Lancet Infect Dis：呼吸机相关性肺炎归因死亡率

　　4月25日在线发表于《柳叶刀• 传染病学》（Lancet Infect Dis）杂志的一项荟萃研究显示，呼吸机相关性肺炎的总体归因死亡率为13%，外科亚组和入院时严重程度评分为中度的患者死亡率更高。归因性死亡主要是由在ICU住院时间增加造成暴露于死亡风险的时间延长而引起的。

　　各种混杂因素、样本量小和难于进行相关的亚组分析阻碍了对呼吸机相关性肺炎归因死亡率的评估。该研究应用公布的呼吸机相关性肺炎预防随机试验的原始个体患者数据对归因死亡率进行了评估。

　　研究人员通过系统性回顾确定了相关研究。研究人员通过单级荟萃分析和竞争风险分析对个体患者的数据进行了分析。预先设定的亚组包括外科、创伤和内科患者，以及疾病评分严重程度不同的患者。

　　结果，研究共获取了来自24个试验的6284名个体患者的数据。总体归因死亡率为13%，外科亚组和入院时严重程度评分为中度的患者死亡率更高。创伤亚组、内科亚组和疾病评分严重程度为低度或重度患者的归因死亡率接近0。研究人员对来自19项研究的5162例患者进行了竞争风险分析，患呼吸器相关性肺炎后在重症监护病房（ICU）内死亡的总体日常风险比为1.13。患呼吸机相关性肺炎后出院的总体日常风险为0.74，这使得患者死在ICU的总体累积风险比达2.20。外科亚组（HR为2.97）入院时严重程度评分为中度的患者（HR为2.49）死于呼吸机相关性肺炎的累积风险最高。

与肺炎相关的拓展阅读：

• 浙江创人工肝技术治H7N9禽流感患者肺炎好转
• ERJ：肥胖可能降低肺炎住院患者的死亡率
• 浙首创人工肝技术治H7N9首用者肺炎好转
• Am J Med：肺炎长期危害或重于心脏病
• Stroke：天坛医院研发新量表用于预测脑梗死后相关院内肺炎 更多信息请点击：有关肺炎更多资讯

Attributable mortality of ventilator-associated pneumonia: a meta-analysis of individual patient data from randomised prevention studies
Background
Estimating attributable mortality of ventilator-associated pneumonia has been hampered by confounding factors, small sample sizes, and the difficulty of doing relevant subgroup analyses. We estimated the attributable mortality using the individual original patient data of published randomised trials of ventilator-associated pneumonia prevention.
Methods
We identified relevant studies through systematic review. We analysed individual patient data in a one-stage meta-analytical approach (in which we defined attributable mortality as the ratio between the relative risk reductions [RRR] of mortality and ventilator-associated pneumonia) and in competing risk analyses. Predefined subgroups included surgical, trauma, and medical patients, and patients with different categories of severity of illness scores.
Findings
Individual patient data were available for 6284 patients from 24 trials. The overall attributable mortality was 13%, with higher mortality rates in surgical patients and patients with mid-range severity scores at admission (ie, acute physiology and chronic health evaluation score [APACHE] 20—29 and simplified acute physiology score [SAPS 2] 35—58). Attributable mortality was close to zero in trauma, medical patients, and patients with low or high severity of illness scores. Competing risk analyses could be done for 5162 patients from 19 studies, and the overall daily hazard for intensive care unit (ICU) mortality after ventilator-associated pneumonia was 1·13 (95% CI 0·98—1·31). The overall daily risk of discharge after ventilator-associated pneumonia was 0·74 (0·68—0·80), leading to an overall cumulative risk for dying in the ICU of 2·20 (1·91—2·54). Highest cumulative risks for dying from ventilator-associated pneumonia were noted for surgical patients (2·97, 95% CI 2·24—3·94) and patients with mid-range severity scores at admission (ie, cumulative risks of 2·49 [1·81—3·44] for patients with APACHE scores of 20—29 and 2·72 [1·95—3·78] for those with SAPS 2 scores of 35—58).
Interpretation
The overall attributable mortality of ventilator-associated pneumonia is 13%, with higher rates for surgical patients and patients with a mid-range severity score at admission. Attributable mortality is mainly caused by prolonged exposure to the risk of dying due to increased length of ICU stay.
Funding
None.