Chen Xiao-Li, Zhang Bei-Lei, Meng Chang, Huang Hui-Bin, Du Bin
Department of Critical Care Medicine, the First Affiliated Hospital of Fujian Medical University, Fuzhou, China.
Department of Critical Care Medicine, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, 102218, China.
J Intensive Care. 2021 Jul 22;9(1):47. doi: 10.1186/s40560-021-00563-7.
Conservative oxygen strategy is recommended in acute illness while its benefit in ICU patients remains controversial. Therefore, we sought to conduct a systematic review and meta-analysis to examine such oxygen strategies' effect and safety in ICU patients.
We searched PubMed, Embase, and the Cochrane database from inception to Feb 15, 2021. Randomized controlled trials (RCTs) that compared a conservative oxygen strategy to a conventional strategy in critically ill patients were included. Results were expressed as mean difference (MD) and risk ratio (RR) with a 95% confidence interval (CI). The primary outcome was the longest follow-up mortality. Heterogeneity, sensitivity analysis, and publication bias were also investigated to test the robustness of the primary outcome.
We included seven trials with a total of 5265 patients. In general, the conventional group had significantly higher SpO or PaO than that in the conservative group. No statistically significant differences were found in the longest follow-up mortality (RR, 1.03; 95% CI, 0.97-1.10; I=18%; P=0.34) between the two oxygen strategies when pooling studies enrolling subjects with various degrees of hypoxemia. Further sensitivity analysis showed that ICU patients with mild-to-moderate hypoxemia (PaO/FiO >100 mmHg) had significantly lower mortality (RR, 1.24; 95% CI, 1.05-1.46; I=0%; P=0.01) when receiving conservative oxygen therapy. These findings were also confirmed in other study periods. Additional, secondary outcomes of the duration of mechanical ventilation, the length of stay in the ICU and hospital, change in sequential organ failure assessment score, and adverse events were comparable between the two strategies.
Our findings indicate that conservative oxygen therapy strategy did not improve the prognosis of the overall ICU patients. The subgroup of ICU patients with mild to moderate hypoxemia might obtain prognosis benefit from such a strategy without affecting other critical clinical results.
急性病患者推荐采用保守氧疗策略，但其对重症监护病房（ICU）患者的益处仍存在争议。因此，我们试图进行一项系统评价和荟萃分析，以检验此类氧疗策略对ICU患者的疗效和安全性。
我们检索了从数据库建立至2021年2月15日的PubMed、Embase和Cochrane数据库。纳入比较危重症患者保守氧疗策略与传统策略的随机对照试验（RCT）。结果以平均差（MD）和风险比（RR）及95%置信区间（CI）表示。主要结局是最长随访期死亡率。还进行了异质性、敏感性分析和发表偏倚检验，以检验主要结局的稳健性。
我们纳入了7项试验，共5265例患者。总体而言，传统组的SpO或PaO显著高于保守组。纳入不同程度低氧血症受试者的研究进行汇总分析时，两种氧疗策略在最长随访期死亡率方面无统计学显著差异（RR，1.03；95%CI，0.97 - 1.10；I² = 18%；P = 0.34）。进一步的敏感性分析表明，轻至中度低氧血症（PaO₂/FiO₂ > 100 mmHg）的ICU患者接受保守氧疗时死亡率显著更低（RR，1.24；95%CI，1.05 - 1.46；I² = 0%；P = 0.01）。这些结果在其他研究时间段也得到了证实。此外，两种策略在机械通气时间、ICU和医院住院时间、序贯器官衰竭评估评分变化及不良事件等次要结局方面相当。
我们的研究结果表明，保守氧疗策略并未改善整体ICU患者的预后。轻至中度低氧血症的ICU患者亚组可能从此类策略中获得预后益处，且不影响其他关键临床结果。
