Hyperbaric Oxygen Therapy may Improve Pain, Fatigue in Patients with Fibromyalgia

Hyperbaric oxygen therapy (HBOT) may have positive effects on pain, fatigue, multidimensional function, sleep disturbance, tender points, and patient global in patients with fibromyalgia (FM), according to a study published in BMJ Open.¹ Low pressure (less than 2.0 atmospheric absolute) may be able to reduce adverse events. However, future studies are needed to determine optimal protocols.

“Accumulating evidence suggests that HBOT is a non-invasive modality with lasting efficacy to treat FM,” lead investigator Xinxin Chen, an investigator associated with Sichuan University, and colleagues, stated. “HBOT is conducted by intermittently breathing 100% oxygen in a pressure chamber above one atmospheric absolute pressure (ATA). HBOT can raise the partial pressure of oxygen in alveoli, leading to a favorable increase in dissolved oxygen in plasma.”

PubMed, EMBASE, Web of Science, Cochrane Library, Wan Fang, China National Knowledge Infrastructure (CNKI), and the China Science and Technology Journal Database (VIP) were used in the systematic review and meta-analysis to determine the safety and efficacy of HBOT for the treatment of FM.

Databases were searched from inception through October 2022 to identify relevant clinical trials, both randomized controlled (RCT) and non-randomized controlled (non-RCT). Once recognized, 2 researchers screened the data and evaluated the study quality. The risk of bias was determined via the Cochrane Collaboration checklists and the Methodological Index for Non-randomized Studies, while meta-analysis was conducted by RevMan V.5.4.1 software.

The primary outcome measure was pain, while secondary outcomes included patient global, sleep disturbances, fatigue, tenderness, multidimensional function, and any adverse events.

Ultimately, 9 studies (3 RCTs and 6 non-RCTs), comprised of 288 patients, were included in the review. Pain assessment was evaluated using results from the Visual Analogue Scale (VAS) and Widespread Pain Index (WPI). HBOT was able to better alleviate pain in this patient population when compared with the control intervention (standardized mean difference [SD] = −1.56, 95% confidence interval [CI] (−2.18 to –0.93), P <0.001, I² = 51%).

The majority of included studies observed improvements in fatigue, patient global, sleep disturbance, multidimensional function, and tender points. One study assessing patient global reported that at 3-month follow-up, patients stated that their fibromyalgia symptoms were “a great deal better,” indicating that the effects of HBOT may be long-term.

Although no serious adverse events were reported, adverse events occurred in 23.8% (n = 44/185) patients, which led to 6.5% (n = 12) patients withdrawing from the study. The most common adverse events were mild barotrauma, new-onset myopia, headache, dizziness, claustrophobia, and an inability to adjust ear pressure.

The study was limited by the small number of RCTs included, which may have led to an overall risk of bias or insufficient evidence. Further, the HBOT protocols between studies had clinical heterogeneity, which may have skewed results. No subgroup analysis evaluating the efficacy of different regimens could be performed due to these factors. Lastly, only data from Chinese and English databases were included, thus potentially limiting data availability.

“There is growing evidence that HBOT is a non-invasive way to treat chronic pain diseases with long-lasting efficacy and minor adverse effects,” Chen concluded. “In murine models of pain, HBOT has been shown to inhibit pain sensation, which may be due to the nitric oxide-dependent release of opiate peptides and could be restrained by an antagonist, naltrexone.”

References

1. ^{Chen X, You J, Ma H, Zhou M, Huang C. Efficacy and safety of hyperbaric oxygen therapy for fibromyalgia: a systematic review and meta-analysis. BMJ Open. 2023;13(1):e062322. Published 2023 Jan 23. doi:10.1136/bmjopen-2022-062322}