目的 探究先天性心脏病(简称先心病)患儿术后呼吸机相关性肺炎(VAP)的病原菌分布、药敏情况及危险因素,为先心病术后VAP的防治提供临床依据。方法 根据VAP的发生情况,将2012年1月至2014年12月行先心病手术后机械通气时间超过48 h的312例患儿分为VAP组(n=53)和非VAP组(n=259)。采集VAP患儿的痰标本进行病原菌培养及相关药物敏感性试验;应用logistic回归分析先心病患儿术后发生VAP的危险因素。结果 53例VAP患儿的痰培养阳性者51例,共培养出阳性菌株63株,其中革兰阴性菌49株(78%),革兰阳性菌9株(14%),真菌5株(8%)。药敏试验结果显示革兰阴性菌对阿莫西林、哌拉西林、头孢噻肟及头孢他啶等耐药率较高(总耐药率>74%),而对阿米卡星、多粘菌素及美洛培南较敏感(总耐药率19%~32%)。单因素分析发现两组在白蛋白水平、术前抗生素使用情况、机械通气时间、插管次数、镇痛时间、体外循环时间、主动脉阻断时间及是否使用H2受体阻断剂等方面比较,差异有统计学意义(P<0.05);Logistic回归分析显示,白蛋白水平<35 g/L、机械通气时间≥7 d、插管次数≥3次、体外循环时间≥100 min及主动脉阻断时间≥60 min为先心病患儿术后VAP发生的独立危险因素(P<0.05)。结论 革兰阴性菌为先心病术后VAP的主要致病菌;临床上应根据病原菌分布及药敏试验结果,合理选用抗生素;同时根据VAP发生的危险因素,积极采取综合防治措施,降低先心病患儿术后VAP的发病率。

Objective To investigate the distribution and drug sensitivity of pathogens and risk factors for ventilator-associated pneumonia (VAP) in children with congenial heart disease (CAD) after surgery. Methods According to the occurrence of VAP, 312 children with CAD who received mechanical ventilation after surgery for 48 hours or longer between January 2012 and December 2014 were classified into VAP (n=53) and non-VAP groups (n=259). Sputum samples were collected and cultured for pathogens in children with VAP. The drug sensitivity of pathogens was analyzed. The risk factors for postoperative VAP were identified by multiple logistic regression analysis. Results The sputum cultures were positive in 51 out of 53 children with VAP, and a total of 63 positive strains were cultured, including 49 strains of Gram-negative bacteria (78%), 9 strains of Gram-positive bacteria (14%) and 5 strains of funqi (8%). The drug sensitivity test showed that Gram-negative bacteria were resistant to amoxicillin, piperacillin, cefotaxime and ceftazidime, with a resistance rate of above 74%, and demonstrated a sensitivity to amikacin, polymyxin and meropenem (resistance rate of 19%-32%). Single factor analysis showed albumin levels, preoperative use of antibiotics, duration of mechanical ventilation, times of tracheal intubation, duration of anesthesia agent use, duration of acrdiopulmonary bypass, duration of aortic occlusion and use of histamin2-receptor blockade were significantly different between the VAP and non-VAP groups (P<0.05). The multiple logistic regression showed albumin levels (<35 g/L), duration of mechanical ventilation (≥7 d), times of tracheal intubation (≥3), duration of acrdiopulmonary bypass (≥100 minutes) and duation of aortic occlusion (≥60 minutes) were independent risk factors for VAP in children with CAD after surgery. Conclusions Gram-nagative bacteria are main pathogens for VAP in children with CAD after surgery. The antibiotics should be used based on the distribution of pathogens and drug sensitivity test results of pathogens. The effective measures for prevention of VAP should be taken according to the related risk factors for VAP to reduce the morbidity of VAP in children with CAD after surgery.