Effects of hyperbaric oxygen therapy on patients with spinal cord injury: A systematic review and meta-analysis of Randomized Controlled Trials

BACKGROUND: The effects of hyperbaric oxygen therapy (HBO) for spinal cord injury (SCI) are controversial. OBJECTIVE: The purpose of this study was to evaluate the effects of HBO therapy on motor function, sensory function, and psychology after SCI. METHOD: We searched the following databases: Medline, Embase, PubMed, Ovid, Cochrane library, China National Knowledge Infrastructure (CNKI), Wan Fang, and VIP up to May 2020. We included Randomized Controlled Trials (RCTs) which investigated patients with SCI received HBO during hospitalization. Motor function, sensory function, and psychology status were measured by commonly used scales including American Spinal Injury Association (ASIA) motor score, Modified Barthel Index (MBI), ASIA sensory score, Hamilton Depression Scale (HAMD), and Hamilton Anxiety Scale (HAMA). We performed a meta-analysis by calculating mean difference (MD) to determine the effect of HBO on three levels of function on patients with SCI. We evaluated heterogeneity by I-2 test, and I-2 > 50% was significant. RESULTS: A total of 1746 studies were identified initially, and 11 studies were included, involving 875 participants. HBO therapy significantly improved the ASIA motor score (MD 15.84, 95% CI 9.04 to 22.64, I-2 = 87%). Six trails suggested that HBO therapy statistically promoted ASIA sensory score (MD 66.30, 95% CI 53.44 to 79.16, I-2 = 95%). The other four trails suggested that HBO therapy statistically increased the light touch score (MD 9.27, 95% CI 3.89 to 14.65, I-2 = 91%) and needling score (MD 10.01, 95% CI 8.60 to 11.43, I-2 = 95%), respectively. HBO therapy was implicated in the significant improvement of MBI (MD 13.80, 95% CI 10.65 to 16.94, I-2 = 0%). HBO therapy also decreased the HAMA (MD 2.37, 95% CI 2.72 to 2.02, I-2 = 0%) and HAMD (MD 3.74, 95% CI 5.82 to 1.65, I-2 = 90%). CONCLUSIONS: HBO therapy may improve motor function, sensory function and psychology after SCI compared to conventional treatments. More high-quality, large sample size RCTs are needed to support these perspectives.