In patients with acute respiratory distress syndrome (ARDS), lung recruitment could be maximised with the use of recruitment manoeuvres (RM) or applying a positive end-expiratory pressure (PEEP) higher than what is necessary to maintain minimal adequate oxygenation. We aimed to determine whether ventilation strategies using higher PEEP and/or RMs could decrease mortality in patients with ARDS. We searched MEDLINE, EMBASE and CENTRAL from 1996 to December 2019, included randomized controlled trials comparing ventilation with higher PEEP and/or RMs to strategies with lower PEEP and no RMs in patients with ARDS. We computed pooled estimates with a DerSimonian-Laird mixed-effects model, assessing mortality and incidence of barotrauma, population characteristics, physiologic variables and ventilator settings. We performed a trial sequential analysis (TSA) and a meta-regression. Excluding two studies that used tidal volume (VT) reduction as co-intervention, we included 3870 patients from 10 trials using higher PEEP alone (n = 3), combined with RMs (n = 6) or RMs alone (n = 1). We did not observe differences in mortality (relative risk, RR 0.96, 95% confidence interval, CI [0.84–1.09], p = 0.50) nor in incidence of barotrauma (RR 1.22, 95% CI [0.93–1.61], p = 0.16). In the meta-regression, the PEEP difference between intervention and control group at day 1 and the use of RMs were not associated with increased risk of barotrauma. The TSA reached the required information size for mortality (n = 2928), and the z-line surpassed the futility boundary. At low VT, the routine use of higher PEEP and/or RMs did not reduce mortality in unselected patients with ARDS. PROSPERO CRD42017082035.

中文翻译：

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较高 PEEP 和复张操作对 ARDS 患者死亡率的影响：随机对照试验的系统评价、荟萃分析、荟萃回归和试验序贯分析

在急性呼吸窘迫综合征 (ARDS) 患者中，可以通过使用肺复张动作 (RM) 或应用高于维持最低充足氧合所需的呼气末正压 (PEEP) 来最大化肺复张。我们旨在确定使用较高 PEEP 和/或 RM 的通气策略是否可以降低 ARDS 患者的死亡率。我们检索了 1996 年至 2019 年 12 月的 MEDLINE、EMBASE 和 CENTRAL，包括比较具有较高 PEEP 和/或 RMs 的通气策略与具有较低 PEEP 且无 RMs 的策略在 ARDS 患者中的随机对照试验。我们使用 DerSimonian-Laird 混合效应模型计算汇总估计值，评估气压伤的死亡率和发生率、人口特征、生理变量和呼吸机设置。我们进行了试验序贯分析 (TSA) 和元回归。排除两项使用潮气量 (VT) 降低作为共同干预措施的研究，我们纳入了来自 10 项单独使用较高 PEEP（n = 3）、结合 RMs（n = 6）或 RMs（n = 1）的试验中的 3870 名患者。我们没有观察到死亡率（相对风险，RR 0.96，95% 置信区间，CI [0.84–1.09]，p = 0.50）和气压伤发生率（RR 1.22，95% CI [0.93–1.61]，p = 0.16）。在元回归中，干预组和对照组在第 1 天的 PEEP 差异以及 RM 的使用与气压伤风险增加无关。TSA 达到了死亡率所需的信息量 (n = 2928)，z 线超出了无效边界。在低VT时，常规使用较高的 PEEP 和/或 RMs 并没有降低未经选择的 ARDS 患者的死亡率。PROSPERO CRD42017082035。