What Does the Science Say About Hyperbaric Oxygen Therapy for Long COVID?

In the quest for treatments for people struggling with long COVID, some researchers have evaluated hyperbaric oxygen therapy (HBOT), but the science is far from settled, and questions remain about its feasibility.

Some small studies have shown a possible benefit for select patients suffering from fatigue related to long COVID. But HBOT -- which is more commonly used for wound care or decompression sickness -- might not be a suitable option for most patients, said Monica Verduzco-Gutierrez, MD, of the Long School of Medicine at UT Health San Antonio in Texas.

"Once we know a little bit more about the mechanism of what's happening [with long COVID], then we can really get targeted therapies," Verduzco-Gutierrez told MedPage Today. "Is it endothelial dysfunction and hyperperfusion to the brain? Yes, that's probably one mechanism, and that's where maybe something like hyperbaric [oxygen therapy] could help in that case. Is it immune system dysfunction? ... In that case, hyperbaric treatment wouldn't be something that was helpful."

The research to date on HBOT for long COVID is very limited, but it suggests that the treatment can improve fatigue and cognitive outcomes.

In one randomized, sham-controlled, double-blind trial of HBOT published in Scientific Reports this summer, Shai Efrati, MD, of Tel-Aviv University in Israel, and colleagues showed that there was a significant group-by-time interaction in global cognitive function, attention, and executive function with HBOT in patients with long COVID symptoms for at least 3 months after confirmed SARS-CoV-2 infection. They also found that patients in the treatment group had significant improvements in sleeping scores and psychological symptoms.

"Results indicate that HBOT can induce neuroplasticity and improve cognitive, psychiatric, fatigue, sleep and pain symptoms of patients suffering from post-COVID-19 condition," Efrati and team wrote.

Another study, published last year in Clinical Medicine, showed that 10 long COVID patients who underwent 10 sessions of HBOT over a 12-day period experienced statistically significant improvements in fatigue, global cognition, and executive function.

Tim Robbins, PhD, of the University of Warwick in Coventry, England, and colleagues noted that the results were promising, but the analysis was only an initial evaluation of the treatment. However, "the effect size measures calculated are large, suggesting a substantial improvement and, thus, there is a small likelihood these results are due to chance despite the small initial sample size."

Even so, the reality is that HBOT is suitable for only a small number of patients, said Verduzco-Gutierrez. She pointed out that even if a patient was interested in trying this option, it is off-label and therefore would have a high out-of-pocket cost.

"Right now, [HBOT] for the most part is approved for wound care reasons or for the bends, and otherwise it's not something that is accessible to someone. It could be $10,000 to $12,000 out-of-pocket," she explained.

She suggested that the best approach for patients would be to find an ongoing trial using HBOT for long COVID to alleviate the cost burden, but even then the opportunities are limited.

Still, Verduzco-Gutierrez said there is always utility in casting a wide net, especially when it comes to looking for solutions for patients with long COVID.

"If someone's willing to put financial resources into studying this, then I think we can learn something from it," she noted. "On a global level, could it help a lot of patients? Probably not, in its current state."

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