Menegueti Mayra Gonçalves, Auxiliadora-Martins Maria, Nunes Altacílio Aparecido
Escola de Enfermagem de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP Brazil ; Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto - USP, Divisão de Terapia Intensiva, Departamento de Cirurgia e Anatomia - 2o andar, Av. Bandeirantes, 3900 - Bairro Monte Alegre, Ribeirão Preto, SP Brazil.
Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto - USP, Divisão de Terapia Intensiva, Departamento de Cirurgia e Anatomia - 2o andar, Av. Bandeirantes, 3900 - Bairro Monte Alegre, Ribeirão Preto, SP Brazil.
BMC Anesthesiol. 2014 Dec 13;14:115. doi: 10.1186/1471-2253-14-115. eCollection 2014.
Patients may acquire ventilator-associated pneumonia (VAP) by aspirating the condensate that originates in the ventilator circuit upon use of a conventional humidifier. The bacteria that colonize the patients themselves can proliferate in the condensate and then return to the airways and lungs when the patient aspirates this contaminated material. Therefore, the use of HME might contribute to preventing pneumonia and lowering the VAP incidence. The aim of this study was to evaluate how the use of HME impacts the probability of VAP occurrence in critically ill patients.
On the basis of the acronym "PICO" (Patient, Intervention, Comparison, Outcome), the question that guided this review was "Do critically ill patients under invasive mechanical ventilation present lower VAP incidence when they use HME as compared with HH?". Two of the authors of this review searched the databases PUBMED/Medline, The Cochrane Library, and Latin-American and Caribbean Literature in Health Sciences, LILACS independently; they used the following keywords: "heat and moisture exchanger", AND "heated humidifier", AND "ventilator-associated pneumonia prevention". This review included papers in the English language published from January 1990 to December 2012.
This review included ten studies. Comparison between the use of HME and HH did not reveal any differences in terms of VAP occurrence (OR = 0.998; 95% CI: 0.778-1.281). Together, the ten studies corresponded to a total sample of 1077 and 953 patients in the HME and HH groups, respectively; heterogeneity among the investigations was low (I(2) < 50%). Information about the outcome mortality was available in only eight of the ten studies. The use of HME and HH did not afford different results in terms of mortality (OR = 1.09; 95% CI: 0.864-1.376). The total sample size was 884 and 762 patients, respectively. Heterogeneity among the studies was low (I(2) = 0.0%).
Current meta-analysis was not sufficient to definitely exclude an associate between heat and moisture exchangers and VAP. Despite the methodological limitations found in selected clinical trials, the current meta-analysis suggests that HME does not decrease VAP incidence or mortality in critically ill patients.
患者在使用传统加湿器时，可能会吸入呼吸机回路中产生的冷凝水，从而患上呼吸机相关性肺炎（VAP）。定植于患者自身的细菌可在冷凝水中繁殖，然后当患者吸入这种受污染物质时，细菌又会回到气道和肺部。因此，使用热湿交换器（HME）可能有助于预防肺炎并降低VAP的发生率。本研究的目的是评估使用HME对重症患者发生VAP概率的影响。
基于“PICO”（患者、干预措施、对照、结局）这一缩写词，指导本综述的问题是“与使用加热加湿器（HH）相比，接受有创机械通气的重症患者使用HME时VAP发生率是否更低？”。本综述的两位作者分别独立检索了数据库PUBMED/Medline、Cochrane图书馆以及拉丁美洲和加勒比地区卫生科学文献数据库LILACS；他们使用了以下关键词：“热湿交换器”、“加热加湿器”、“预防呼吸机相关性肺炎”。本综述纳入了1990年1月至2012年12月发表的英文论文。
本综述纳入了十项研究。使用HME和HH之间在VAP发生方面未发现任何差异（比值比[OR]=0.998；95%置信区间[CI]：0.778 - 1.281）。十项研究中，HME组和HH组的总样本量分别为1077例和953例患者；研究间的异质性较低（I²<50%）。在十项研究中，仅有八项研究提供了关于死亡率结局的信息。在死亡率方面，使用HME和HH未得出不同结果（OR = 1.09；95% CI：0.864 - 1.376）。总样本量分别为884例和762例患者。研究间的异质性较低（I² = 0.0%）。
当前的荟萃分析不足以明确排除热湿交换器与VAP之间的关联。尽管在所选临床试验中发现了方法学上的局限性，但当前的荟萃分析表明，HME不会降低重症患者的VAP发生率或死亡率。
