Paediatric ICU, Children's Hospital of Fudan University, Shanghai, China.
Clinical Microbiology Laboratory, Children's Hospital of Fudan University, Shanghai, China.
Clin Microbiol Infect. 2021 Mar;27(3):467.e1-467.e7. doi: 10.1016/j.cmi.2020.04.008. Epub 2020 Apr 17.
Ventilator-associated pneumonia (VAP) is a significant cause of prolonged hospital stay and increased mortality in mechanically ventilated children. Studies of the relationship between bacterial colonization of ventilator circuits (VCs) and VAP are lacking. This study aimed to investigate the role of bacterial colonization of VCs in the development of VAP, and to provide evidence for preventing VAP.
Mechanically ventilated patients admitted to the paediatric intensive care unit of a teaching hospital in China from October 2018 to November 2019 were enrolled. Specimens were collected from the VC and the patient's lower respiratory tract (LRT) for bacterial culture. Paired bacteria isolated from the VC and the patient's LRT, where colonization of the VC preceded that of the LRT, were evaluated for relatedness using pulsed field gel electrophoresis (PFGE).
A total of 114 patients were included; the incidence rate of VAP was 28.1% (32/114). A total of 1368 samples were collected from VCs; 16% had positive bacterial culture. There was no significant difference in bacterial colonization of VCs between VAP and non-VAP. In 13 patients, the LRT and VC were concurrently colonized with the same bacteria, where colonization of the VC occurred before colonization of the patient's LRT. PFGE results demonstrated high correlation between bacteria from the LRT and VC in 11 patients. Among 114 mechanically ventilated children, VAP caused by bacteria from the VC occurred in six patients, accounting for 18.8% (6/32) of the overall VAP rate in this study.
Bacterial colonization of the VC is a significant cause of VAP development in mechanically ventilated children. Preventive strategies for early identification and decontamination measures for contaminated VC may play a key role in preventing VAP.
呼吸机相关性肺炎（VAP）是导致机械通气患儿住院时间延长和死亡率增加的重要原因。目前缺乏关于呼吸机气路（VC）细菌定植与 VAP 之间关系的研究。本研究旨在探讨 VC 细菌定植在 VAP 发生发展中的作用，为预防 VAP 提供依据。
选取 2018 年 10 月至 2019 年 11 月在我国某教学医院儿科重症监护病房接受机械通气的患儿为研究对象。采集 VC 及患者下呼吸道（LRT）标本进行细菌培养。对 VC 和患者 LRT 中分离出的定植时间先后顺序为 VC 先于 LRT 的配对细菌，采用脉冲场凝胶电泳（PFGE）评估其相关性。
共纳入 114 例患儿，VAP 发生率为 28.1%（32/114）。共采集 VC 标本 1368 份，阳性率为 16%。VAP 与非 VAP 患儿 VC 细菌定植率无显著差异。13 例患者的 LRT 和 VC 同时被同一细菌定植，且 VC 定植时间先于患者 LRT 定植时间。11 例患者的 LRT 和 VC 细菌 PFGE 结果高度相关。在 114 例机械通气患儿中，6 例（占总体 VAP 发生率的 18.8%，6/32）由 VC 来源细菌引起的 VAP。
VC 细菌定植是导致机械通气患儿发生 VAP 的重要原因。对污染 VC 进行早期识别和清除的预防策略可能在预防 VAP 中发挥关键作用。
