Assessment of the Efficacy and Safety of Hyperbaric Oxygen Therapy on Pain in Patients with Fibromyalgia: A Systematic Review and Meta-analysis of Randomised Controlled Studies

Hyperbaric oxygen therapy (HBOT) is an adjunctive treatment for chronic pain. The current study aimed to perform a systematic evaluation and meta-analysis of randomised controlled trials (RCTs) to assess the clinical efficacy and safety of HBOT for pain reduction in fibromyalgia (FM) patients compared to conventional therapy. A systematic search of medical subject headings and keywords associated with HBOT for FM patients was conducted using electronic databases: MEDLINE/ PubMed, Web of Science, Cochrane Library Central Register of Controlled Trials, and Scopus. Google Scholar was also combed to detect likely non-indexed available studies. We also searched manually through reference lists of identified original articles or reviews for relevant articles. The http://www.clinicaltrial.gov was examined for all research protocols being conducted/ planned. The Cochrane Collaboration tool and Higgins and Thompson’s I2 method determined the risk of bias and heterogeneity. The primary outcome was the effect of HBOT on pain; secondary outcomes included adverse effects of HBOT, assessment of the quality of life, functional impairment, psychological symptoms, and sleep quality. The overall quality of evidence was assessed with the GRADE approach. Cochrane RevMan software (version 5.4) was used for data analysis. Results were synthesised through a general summary of the characteristics and findings of each study. We also analysed different HBOT protocols and their outcomes across the studies. Five RCTs enrolling 91 and 89 patients in FM and control groups were included in the present study. HBOT results in decreased tender points (-6.23 (95 % CI: -7.76, -4.71) P < 0.0001), increased pain threshold (0.57 (95% CI: 0.3, 0.83) P < 0.00001) and a decreased Visual Analog scale (VAS) score for pain (-5.31(95 % CI: -8.17, -2.45)). Quality of life, sleep, functional impairment, etc., also improved after HBOT. HBOT is effective in pain and other associated outcomes in FM patients. In FM patients, high-quality evidence in favour of HBOT to improve pain, fatigue, quality of life, sleep, psychological outcomes, etc., is required.