Berton Danilo Cortozi, Kalil Andre C, Teixeira Paulo José Zimermann
Department of Pulmonary Medicine - Pavilhão Pereira Filho - Santa Casa de Porto Alegre, Federal University of Health Sciences of Porto Alegre (UFCSPA) and Feevale University, Rua Prof Annes Dias, 295, Porto Alegre, Rio Grande do Sul, Brazil, CEP 90020-090.
Cochrane Database Syst Rev. 2014 Oct 30;2014(10):CD006482. doi: 10.1002/14651858.CD006482.pub4.
Ventilator-associated pneumonia (VAP) is a common infectious disease in intensive care units (ICUs). The best diagnostic approach to resolve this condition remains uncertain.
To evaluate whether quantitative cultures of respiratory secretions and invasive strategies are effective in reducing mortality in immunocompetent patients with VAP, compared with qualitative cultures and non-invasive strategies. We also considered changes in antibiotic use, length of ICU stay and mechanical ventilation.
We searched CENTRAL (2014, Issue 9), MEDLINE (1966 to October week 2, 2014), EMBASE (1974 to October 2014) and LILACS (1982 to October 2014).
Randomised controlled trials (RCTs) comparing respiratory samples processed quantitatively or qualitatively, obtained by invasive or non-invasive methods from immunocompetent patients with VAP and which analysed the impact of these methods on antibiotic use and mortality rates.
Two review authors independently reviewed the trials identified in the search results and assessed studies for suitability, methodology and quality. We analysed data using Review Manager software. We pooled the included studies to yield the risk ratio (RR) for mortality and antibiotic change with 95% confidence intervals (CI).
Of the 5064 references identified from the electronic databases (605 from the updated search in October 2014), five RCTs (1367 patients) met the inclusion criteria. Three studies compared invasive methods using quantitative cultures versus non-invasive methods using qualitative cultures, and we used them to answer the main objective of this review. The other two studies compared invasive versus non-invasive methods, both using quantitative cultures. We combined all five studies to compare invasive versus non-invasive interventions for diagnosing VAP. The studies that compared quantitative and qualitative cultures (1240 patients) showed no statistically significant differences in mortality rates (RR 0.91; 95% CI 0.75 to 1.11). The analysis of all five RCTs showed there was no evidence of reduction in mortality in the invasive group versus the non-invasive group (RR 0.93; 95% CI 0.78 to 1.11). There were no significant differences between the interventions with respect to the number of days on mechanical ventilation, length of ICU stay or antibiotic change.
AUTHORS' CONCLUSIONS: There is no evidence that the use of quantitative cultures of respiratory secretions results in reduced mortality, reduced time in ICU and on mechanical ventilation, or higher rates of antibiotic change when compared to qualitative cultures in patients with VAP. We observed similar results when invasive strategies were compared with non-invasive strategies.
呼吸机相关性肺炎（VAP）是重症监护病房（ICU）常见的感染性疾病。解决这一问题的最佳诊断方法仍不明确。
与定性培养和非侵入性策略相比，评估呼吸道分泌物定量培养和侵入性策略在降低免疫功能正常的VAP患者死亡率方面是否有效。我们还考虑了抗生素使用、ICU住院时间和机械通气时间的变化。
我们检索了Cochrane系统评价数据库（CENTRAL，2014年第9期）、医学期刊数据库（MEDLINE，1966年至2014年10月第2周）、荷兰医学文摘数据库（EMBASE，1974年至2014年10月）和拉丁美洲及加勒比地区卫生科学数据库（LILACS，1982年至2014年10月）。
随机对照试验（RCT），比较通过侵入性或非侵入性方法从免疫功能正常的VAP患者获得的呼吸道样本进行定量或定性处理，并分析这些方法对抗生素使用和死亡率的影响。
两位综述作者独立审查检索结果中确定的试验，并评估研究的适用性、方法和质量。我们使用Review Manager软件分析数据。我们汇总纳入的研究，得出死亡率和抗生素变化的风险比（RR）及95%置信区间（CI）。
从电子数据库中识别出5064篇参考文献（2014年10月更新检索得到605篇），5项RCT（1367例患者）符合纳入标准。3项研究比较了使用定量培养的侵入性方法与使用定性培养的非侵入性方法，我们用它们来回答本综述的主要问题。另外2项研究比较了均使用定量培养的侵入性与非侵入性方法。我们合并所有5项研究以比较诊断VAP的侵入性与非侵入性干预措施。比较定量和定性培养的研究（1240例患者）显示死亡率无统计学显著差异（RR 0.91；95%CI 0.75至1.11）。对所有5项RCT的分析表明，侵入性组与非侵入性组相比，没有证据表明死亡率降低（RR 0.93；95%CI 0.78至1.11）。干预措施在机械通气天数、ICU住院时间或抗生素更换方面无显著差异。
没有证据表明，与VAP患者的定性培养相比，使用呼吸道分泌物定量培养可降低死亡率、缩短ICU和机械通气时间或提高抗生素更换率。当比较侵入性策略与非侵入性策略时，我们观察到了类似的结果。
