Driving Pressure and Survival in the Acute Respiratory Distress Syndrome
Driving Pressure and Survival in the Acute Respiratory Distress Syndrome
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DOI：
10.1056/nejmsa1410639
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发表时间：
2015-02-19
影响因子：
158.5
通讯作者：
Brower, Roy G.
中科院分区：
文献类型：
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作者：
Amato, Marcelo B. P.;Meade, Maureen O.;Brower, Roy G.
使用较低的吸气末（平台）气道压、较低的潮气量（V-T）和较高的呼气末正压（PEEP）的机械通气策略可以提高急性呼吸窘迫综合征（ARDS）患者的生存率，但这些组成部分的相对重要性尚不确定。由于呼吸系统顺应性（C-RS）与疾病期间的通气剩余功能肺容量密切相关，（称为功能肺大小），我们假设驱动压力（Δ P=V-T/C-RS），其中V-T本质上标准化为功能肺大小（而不是预测的健康人的肺大小），是一个比V更能反映生存率的指标方法采用多水平中介分析的统计学方法对3562例患者的个体数据进行分析在9个先前报道的随机试验中，我们将Δ P作为与生存相关的独立变量进行了研究。在中介分析中，我们估计了随机呼吸机设置导致的Delta P变化的孤立效应，同时最大限度地减少了由于基线肺部疾病严重程度造成的混淆。Δ P值增加1个标准差（约7 cm水深）与死亡率增加相关（相对危险度，1.41; 95%可信区间[CI]，1.31 - 1.51; P
BACKGROUNDMechanical-ventilation strategies that use lower end-inspiratory (plateau) airway pressures, lower tidal volumes (V-T), and higher positive end-expiratory pressures (PEEPs) can improve survival in patients with the acute respiratory distress syndrome (ARDS), but the relative importance of each of these components is uncertain. Because respiratory-system compliance (C-RS) is strongly related to the volume of aerated remaining functional lung during disease (termed functional lung size), we hypothesized that driving pressure (Delta P=V-T/C-RS), in which V-T is intrinsically normalized to functional lung size (instead of predicted lung size in healthy persons), would be an index more strongly associated with survival than V-T or PEEP in patients who are not actively breathing.METHODSUsing a statistical tool known as multilevel mediation analysis to analyze individual data from 3562 patients with ARDS enrolled in nine previously reported randomized trials, we examined Delta P as an independent variable associated with survival. In the mediation analysis, we estimated the isolated effects of changes in Delta P resulting from randomized ventilator settings while minimizing confounding due to the baseline severity of lung disease.RESULTSAmong ventilation variables, Delta P was most strongly associated with survival. A 1-SD increment in Delta P (approximately 7 cm of water) was associated with increased mortality (relative risk, 1.41; 95% confidence interval [CI], 1.31 to 1.51; P