Effects of a clinical trial on mechanical ventilation practices in patients with acute lung injury
Effects of a clinical trial on mechanical ventilation practices in patients with acute lung injury
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DOI：
10.1164/rccm.200709-1424oc
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发表时间：
2008-06-01
影响因子：
24.7
通讯作者：
Thompson, B. Taylor
中科院分区：
文献类型：
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作者：
Checkley, William;Brower, Roy;Thompson, B. Taylor
理由：在急性呼吸窘迫综合征网络（ARDSNet）的一项临床试验中，潮汐量为6 ml/kg的机械通气降低了急性肺损伤的死亡率。然而，对这些结果的解释引起了争议，目前尚不清楚这项试验是否会改变常规护理实践。目的：首先，确定潮气量试验后，ARDSNet医院的临床实践是否发生了变化。其次，确定随机分组前48小时内的潮气量和平台压（Pplat）是否影响随后以6 ml/kg预测体重（PBW）管理的患者的住院死亡率。方法：我们使用了6项试验（1996-2005）2451例患者的入组前数据来描述潮气量随时间的变化。我们使用逻辑回归来确定入组前的潮汐量或Pplat是否影响死亡率。测量和主要结果：入组前潮气量中位数从潮气量试验期间（1996-1999）的10.3 ml/kg PBW（范围4.3-17.1）下降到试验结束后的7.3 ml/kg PBW（范围3.9-16.2）（P < 0.001）。入组前潮气量与死亡率无相关性（P = 0.566）。入组前Pplat每增加1 cm H2O，死亡几率成倍增加（P< 0.001）（例如，入组前Pplat每增加10 cm H2O，死亡几率增加1.37倍）。结论：在潮汐量试验发表后，医生使用较低的潮汐量。入组前Pplat与死亡率密切相关，并可能独立于潮汐量反映疾病的严重程度。在考虑潮气量后，在急性肺损伤过程早期测量的Pplat是一个呼吸系统特异性值，具有很强的预后意义。
Rationale: In a clinical trial by the Acute Respiratory Distress Syndrome Network (ARDSNet), mechanical ventilation with tidal volumes of 6 ml/kg decreased mortality from acute lung injury. However, interpretations of these results generated controversy and it was unclear if this trial would change usual-care practices.Objectives: First, to determine if clinical practices at ARDSNet hospitals changed after the tidal volume trial. Second, to determine if tidal volume and plateau pressure (Pplat) within 48 hours before randomization affected hospital mortality in patients subsequently managed with 6 ml/kg predicted body weight (PBW).Methods: We used preenrollment data from 2,451 patients enrolled in six trials (1996-2005) to describe changes in tidal volume over time. We used logistic regression to determine if preenrollment tidal volume or Pplat affected mortality.Measurements and Main Results: Median preenrollment tidal volume decreased from 10.3 ml/kg PBW (range, 4.3-17.1) during the tidal volume trial (1996-1999) to 7.3 ml/kg PBW (range, 3.9-16.2) after its completion (P < 0.001). Preenrollment tidal volume was not associated with mortality (P = 0.566). The odds of death increased multiplicatively with each cm H2O of preenrollment Pplat (P< 0.001) (e.g., the odds of death was 1.37 times greater when preenrollment Pplat increased by 10 cm H2O).Conclusions: Physicians used lower tidal volumes after publication of the tidal volume trial. Preenrollment Pplat was strongly associated with mortality, and may reflect disease severity independent of tidal volume. Pplat measured early in the course of acute lung injury, after accounting for tidal volume, is a respiratory system-specific value with strong prognostic significance.