心脏瓣膜手术后呼吸机相关肺炎的临床与病原学分析

Clinical and etiological analysis of ventilator-associated pneumonia in adult patients following heart valve surgery

目的分析心脏瓣膜手术后发生呼吸机相关肺炎(VAP)的临床及病原学特点。方法分析本院成年心脏瓣膜手术患者临床资料、病原学特点和发生VAP的危险因素。结果77例患者心脏瓣膜手术后发生VAP34例,发生率为44.2%,其中早发VAP11例,晚发VAP23例。多因素分析表明重度肺动脉高压、手术时体外循环≥120min、红细胞输注≥6u、氧合指数(PaO2/FiO2)≤300mmHg、机械通气时间大于4d、气管切开是VAP发生的危险因素。早发VAP与晚发VAP痰培养病原菌差异有统计学意义(χ2=7.034,P=0.030),早发VAP痰培养病原菌以革兰阳性菌为主,占69.2%,晚发VAP则以革兰阴性菌及真菌为主,分别占45.5%及27.3%。结论严重肺动脉高压、长时间体外循环、红细胞大量输注、术后低氧血症、长时间机械通气及气管切开是心脏瓣膜术后VAP发生的危险因素。术后早发VAP与晚发VAP痰病原菌有一定的差异。

Objective The aim of this study was to investigate the clinical characteristics of ventilator-associated pneumonia （VAP） and the pathogens in adult patients undergoing heart valve surgery of cardiopulmonary bypass （CPB）. Methods The clinical data,pathogen pattern and associated risk factors of VAP were analyzed in adult patients following heart valve surgery.Results Of the 77 patients following heart valve surgery,34 developed VAP. The incidence was 44.2%. Of these 34 cases,11 were early-onset VAP and 23 were late-onset VAP. Multivariate analysis indicated that severe pulmonary hypertension,CPB time 〉120 min,transfusion of red blood cell ≥ 6 u,PaO2/FiO2 ≤300 mmHg,ventilation time ≥ 4 days and tracheotomy were significant risk factors of VAP. The proportion of gram-positive bacteria （69.2%） was significantly higher in early-onset VAP sputum culture,while the proportion of gram-negative bacteria （45.5%） and fungus （27.3%） were significantly higher in late-onset VAP （χ ^2 =7.034,P=0.030）. Conclusions This study shows that the severe pulmonary hypertension,longer CPB time,longer ventilation time,hypoxemia,red blood cell transfusion and tracheotomy are risk factors most likely associated with development of VAP in adult patients following heart valve surgery. There is difference in the sputum pathogens between early-onset and late-onset VAP.