Mo Min, Liu Song-qiao, Yang Yi
Southeast University, Nanjing, Jiangsu, China.
Zhongguo Wei Zhong Bing Ji Jiu Yi Xue. 2011 Sep;23(9):513-7.
To demonstrate the effects of heat and moisture exchangers (HME) and heated humidifiers(HH) in preventing ventilator-associated pneumonia (VAP).
PubMed and Cochrane databases were searched by computer retrieval and manual retrieval to identify relevant randomized controlled trials (RCTs) using HMEs and HHs in preventing VAP from January 1st 1990 to September 1st 2010. Meta-analysis of HME and HH in preventing VAP was conducted using the methods recommended by the Cochrane Collaboration.
Eleven RCTs were included.
1 121 in HME group and 1 101 in HH group. In total, the rate of VAP in HME group and HH group was 14.2% (159/1 121) and 15.9% (175/1 101) respectively, the total relative risk (RR) was 0.88, and 95% confidence interval (95%CI) 0.72-1.07, P=0.21. Compared with HH group, there was not a reduction in the risk ratio of VAP in the HME group. Even in mechanical ventilation(MV) with a duration of at least 7 days for subgroup analysis (8 RCTs, sample size: 834 in HME group and 859 in HH group), the rate of VAP in HME group and HH group was 15.2% (127/834) and 17.5% (150/859) respectively, the total RR was 0.84, 95%CI 0. 58-1.23, P=0.37, suggesting that in MV with a duration at least 7 days, there was also no reduction in the risk ratio of VAP in the HME group.
This study suggests there is not a significant reduction in the incidence of VAP in patients humidified with HMEs during MV, even in patients ventilated for 7 days or longer. This finding is limited by lack of enough RCTs and blinding. Further large sample of high quality RCTs is necessary to examine the wider applicability of HMEs and their extended use.
探讨热湿交换器（HME）与加热湿化器（HH）在预防呼吸机相关性肺炎（VAP）中的作用。
通过计算机检索和手工检索PubMed及Cochrane数据库，以识别1990年1月1日至2010年9月1日期间使用HME和HH预防VAP的相关随机对照试验（RCT）。采用Cochrane协作网推荐的方法对HME和HH预防VAP进行Meta分析。
纳入11项RCT。
HME组1121例，HH组1101例。HME组和HH组VAP发生率分别为14.2%（159/1121）和15.9%（175/1101），总相对危险度（RR）为0.88，95%置信区间（95%CI）为0.72 - 1.07，P = 0.21。与HH组相比，HME组VAP风险比未降低。即使在机械通气（MV）时间至少7天的亚组分析中（8项RCT，样本量：HME组834例，HH组859例），HME组和HH组VAP发生率分别为15.2%（127/834）和17.5%（150/859），总RR为0.84，95%CI为0.58 - 1.23，P = 0.37，提示在MV时间至少7天的患者中，HME组VAP风险比也未降低。
本研究提示，在MV期间使用HME进行湿化的患者中，VAP发生率无显著降低，即使是通气7天或更长时间的患者。本研究结果因缺乏足够的RCT及盲法而受限。需要进一步开展大样本高质量RCT以检验HME更广泛的适用性及其延长使用情况。
