重症监护病房血流感染的临床特点和病原学分析

Clinical and microbiological features of nosocomial blood stream infections in intensive care units

目的分析重症监护病房医院获得性血流感染(NBSI)患者的临床特点、流行病学和病原菌对抗菌药物敏感性,为NBSI的预防和经验性用药提供參考。方法回顾整理2010年1月—2013年7月在上海交通大学医学院附属端金医院重症监护病房被诊断为NBSI患者的临床资料和病原学结果并对其进行描述性统计分析。结果共有239例患者发生285例次的NBSI,分离出318株病原微生物,其中复数菌感染者27例。男性158例(66.1%),女性81例(33.9%),平均年龄(62.5±14.8)岁。常见的基础疾病为心血管病83例(34.7%)和肺部感染54例(22.6%)。最常见的诱发因素为留置中心静脉导管212例(88.7%),其次为留置导尿管187例(78.2%),机械通气174例(72.8%)。患者存活114例(47.7%),死亡125例(52.3%),其中以合并鲍曼不动杆菌的复数菌感染者的病死率最高,达85.7%。分离得革兰阳性菌137株(43.1%),革兰阴性菌141株(44.3%),真菌40株(12.6%)。5种最常见的致病菌是凝固酶阴性葡萄球菌68株(21.4%),鲍曼不动杆菌35株(11.0%),屎肠球菌27株(8.5%),肺炎克雷伯菌26株(8.2%)和金黄色葡萄球菌(金葡菌)20株(6.3%)。凝固酶阴性葡萄球菌和金葡菌中甲氧西林耐药菌株占各自菌种的82.4%和75.0%。鲍曼不动杆菌耐药性严重,其对阿米卡星敏感率最高仅为22.9%,其次为头孢哌酮-舒巴坦,敏感率20.0%。肺炎克雷伯菌对阿米卡星、亚胺培南和美罗培南的敏感率分别为73.1%、65.4%和57.7%。白念珠菌为最常见的念珠菌(14株,4.4%),对两性霉素B的敏感率为100%,对伏立康唑、氟康唑和伊曲康唑的敏感率分别为92.9%、85.7%和71.4%。结论重症监护病房NBSI中革兰阴性菌的比率略高于革兰阳性菌,NBSI的病死率高,因此严格的感染控制措施非常重要。

Objective To characterize the feature,prevalence and antimicrobial susceptibility of the pathogens isolated from patients with nosocomial blood stream infections（NBSIs） in intensive care units（ICUs） and provide evidence for prevention and empirical antimicrobial therapy of NBSIs.Methods Clinical and microbiological data were retrospectively collected from the ICU patients with NBSIs in Ruijin Hospital,Shanghai Jiaotong University School of Medicine from January 2010 to July 2013.The data were subjected to descriptive statistical analysis.Results Two hundred and eighty five episodes of NBSIs were identified in 239 patients[158 males,81 females;mean age（62.5±14.8） years].A total of 318 strains were isolated from blood specimens,including multiple microorganisms from 27 patients,The common underlying diseases were cardiovascular disease（83 cases,34.7%） and pulmonary infection（54 cases,22.6%）.Among the potential factors predisposing patients to BSI,central venous catheter was the most frequently identified factor（212 cases,88.7%）,followed by urinary catheter（187 cases,78.2%）,and mechanical ventilation（174 cases,72.8%）.Finally,114patients（47.7%） were cured,while 125 patients（52.3%） died.The highest mortality rate（up to 85.7%） was found in the multipleorganism infection patients with A.baumannii infection.Among the isolates,gram-positive bacteria represented 137（43.1%）,gramnegative bacteria 141（44.3%） and fungus 40（12.6%）.The top five microorganisms were coagulase-negative Staphylococcus（21.4%,68/318）,A.baumannii（11.0%,35/318）,E.faecalis（8.5%,27/318）,K.pneumoniae（8.2%,26/318） and S.aureus（6.3%,20/318）.A.baumannii showed higher resistance rate to the antibiotics tested than other microorganisms.About 73.1%,65.4%and 57.7%of the K.pneumoniae isolates were susceptible to amikacin,imipenem and meropenem,respectively.Candida albicans（4.4%,14/318） was the predominant fungal species.Conclusions Gram-negative bacilli were more prevalent than gram-positive bacteria in the BSIs acquired in ICU.NBSIs showed high mortality.Therefore,strict infection control measures are very important.