Melbourne Medical School, Faculty of Medicine Dentistry and Health Sciences, University of Melbourne, Internal Medicine Service, Ballarat Health Services, Ballarat, Vic, Australia.
J Hosp Infect. 2023 Oct;140:46-53. doi: 10.1016/j.jhin.2023.07.018. Epub 2023 Aug 4.
The risk of acquiring ventilator-associated pneumonia (VAP) increases with intensive care unit (ICU) length of stay (LOS). The objectives here are to estimate, using data derived from randomized concurrent control trials (RCCTs) of non-antimicrobial versus antimicrobial interventions, the relation of LOS with firstly, apparent VAP prevention effect, and secondly, with VAP incidence in control and intervention groups.
Control and intervention group data derived from 13 Cochrane reviews of 78 RCCTs of antimicrobial-based interventions versus 111 RCCTs of various non-antimicrobial-based VAP prevention interventions.
In meta-regression models of VAP prevention effect versus group mean LOS, the effect size of non-antimicrobial-based interventions regress towards the null (+0.028; +0.002 to +0.054) whereas antimicrobial-based interventions regress away from the null (-0.043; -0.08 to -0.004). The day 9-10 VAP incidence increase is 1.28 (0.97-1.6) percentage points among the control groups of antimicrobial interventions per day. By contrast, these increases among antimicrobial- (0.45; 0.19-0.71) and non-antimicrobial- (0.58; 0.29-0.87) intervention groups and in control groups of non-antimicrobial- (0.76; 0.46-1.05) interventions are all similar.
Antimicrobial-based versus non-antimicrobial-based interventions show overall greater apparent VAP prevention which is most apparent with longer group mean LOS. The basis for this surprising relationship with LOS resides, paradoxically, within the control rather than the intervention groups. This discrepancy implicates indirect (spill-over) effects, inapparent within individual antimicrobial-based RCCTs, which could spuriously conflate the appearance of VAP prevention.
重症监护病房（ICU）住院时间（LOS）的延长会增加呼吸机相关性肺炎（VAP）的风险。本研究的目的是使用非抗菌药物与抗菌药物干预的随机对照试验（RCCT）得出的数据来估计 LOS 与以下两个方面的关系：首先，明显的 VAP 预防效果，其次，控制组和干预组的 VAP 发生率。
从 78 项抗菌药物干预 RCCT 和 111 项各种非抗菌药物 VAP 预防干预 RCCT 的 13 项 Cochrane 综述中提取对照和干预组的数据。
在 VAP 预防效果与组均 LOS 的荟萃回归模型中，非抗菌药物干预的效应大小向零值回归（+0.028；+0.002 至+0.054），而抗菌药物干预则远离零值（-0.043；-0.08 至-0.004）。抗菌药物干预组对照组第 9-10 天 VAP 发病率增加 1.28（0.97-1.6）个百分点。相比之下，抗菌药物（0.45；0.19-0.71）和非抗菌药物（0.58；0.29-0.87）干预组以及非抗菌药物干预对照组（0.76；0.46-1.05）的这些增加则相似。
抗菌药物与非抗菌药物干预的总体预防 VAP 效果更好，这在组均 LOS 较长时更为明显。这种与 LOS 关系的奇怪之处在于，这种关系存在于对照组，而不是干预组。这种差异暗示了间接（溢出）效应，这些效应在单个抗菌药物 RCCT 中并不明显，但可能会错误地混淆 VAP 预防的效果。
