HYPERBARIC OXYGEN THERAPY

What is hyperbaric oxygen therapy?

Hyperbaric oxygen therapy involves breathing in 100% oxygen under air pressure two to three times higher than normal air pressure. This allows your lungs to take in more oxygen than they can at normal air pressure. Hyperbaric oxygen therapy is typically an outpatient procedure that can be done in an individual unit for one patient within a chamber or a room for multiple people through a mask. This procedure is often used for wound healing or serious infections, as the extra oxygen can release growth factors and stem cells to promote healing and help fight bacteria.¹

How can hyperbaric oxygen therapy help alleviate certain long COVID symptoms?

The mechanisms behind long COVID symptoms are not fully understood. Still, they are believed to be partly due to increased activation of proteins that promote clotting and hyperactive inflammatory and autoimmune responses. Hyperbaric oxygen therapy can improve circulation within our smallest blood vessels, inhibit the release of inflammatory mediators, inhibit autoimmune responses, and promote neurological repair.² Hyperbaric oxygen therapy is proposed to improve the following long COVID symptoms: chronic fatigue; neurocognitive functions such as energy, sleep, pain, and psychiatric symptoms; and cardiac dysfunction such as shortness of breath.

What evidence supports the use of hyperbaric oxygen therapy for long COVID?

Several randomized control trials have studied the use of hyperbaric oxygen therapy for long COVID. The first evaluation of hyperbaric oxygen therapy for long COVID was a study done with ten patients who each received ten sessions over 12 days, each lasting 105 minutes with three 30-minute exposures to 100% oxygen. The study found a significant improvement in fatigue, cognition, information processing, executive function, attention, and verbal function.³ Another trial with 73 patients randomized to receive hyperbaric oxygen therapy daily for 40 sessions also saw significant improvement in energy, sleep, psychiatric symptoms, and pain.⁴

Other long-term effects of COVID include cardiac injury, such as inflammation in the heart and increased risk of arrhythmias, heart disease, heart failure, or stroke. One trial looked at the effect of hyperbaric oxygen therapy on cardiac function in long COVID patients in 60 patients randomized to receive 40 daily hyperbaric oxygen therapy sessions or placebo. The outcome of interest was global longitudinal strain (or GLS), which measures how well the heart is pumping blood to the rest of the body. The study found that GLS was significantly increased after hyperbaric oxygen therapy.⁵

What are some things to watch out for with hyperbaric oxygen therapy?

Hyperbaric oxygen therapy has risks, including middle ear injuries due to the higher air pressure, temporary nearsightedness, lung collapse, seizures (rarely), lowered blood sugar in people treated with insulin for diabetes, and a potential risk of fire.¹ It is important to remove any hair or skin products that are petroleum-based, as they can pose a potential fire hazard.

An ongoing trial released interim safety data on 20 patients randomized to receive hyperbaric oxygen therapy or placebo and found that 60% of the participants experienced at least one adverse event.⁶ The most common adverse events were cough and chest pain or discomfort. All adverse events were temporary. No serious adverse events were reported.

Hyperbaric oxygen therapy cannot be used in patients with a collapsed lung. It should typically not be used in obstructive lung disease or a recent ear or thoracic (chest) surgery.

References:

1)      Mayo Clinic Staff. Hyperbaric oxygen therapy. Mayo Clinic. Nov 4, 2022. Accessed November 5, 2023. https://www.mayoclinic.org/tests-procedures/hyperbaric-oxygen-therapy/about/pac-20394380

2)      Pan JQ, Tian ZM, Xue LB. Hyperbaric Oxygen Treatment for Long COVID: From Molecular Mechanism to Clinical Practice. Curr Med Sci. 2023 Nov 4. doi: 10.1007/s11596-023-2799-1

3)      Robbins T, Gonevski M, Clark C, Baitule S, Sharma K, Magar A, Patel K, Sankar S, Kyrou I, Ali A, Randeva HS. Hyperbaric oxygen therapy for the treatment of long COVID: early evaluation of a highly promising intervention. Clin Med (Lond). 2021 Nov;21(6):e629-e632. doi: 10.7861/clinmed.2021-0462

4)      Zilberman-Itskovich S, Catalogna M, Sasson E, Elman-Shina K, Hadanny A, Lang E, Finci S, Polak N, Fishlev G, Korin C, Shorer R, Parag Y, Sova M, Efrati S. Hyperbaric oxygen therapy improves neurocognitive functions and symptoms of post-COVID condition: randomized controlled trial. Sci Rep. 2022 Jul 12;12(1):11252. doi: 10.1038/s41598-022-15565-0

5)      Leitman M, Fuchs S, Tyomkin V, Hadanny A, Zilberman-Itskovich S, Efrati S. The effect of hyperbaric oxygen therapy on myocardial function in post-COVID-19 syndrome patients: a randomized controlled trial. Sci Rep. 2023 Jun 10;13(1):9473. doi: 10.1038/s41598-023-36570-x

6)      Kjellberg A, Hassler A, Boström E, El Gharbi S, Al-Ezerjawi S, Kowalski J, Rodriguez-Wallberg KA, Bruchfeld J, Ståhlberg M, Nygren-Bonnier M, Runold M, Lindholm P. Hyperbaric oxygen therapy for long COVID (HOT-LoCO), an interim safety report from a randomised controlled trial. BMC Infect Dis. 2023 Jan 20;23(1):33. doi: 10.1186/s12879-023-08002-8

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