Effect of hyperbaric oxygen therapy combined with repetitive transcranial magnetic stimulation on vascular cognitive impairment: a randomised controlled trial protocol.

INTRODUCTION: Vascular cognitive impairment (VCI) has an increasing prevalence worldwide, accounting for at least 20%-40% of all diagnoses of dementia. The decline in cognitive function seriously impairs patients' activities of daily living and social participation and reduces their quality of life. However, there is still a lack of advanced, definitive rehabilitation programmes for VCI. Hyperbaric oxygen therapy (HBOT) and repetitive transcranial magnetic stimulation (rTMS) are recognised treatments for improving cognitive impairment. The former can restore oxygen supply in the brain by increasing oxygen partial pressure in brain tissue, while the latter can enhance neuronal excitability and promote synaptic plasticity. However, no studies have explored the effect of HBO combined with rTMS on VCI. METHODS AND ANALYSIS: This study is designed as a single-centre, assessor-blind, randomised controlled clinical trial with four parallel arms. A total of 72 participants will be recruited and randomly assigned to the control group, HBOT group, rTMS group and HBOT combined with rTMS group at a ratio of 1:1:1:1. All enrolled participants will receive conventional treatment. The entire intervention period is 4 weeks, with a 3-week follow-up. Outcomes will be measured at baseline (T0), after a 4-week intervention (T1) and after an additional 3-week follow-up period (T2). The primary endpoint is the Montreal Cognitive Assessment score. The secondary endpoints are Mini-Mental State Examination score, Modified Barthel Index score, latency and amplitude of P300, cerebral cortical oxygenated haemoglobin (HbO2) and deoxygenated haemoglobin (HbR) concentrations as measured by task-state functional near-infrared spectroscopy. ETHICS AND DISSEMINATION: Ethics approval was obtained from the West China Hospital Clinical Trials and Biomedical Ethics Committee of Sichuan University (ethics reference: 2022 (1972)). The findings will be published in peer-reviewed journals and disseminated through scientific conferences and seminars. TRIAL REGISTRATION NUMBER: ChiCTR2300068242.

An overview of hyperbaric oxygen preconditioning against ischemic stroke.

Ischemic stroke (IS) has become the second leading cause of morbidity and mortality worldwide, and the prevention of IS should be given high priority. Recent studies have indicated that hyperbaric oxygen preconditioning (HBO-PC) may be a protective nonpharmacological method, but its underlying mechanisms remain poorly defined. This study comprehensively reviewed the pathophysiology of IS and revealed the underlying mechanism of HBO-PC in protection against IS. The preventive effects of HBO-PC against IS may include inducing antioxidant, anti-inflammation, and anti-apoptosis capacity; activating autophagy and immune responses; upregulating heat shock proteins, hypoxia-inducible factor-1, and erythropoietin; and exerting protective effects upon the blood-brain barrier. In addition, HBO-PC may be considered a safe and effective method to prevent IS in combination with stem cell therapy. Although the benefits of HBO-PC on IS have been widely observed in recent research, the implementation of this technique is still controversial due to regimen differences. Transferring the results to clinical application needs to be taken carefully, and screening for the optimal regimen would be a daunting task. In addition, whether we should prescribe an individualized preconditioning regimen to each stroke patient needs further exploration.

Efficacy and safety of hyperbaric oxygen therapy for fibromyalgia: a systematic review and meta-analysis.

OBJECTIVE: To investigate the efficacy and safety of hyperbaric oxygen therapy (HBOT) for fibromyalgia (FM). DESIGN: A systematic review and meta-analysis. DATA SOURCES: PubMed, EMBASE, Cochrane Library, Web of Science, VIP (China Science and Technology Journal Database), CNKI (China National Knowledge Infrastructure) and WanFang database were searched from from inception to 22 October 2022. ELIGIBILITY CRITERIA: We included clinical trials (randomised controlled and non-randomised controlled trials) of HBOT for FM. DATA EXTRACTION AND SYNTHESIS: Two researchers independently screened the literature, extracted data and evaluated the quality of the included studies, with disagreements resolved by a third researcher. The Cochrane Collaboration checklists and the Methodological Index for Non-randomised Studies were used to assess the risk of bias. Meta-analysis was performed by RevMan V.5.4.1 software. Random effect models were used for meta-analysis. RESULTS: Nine studies were included in this review, with a total of 288 patients. For pain assessment, we combined the results of the Visual Analogue Scale and Widespread Pain Index. The results showed that HBOT could relieve the pain of FM patients compared with the control intervention (standardised mean difference=-1.56, 95% CI (-2.18 to -0.93), p<0.001, I 2=51%). Most included studies reported that HBOT ameliorated tender points, fatigue, multidimensional function, patient global and sleep disturbance in FM. Adverse events occurred in 44 of 185 patients (23.8%). Twelve patients (6.5%) withdrew because of adverse reactions. No serious adverse events or complications were observed. CONCLUSIONS: HBOT might have a positive effect in improving pain, tender points, fatigue, multidimensional function, patient global and sleep disturbance in FM, with reversible side effects. Low pressure (less than 2.0 atmospheric absolute) may be beneficial to reduce adverse events in FM. Further studies should be carried out to evaluate the optimal protocol of HBOT in FM. PROSPERO REGISTRATION NUMBER: CRD42021282920.

Addition of hyperbaric oxygen therapy versus usual care alone for inflammatory bowel disease: A systematic review and meta-analysis.

Objective: Inflammatory bowel disease (IBD) is a chronic idiopathic inflammatory disease that includes ulcerative colitis (UC) and Crohn's disease (CD). Hyperbaric oxygen therapy (HBOT) involves breathing pure oxygen in a pressurized environment. Existing literature suggests that HBOT may be an effective therapy for IBD, but a quantitative analysis is lacking. This study aims to estimate the adjunctive role of HBOT in treating IBD and lowering its recurrence rate. Design: Systematic review and meta-analysis. Methods: The Cochrane Library, EMBASE, PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database (VIP), and Wanfang databases were systematically searched by two reviewers independently. Meta-analyses were performed using Review Manager (RevMan, version 5.3). A random-effects model was applied due to the heterogeneity between studies. Results: Twenty-nine out of the initially identified 606 articles were covered in this review, with a total of 2151 patients (2071 for UC and 80 for CD). No randomized data of HBOT for CD were included. Among UC patients, usual care plus HBOT were more likely to achieve a clinical response than usual care alone (risk ratio [RR], 1.24; 95% confidence interval (CI), 1.17 to 1.31; P < 0.001). Subgroup analysis showed that the number of HBOT sessions had no statistically significant effect on overall efficacy (P > 0.05). The pooled data showed a lower recurrence rate in the usual care plus HBOT group (RR, 0.35; 95% CI, 0.24 to 0.53; P < 0.001). The standardized mean difference in the serum tumor necrosis factor level between HBOT and non-HBOT groups was -2.13 (95% CI, -3.09 to -1.18; P < 0.001). No severe adverse events of HBOT were observed. Conclusions: HBOT might be an effective and safe adjunctive treatment for IBD. Further studies are required to investigate the optimal protocol of HBOT in IBD treatment.