Abstract：
BACKGROUND: Cerebral ischemia due to hypoxia is a major cause of secondary brain injury and is associated with higher morbidity and mortality in patients with acute brain injury. Hyperoxia could improve energetic dysfunction in the brain in this setting. Our objectives were to perform a systematic review and meta-analysis of the current literature and to assess the impact of normobaric hyperoxia on brain metabolism by using cerebral microdialysis.
METHODS: We searched Medline and Scopus, following the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement; we searched for retrospective and prospective observational studies, interventional studies, and randomized clinical trials that performed a hyperoxia challenge in patients with acute brain injury who were concomitantly monitored with cerebral microdialysis. This study was registered in PROSPERO (CRD420211295223).
RESULTS: We included a total of 17 studies, with a total of 311 patients. A statistically significant reduction in cerebral lactate values (pooled standardized mean difference [SMD] - 0.38 [- 0.53 to - 0.23]) and lactate to pyruvate ratio values (pooled SMD - 0.20 [- 0.35 to - 0.05]) was observed after hyperoxia. However, glucose levels (pooled SMD - 0.08 [- 0.23 to 0.08]) remained unchanged after hyperoxia.
CONCLUSIONS: Normobaric hyperoxia may improve cerebral metabolic disturbances in patients with acute brain injury. The clinical impact of such effects needs to be further elucidated.
METHODS: We searched Medline and Scopus, following the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement; we searched for retrospective and prospective observational studies, interventional studies, and randomized clinical trials that performed a hyperoxia challenge in patients with acute brain injury who were concomitantly monitored with cerebral microdialysis. This study was registered in PROSPERO (CRD420211295223).
RESULTS: We included a total of 17 studies, with a total of 311 patients. A statistically significant reduction in cerebral lactate values (pooled standardized mean difference [SMD] - 0.38 [- 0.53 to - 0.23]) and lactate to pyruvate ratio values (pooled SMD - 0.20 [- 0.35 to - 0.05]) was observed after hyperoxia. However, glucose levels (pooled SMD - 0.08 [- 0.23 to 0.08]) remained unchanged after hyperoxia.
CONCLUSIONS: Normobaric hyperoxia may improve cerebral metabolic disturbances in patients with acute brain injury. The clinical impact of such effects needs to be further elucidated.
摘要：
背景：缺氧引起的脑缺血是继发性脑损伤的主要原因，并且与急性脑损伤患者的较高发病率和死亡率有关。在这种情况下，高氧可以改善大脑的能量功能障碍。我们的目标是对当前文献进行系统回顾和荟萃分析，并通过使用脑微透析评估常压高氧对脑代谢的影响。
方法：我们搜索了Medline和Scopus，遵循系统评价和荟萃分析声明的首选报告项目的建议；我们搜索了回顾性和前瞻性观察性研究，介入研究,和随机临床试验，对同时监测脑微透析的急性脑损伤患者进行高氧攻击。本研究在PROSPERO（CRD420211295223）注册。
结果：我们共纳入了17项研究，共有311名患者。高氧后观察到大脑乳酸值（合并的标准化平均差[SMD]-0.38[-0.53至-0.23]）和乳酸与丙酮酸比率值（合并的SMD-0.20[-0.35至-0.05]）的统计学显着降低。然而,高氧后，葡萄糖水平（合并SMD-0.08[-0.23至0.08]）保持不变。
结论：常压高氧可改善急性脑损伤患者的脑代谢紊乱。这种效应的临床影响需要进一步阐明。
方法：我们搜索了Medline和Scopus，遵循系统评价和荟萃分析声明的首选报告项目的建议；我们搜索了回顾性和前瞻性观察性研究，介入研究,和随机临床试验，对同时监测脑微透析的急性脑损伤患者进行高氧攻击。本研究在PROSPERO（CRD420211295223）注册。
结果：我们共纳入了17项研究，共有311名患者。高氧后观察到大脑乳酸值（合并的标准化平均差[SMD]-0.38[-0.53至-0.23]）和乳酸与丙酮酸比率值（合并的SMD-0.20[-0.35至-0.05]）的统计学显着降低。然而,高氧后，葡萄糖水平（合并SMD-0.08[-0.23至0.08]）保持不变。
结论：常压高氧可改善急性脑损伤患者的脑代谢紊乱。这种效应的临床影响需要进一步阐明。
