Hyperbaric oxygen therapy (HBOT)

Hyperbaric oxygen therapy (HBOT) is breathing medical oxygen inside a chamber pressurized to 1.5–2.5 atmospheres absolute (ATA). At that pressure oxygen no longer travels only on hemoglobin; it dissolves into the plasma itself, and tissue that normal breathing cannot reach, because its capillaries are damaged or inflamed, receives 10–15 times the usual amount. St. George Hospital runs HBOT on its ward in daily sessions as one element of the programs that also use the detoxification therapies and the infusion and immune therapies.

HBOT has approved indications in standard medicine: problem wounds including diabetic foot ulcers, tissue damaged by radiotherapy, carbon monoxide poisoning and diving injuries. We use it for those where they arise, and, as an individual treatment attempt decided with the patient after medical consultation, in Post-COVID, ME/CFS and chronic Lyme disease, where the question is whether poorly perfused tissue and an inflamed nervous system respond to the same oxygen signal.

HBOT has a list of indications recognized by the Undersea and Hyperbaric Medical Society and reimbursed in standard care. The grade differs sharply by indication.

In diabetic foot ulcers the Cochrane review of twelve randomized trials (577 participants) found that adding HBOT roughly doubled the rate of ulcers healed at six weeks, but the difference was no longer evident at one year and the amputation rate did not differ; the authors judged the trials flawed enough that they were not confident in the result (Kranke et al., Cochrane Database Syst Rev, 2015). In late radiation tissue injury the 2023 Cochrane update of eighteen trials (1,071 participants) found that HBOT may bring complete resolution or significant improvement, with the clearest signals in radiation proctitis, cystitis and osteoradionecrosis of the jaw, and moderate-certainty evidence for less pain in osteoradionecrosis at twelve months (Lin et al., Cochrane Database Syst Rev, 2023). HBOT is established standard care in both settings; the randomized evidence behind it is of low to moderate certainty.

In Post-COVID the evidence is emerging and comes from a randomized, sham-controlled, double-blind trial of 73 patients with symptoms for at least three months. Forty daily sessions improved global cognitive function, attention and executive function, energy, sleep, psychiatric symptoms and pain interference compared with sham, and the clinical changes were accompanied by improved perfusion and microstructural changes on brain MRI (Zilberman-Itskovich et al., Sci Rep, 2022). It is one trial from one center, and the follow-up was one to three weeks after the last session.

In ME/CFS the evidence is limited. The one published study is an open series of sixteen patients diagnosed by the Fukuda criteria who received fifteen sessions over three weeks; fatigue severity and fatigue-related quality of life scores improved and no complications occurred, but there was no control group (Akarsu et al., Undersea Hyperb Med, 2013). For chronic Lyme disease there are no controlled trials of HBOT. What the evidence does not show is a change in long-term outcomes for any post-viral or chronic infectious condition.

Contraindications and side effects

• Untreated pneumothorax is the absolute contraindication: trapped air expands on decompression and can cause a tension pneumothorax.
• Certain chemotherapies: prior bleomycin, and current doxorubicin, cisplatin or disulfiram, which increase the risk of lung or oxygen toxicity. Patients on or after these drugs are assessed individually with the treating oncologist.
• Severe COPD with air trapping, an acute upper respiratory or sinus infection, uncontrolled seizure disorder, high fever and pregnancy are reviewed case by case; some are temporary and the course starts when they have resolved.
• Claustrophobia is manageable in a transparent monoplace chamber; tell us beforehand.

The quantified side-effect review puts middle-ear barotrauma as the most frequent event and a temporary myopic shift as the most frequent after a longer course; oxygen toxicity seizures are rare at the pressures used in wound and radiation protocols, and HBOT lowers blood glucose (Heyboer et al., Adv Wound Care, 2017). The Cochrane radiation review measured the same two events.

If you want to know whether HBOT belongs in your plan, write a short inquiry to the International Office, free of charge; it asks for your findings afterwards. A physician reads them before the video consultation and tells you how many sessions and what else the program would contain. You can also read how a stay runs before you decide.