呼吸机相关性肺炎病原学与细菌耐药性变迁的临床研究

目的调查安徽省铜陵市人民医院近10年来呼吸机相关性肺炎（VAP）病原学构成与细菌耐药性的变迁。方法比较两个不同时间段（1996年6月～2001年6月和2001年7月～2006年6月）病原学分布特点及细菌耐药性的变迁。结果10年间，有完整病历资料、接受有创机械通气的患者共1236例，VAP发生率为44．34％（538／1236）；在538例VAP中，2种及2种以上致病菌感染占56．51％；革兰阴性细菌中，铜绿假单胞菌和不动杆菌属为VAP的主要致病菌（68．63％）（385／561）；表皮葡萄球菌感染为VAP的主要革兰阳性致病菌（75．40％）（95／126）；真菌占20．98％（183／872）；铜绿假单胞菌在两个时间段所占比例无明显变化，不动杆菌属的检出率呈上升趋势（8．23％～15．23％）；铜绿假单胞菌和不动杆菌属对亚胺培南、头孢他啶的敏感性明显下降，耐苯唑西林表皮葡萄球菌的检出率显著升高（18．75％～71．43％）。结论铜绿假单胞菌和不动杆菌属是我院VAP的主要革兰阴性致病菌，10年间，致病菌的分布及细菌耐药菌性已经发生了明显的变化，临床初始经验性治疗面临更大的难度。

Pathogens distribution and the changes of antibiotic resistance for ventilator-associated pneumonia:a retrospective clinical study

Objective To investigate the etiology of ventilator-associated pneumonia （VAP） in the people＇s hospital of tong, ling city, Anhui province, and to explore the anfimierobial resistance of predominant pathogens in the last 10 years, and to provide the reasonable antimicrobial strategy based on the local distribution of pathogens. Methods A retrospective observational study was used. From June 1996 to June 2006, totally 538 cases with VAP were collected for analyzing 1236 mechanical ventilation （ 〉 48 h） patients. The pathogens distribution and the changes of antibiotic resistance were compared from June 1996 to June 2001 from July 2001 to June 2006,respectively. Standard disk diffusion susceptibility tests were performed on the predominant pathogens. Results During this period, the incidence of VAP was 44. 34% ,304 cases were infected by two or more pathogens （538 VAP cases）. The main pathogens of VAP were Gram negative organisms （68.63%） whose predominant pathogens were Pseudomonas aeruginosa and Acinetobacter. On the other hand, 75.40% of Gram positive organisms were Staphylococcus epidermidis. Of the pathogens 20. 98% were eumycetes. No significant differences were found for the incidence rate of P. aeruginosa in the 2 stages. During the recent 10 years,the incidence of Acinetobacter rose up from 8.23% to 15.23% and the rate of oxacillin-resistant Staphylococcus epidermidis rose up from 18.75% to 71.43%. The sensitivity of P. aeruginosa and Acinetobacter isolates descended to sodium imipenem cilastatin and ceftazidime in the past 10 years. Conclusion The main Gram negative pathogens of VAP in our hospital are P. aeruginosa and Acinetobacter,and an remarkable changes in pathogens distribution and infection spectrum have been taking place during the past 10 years. The selection of initial experimental antimicrobial strategy will face a great challenge.