Martin Daniel S, Mckenna Helen T, Rowan Kathryn M, Gould Doug W, Mouncey Paul R, Grocott Michael Pw, Harrison David A
Peninsula Medical School, University of Plymouth, Plymouth, UK.
Intensive Care Unit, University Hospitals Plymouth, Plymouth, UK.
J Intensive Care Soc. 2023 Nov;24(4):399-408. doi: 10.1177/17511437231192385. Epub 2023 Aug 23.
Oxygen is the commonest intervention provided to critically ill patients requiring mechanical ventilation. Despite this, it is unclear how much oxygen should be administered to patients in order to promote the best clinical outcomes and it has been suggested that a strategy of conservative oxygen therapy (COT) may be advantageous. We therefore sought to answer the question of whether COT versus usual or liberal oxygen therapy was beneficial to adult patients receiving mechanical ventilation on an intensive care unit (ICU) by performing a systematic review and meta-analysis.
Studies were included if they were randomised controlled trials comparing COT to liberal or usual oxygen therapy strategies in acutely ill adults (aged ⩾18 years) admitted to an ICU, and reported an outcome of interest. Studies were excluded if they were limited to a specific single disease diagnosis. The review was registered on PROSPERO (CRD42022308436). Risk of bias was assessed using a modified Cochrane Risk of Bias assessment tool. Effect estimates were pooled using a random effects model with the between study variance estimated using restricted maximum likelihood and standard errors calculated using the method of Hartung-Knapp/Sidik-Jonkman. Between study heterogeneity was quantified using the statistic. The certainty in the body of evidence was assessed using GRADE criteria.
Nine eligible studies with 5727 participants fulfilled all eligibility criteria. Trials varied in their definitions of COT and liberal or usual oxygen therapy. The pooled estimate of risk ratio for 90 day mortality for COT versus comparator was 0.99 (95% confidence interval 0.88-1.12, 95% prediction interval 0.82-1.21). There was low heterogeneity among studies ( = 22.4%). The finding that mortality was similar for patients managed with COT or usual/liberal oxygen therapy was graded as moderate certainty.
In critically ill adults admitted to an ICU, COT is neither beneficial nor harmful when compared to usual or liberal oxygen therapy. Trials to date have been inconsistent in defining both COT and liberal or usual oxygen therapy, which may have had an impact on the results of this meta-analysis. Future research should focus on unifying definitions and outcome measures.
对于需要机械通气的重症患者，吸氧是最常见的干预措施。尽管如此，目前尚不清楚应给予患者多少氧气以促进最佳临床结局，有人提出保守氧疗（COT）策略可能具有优势。因此，我们试图通过进行系统评价和荟萃分析来回答在重症监护病房（ICU）接受机械通气的成年患者中，COT与常规或宽松氧疗相比是否有益的问题。
纳入的研究需为随机对照试验，比较ICU中急性病成年患者（年龄≥18岁）的COT与宽松或常规氧疗策略，并报告感兴趣的结局。若研究仅限于特定单一疾病诊断则予以排除。该评价已在国际前瞻性注册系统（PROSPERO，注册号：CRD42022308436）登记。使用改良的Cochrane偏倚风险评估工具评估偏倚风险。采用随机效应模型汇总效应估计值，使用限制最大似然法估计研究间方差，并使用Hartung-Knapp/Sidik-Jonkman方法计算标准误。使用I²统计量量化研究间异质性。使用GRADE标准评估证据体的确定性。
9项符合条件的研究共5727名参与者满足所有纳入标准。各试验对COT以及宽松或常规氧疗的定义各不相同。COT与对照相比90天死亡率的风险比汇总估计值为0.99（95%置信区间0.88 - 1.12，95%预测区间0.82 - 1.21）。研究间异质性较低（I² = 22.4%）。COT治疗患者与常规/宽松氧疗患者死亡率相似这一发现被评为中等确定性。
在入住ICU的重症成年患者中，与常规或宽松氧疗相比，COT既无益处也无害处。迄今为止的试验在定义COT以及宽松或常规氧疗方面并不一致，这可能对本荟萃分析的结果产生了影响。未来的研究应侧重于统一定义和结局测量指标。
