摘要目的 探讨ICU中下呼吸道嗜麦芽窄食单胞菌(SMA)医院内感染的危险因素.方法 对福建省立医院ICU 2007-2010年收治的医院获得性下呼吸道SMA感染的患者进行1:4匹配的病例对照研究,35例下呼吸道SMA感染患者作为病例组,男24例,女11例,年龄34～89岁,平均(76±12)岁,均伴有基础疾病,其中呼吸系统疾病22例,脑血管病和心血管疾病各4例,上消化道出血、胰腺炎、慢性肾脏病、子宫颈癌及阿尔茨海默病各1例.140例无下呼吸道感染的患者作为对照组,男96例,女44例,年龄30～92岁,平均(76±12)岁,均伴有基础疾病,其中心血管疾病44例,呼吸系统疾病30例,脑血管病14例,恶性肿瘤2例,其他疾病50例.分别调查两组患者的基本信息、入住ICU的基本情况、药物使用、诊疗操作及医院感染情况等5个方面.所得数据采用条件logistic回归分析方法进行分析.结果 单因素logistic回归分析结果显示,基础疾病＞4种以上(OR=4.63)、急性生理和慢性健康评分(APACHE-Ⅱ评分)＞20分(OR=10.29)、住ICU前住院时间＞1周(OR=4.34)、使用3种以上抗生素(OR=8.03)或使用碳青霉烯类(OR =3.62)和氨基糖甙类抗生素(OR =4.94)、气管插管(OR =4.10)或气管切开(OR=50.29)、使用机械通气(OR=7.95)为下呼吸道SMA感染的危险因素.多因素logstic回归分析结果显示,APACHE-Ⅱ评分(OR=8.39)、应用抗生素种类(OR=5.96)、气管切开(OR=28.92)为下呼吸道SMA感染的独立危险因素(P值均＜0.01).结论 在ICU中下呼吸道SMA感染的形势严峻,基础疾病、病情、气管造口、机械通气及广谱抗生素的使用可能是SMA感染的重要危险因素；早期识别并防治有助于降低SMA相关性肺炎患者的病死率.

abstractsObjective To explore the risk factors for lower respiratory tract infection by Stenotrophomonas maltophilia in the medical intensive care unit ( MICU ) in Fujian Provincial Hospital.Methods A 1:4 matched case-control study was carried out in the MICU in Fujian Provincial Hospital Thirty-five patients with hospital-acquired lower respiratory tract infection by Stenotrophomonas maltophilia from 2007 to 2010 were included as cases,and 140 patients without lower respiratory tract infection served as controls.The case group included 22 cases with respiratory diseases,4 with cerebrovascular diseases,4 with cardiovascular diseases,1 with hemorrhage of the digestive tract,1 with acute pancreatitis,1 with chronic kidney disease,1 with cervical cancer and 1 with Alzheimer' s disease.While the control group included 30 cases with respiratory diseases,44 with cerebrovascular diseases,14 with cardiovascular diseases,2 with malignant tumors and 50 with others.Patients' information,general situation before being admitted to MICU,drug therapy,invasive procedures and hospital-acquired infection were analyzed.Conditional logistic regression was performed to identify independent risk factors.Results Univariate analysis showed that factors such as more than 4 underlying diseases ( OR =4.63 ),APACHE- Ⅱ score≥20( OR =10.29),stay in the general ward more than 1 week before being admitted to MICU,treatment with more than 3 kinds of antibiotics ( OR =8.03 ),endotracheal intubation ( OR =4.10) or tracheotomy ( OR =50.29 ) and mechanical ventilation (OR =7.95 ) were risk factors for hospital-acquired lower respiratory tract infection by Stenotrophomonas maltophilia.Multivariate logistic regression showed that variables such as APACHE-Ⅱ score ( OR =8.39),kinds of antibiotics used ( OR =5.96 ) and tracheotomy ( OR =28.92 ) were independent risk factors(P ＜ 0.01 ).Conclusions Underlying diseases,the severity of diseases,tracheotomy,mechanical ventilation,and the use of wide-spectrum antibiotics are important risk factors for lower respiratory tract infection by Stenotrophomonas maltophilia in MICU.To identify these factors and take preventive measures earlier may be useful for decreasing Stenotrophomonas maltophilia infection-related mortality.