呼吸机相关性肺炎病原菌分布及其耐药性分析

目的明确呼吸机相关性肺炎(VAP)病原菌的流行分布及耐药特点。方法对气管切开并实施机械通气>48 h的261例患者下呼吸道分泌物,进行细菌定量培养及抗菌药物敏感性测定。结果从气管切开至发生VAP的时间为3~126 d,平均18.2 d;发生VAP 92例,发生率为35.2%,死亡率为35.9%;92例VAP患者下呼吸道分泌物培养出病原菌276株,病原菌种分布:革兰阴性杆菌170株,占61.6%,主要为假单胞菌属、不动杆菌属、克雷伯菌属、肠杆菌属;革兰阳性球菌57株,占20.6%,主要为金黄色葡萄球菌、表皮葡萄球菌、肠球菌属,真菌感染占17.8%,主要为假丝酵母菌属;各类病原菌混合感染者88.0%,主要病原菌药敏试验结果,革兰阴性杆菌对亚胺培南总敏感性最高,其次为头孢哌酮/舒巴坦、阿米卡星、环丙沙星、替卡西林/克拉维酸、头孢他啶,对氨苄西林、第二代头孢菌素、头孢噻肟、头孢曲松则有较高的耐药性;金黄色葡萄球菌耐药现象严重,对青霉素、苯唑西林的耐药率分别达100.0%、91.3%,但对万古霉素、替考拉宁尚敏感。结论VAP的主要病原菌为革兰阴性杆菌且存在较严重的耐药现象,混合感染现象严重,应引起临床高度重视。

Distribution and Drug-resistance of Pathogens in Patients with Ventilator-associated Pneumonia

OBJECTIVE To investigate the prevalence and the drug-resistance of pathogens in patients with ventilator-associated pneumonia(VAP).METHODS The secretion of lower respiratory tract of 261 patients receiving tracheostomy and mechanical ventilation for more than 48 hours was cultured with a quantitative method and their antibiotic susceptibility was detected by standard K-B methods.RESULTS The onset time of VAP was 3-126 days(means 18.2 days) after using mechanical ventilation.The incidence of VAP was 35.2%.The mortality of VAP was 35.9%.Gram-negative bactilli(GNB) were the main pathogens in VAP.Among 276 strains of pathogens collected,the GNB occupied 61.6%,the Gram-positive bacteria(GPB) were 20.6%,and the fungi were 17.8%.Among the GNB,Pseudomonas,Acinetobacter,Klebsiella and Enterobacter were the main pathogens.Among the GPB,Staphylococcus aureus,S.epidermidis and Enterococcus were the main pathogens.Meticillin-resistanet S.aureus(MRSA) accounted for 91.3% in S.aureus.Candida albicans was the main fungus.The mixed infections attained to 88.0%.The antibiotic susceptibility test results showed that GNB was highly susceptible to imipenem,cefoperazone/sulbactam,amikacin,ciprofloxacin,ticarcillin/clavulanic acid and ceftazidime in proper order.There was a high resistantce to ampicillin,second generation of cephalosporins,cefotaxime and ceftriaxone in GNB.S.aureus had severe drug-resistance to penicillin and oxacillin but was still highly susceptible to vancomycin and teicoplanin.CONCLUSIONS GNB are still the most important pathogens in VAP and have multiple drug-resistance.Mixed infections are severe that should be paid much attentions by clinic.