Hyperbaric oxygen therapy (HBT) is a form of treatment where patients breathe pure unadulterated (100%) oxygen at pressures higher than the average atmospheric pressure, typically double or triple the level. HBT is a well-established form of treatment for decompression sickness that usually afflicts scuba and deep sea divers (including military personnel). In recent years, HBT has been used to treat a wide and growing number of health issues, ranging from infected wounds to radiation-related injuries.
Records show that primitive forms of HBT have been used to treat a variety of afflictions from as early as the 18th century following the ‘discovery’ of oxygen in 1775 by Yorkshireman Joseph Priestley. Some of the more notable early use of HBT was in the treatment of pulmonary conditions in the early 19th century in several ‘spas’ across Europe and patients infected with Spanish flu in 1918.
However, modern clinical use of HBT only begun in the mid-1950s when it was used to detect and enhance the radiosensitivity of tumours (1955, Churchill-Davidson) and assist in a surgical procedure (1956, University of Amsterdam).
In the 60s and 70s, enthusiasm for HBT grew even larger, and as the understanding of gas exchange physiology grew, its use was expanded to treat carbon monoxide poisoning, emphysema and many other diseases.
Since the 70s, the majority of HBT practitioners have become members of the Kensington-based Underseas and Hyperbaric Medical Society (UHMS) and follows the organisation’s self-regulatory model. Today, UHMS is considered the most reputable HBT organisation in the world and its periodical guidelines is widely accepted as the industry standard for all matters relating to HBT.
A hyperbaric oxygen therapy chamber at the Moose Jaw Union Hospital in Saskatchewan, Canada. Image courtesy of Wikimedia Commons.
The literal translation of hyperbaric is greater than normal (hyper) pressure (baric). Oxygen, meanwhile, is a colourless and odourless gas that stimulates cell growth and repairs. If we put all the words together, HBT becomes self-explanatory – it facilitates and accelerates the growth and repair of cells in the human body using an incredible amount of pure oxygen.
During the therapy, patients breathe in unadulterated oxygen either through a mask, or from air inside a sealed chamber, which is pressured up to three times the normal atmospheric level. This huge rush of oxygen to the body will cause the gas to be dissolved into blood plasma cells which will then be circulated around the body. At specific locations in the body, the flood of oxygen will accelerate the growth and recovery of the body’s cells and tissues.
HBT’s benefits can be broadly divided into three categories: all clinical settings, selected clinical settings, and non-clinical settings. There are still a few questions surrounding the second category, but the third category remains highly contentious as there is very little body of evidence to support HBT’s effectiveness against the numerous listed medical conditions – and there are fears of the potential of clinical creep and misrepresentation in a non-clinical environment.
• Decompression illness
• Carbon monoxide and cyanide poisoning
• Gas and air embolism
• Chronic non-healing wounds (diabetes-related)
• Localised hypoxia and stimulation of angiogenesis (oxygen-related deficiencies)
• Clostridial myonecrosis (gas gangrene)
• Ischemia (insufficient supply of blood to organs)
• Necrotizing infections
• Certain types of osteomyelitis
• Radiation-related tissue damage (typically chemotherapy) and radiation proctitis
• Compromised surgical grafts and skin flaps
• Clostridial myonecrosis
• Compartment syndrome
• Exceptional blood loss
• Cerebral palsy
• Cluster headaches and migraine
• Stroke and vascular disease
• Widespread fungal infection
• Multiple sclerosis
• Parkinson’s disease
• Trigeminal neuralgia
• Lyme’s disease
• Chronic fatigue
• Crohn's disease
• Muscle recovery (for athletes)
• Decreased immune function
• Poisonous bites
Under trained supervision, HBT is considered a relative safe procedure. However, the therapy does have some inherent risks, even if complications rarely occur.
• Temporary myopia (the pressurised environment contracts the lens in the eyes, which can, amusingly, improve far sightedness)
• Accelerated maturing/worsening of cataracts
• Ear injuries (caused by extreme change in pressure)
• Oxygen toxicity (which could lead to seizures, facial twitching, nausea, ringing in the ears, etc.)
• Barotrauma (pneumothorax/lung collapse and discomfort in ears, sinuses or teeth cavities)
• Decompression illness