a theoretical framework to explain these claims.
Physiological effects of HBOT
About 97% of the total oxygen in blood is tightly bound to hemoglobin when breathing room air (21% O2) at sea level (1 atmosphere, or 1 ATM; 3% of the oxygen is dissolved in blood serum. This amounts to about 0.3 mL of oxygen dissolved in 100 mL of serum. By the time oxygen diffuses out of the circulatory system and ultimately reaches the mitochondria, there is just a trace amount present. HBOT’s primary mechanism is to temporarily hyper-oxygenate body tissues. HBOT delivered at 1.3 ATM increases dissolved oxygen in serum by a factor of 7. HBOT delivered in hard chambers at 2.5 to 3.0 ATM increases dissolved oxygen by a factor of 15 or more. Oxygen levels in body tissues outside the circulatory system will be increased commensurately.
If a hyper-oxygenated state is maintained for long periods it will cause significant oxidative damage, but when it is “pulsed” for an hour it triggers a variety of healing processes without overwhelming the body’s anti-oxidant system. The currently known mechanisms include a powerful anti-inflammatory effect, reduction of edema, increased blood perfusion, angiogenesis, stimulation of the immune system, stimulation of endogenous antioxidant systems, mobilization of stem cells from bone marrow, axonal regrowth, and modulation of the expression of thousands of genes involved in the inflammatory response and various healing responses.2,3
Dr Goderez is a psychopharmacologist and integrative medicine practitioner in private practice. He offers hyperbaric oxygen therapy for traumatic brain injury and other neuropsychiatric conditions including dementia and radiation necrosis.
1. Harch PG, Andrews SR, Fogarty EF, et.al. A phase I study of low-pressure hyperbaric oxygen therapy for blast-induced post-concussion syndrome and post-traumatic stress disorder. J Neurotrauma. 2012;29:168-185.
2. Efrati S, Ben-Jacob E. How and why hyperbaric oxygen therapy can bring new hope for children suffering from cerebral palsy: an editorial perspective. Undersea Hyperbaric Med. 2014;41:71-74.
3. Harch, P. Hyperbaric oxygen in chronic traumatic brain injury: oxygen, pressure, and gene therapy. Med Gas Res. 2015;5:9.
4. Harch P, Mccullough V. The Oxygen Revolution. Hobart, NY: Hatherleigh Press; 2010.
5. Mukherjee A, Raison M, Sahni T, et.al. Intensive rehabilitation combined with HBO2 therapy in children with cerebral palsy: a controlled longitudinal study. Undersea Hyperbaric Med. 2014;41:77-85.
6. Harch PG, Fogarty EF. Hyperbaric oxygen therapy for Alzheimer’s dementia with positron emission tomography imaging: a case report. Med Gas Res. 2018:8:181-184.
7. Jain KK. Textbook of Hyperbaric Medicine. New York, NY: Springer International Publishing AG; 2017: 345-348.