Nephroprotective effects of hyperbaric oxygen therapy in murine models of acute kidney injury: A systematic review and meta-analysis.

Aims: Acute kidney injury (AKI) is a life-threatening condition marked by sudden kidney function loss and azotemia. While its management is limited to supportive care, the effects of hyperbaric oxygen therapy (HBO) on AKI remain a subject of conflicting animal research. This study aimed to systematically review and meta-analyze HBO's effects on renal function biomarkers serum creatinine (SCr) and blood urea nitrogen (BUN) in murine AKI models, also exploring tissue-level nephroprotection.

Main Methods: The PUBMED, SciELO, and LILACS databases were searched until September 5, 2024. Effect sizes of HBO on SCr and BUN levels were expressed as standardized mean difference (SMD) alongside 95 % confidence interval (CI), calculated by random-effects model. Extracted data also included murine specie/strain, HBO parameters, AKI induction method (toxic, ischemic, others), and histological findings. Study quality and publication bias were respectively assessed using the CAMARADES checklist and Egger's test. This review adhered to PRISMA guidelines and was registered in PROSPERO (CRD42022369804).

Key Findings: Data synthesis from 21 studies demonstrates that HBO effectively reduces azotemia in AKI-affected animals (SCr's SMD = -1.69, 95 % CI = -2.38 to -0.99, P < 0.001; BUN's SMD = -1.51, 95 % CI = -2.32 to -0.71, P < 0.001) while mitigating histological damage. Subgroup analyses indicate that HBO particularly benefits ischemic and other AKI types (P < 0.05). In contrast, data from toxic AKI models were inconclusive due to insufficient statistical power (P > 0.05, 1-β < 30 %).

Significance: This meta-analysis provides compelling evidence supporting the adjunctive use of HBO in AKI management.