呼吸重症监护病房鲍曼不动杆菌下呼吸道感染的临床特征及影响因素初步分析

Clinical characteristics and influencing factors of lower respiratory tract infection of Acinetobacter baumannii in respiratory intensive care unit

目的回顾性分析呼吸重症监护病房(RICU)的鲍曼不动杆菌下呼吸道感染(AB-LRTI)流行特征,为防治RICU的AB-LRTI提供临床依据。方法收集苏州大学附属第一医院RICU的204例细菌学为鲍曼不动杆菌(AB)的患者临床资料。细菌学标本源自痰液、支气管镜气管内吸出物、支气管肺泡灌洗液、胸腔积液及血液。AB定植据美国CDC/NHSN定义判定。40例仅分离出AB经判断为AB定植组;63例仅分离出AB经判断为感染作为单纯AB-LRTI组;101例同时分离出AB及另一种病原体经判断为混合LRTI,作为合并其他菌LRTI组。比较各组流行病学、临床特征及影响因素。结果与AB定植组相比,合并其他菌LRTI组中的免疫抑制者、标本源于痰和灌洗液的比例、≥4项侵入性操作、90天病死率均高于定植组;白细胞计数>10×10^(9)/L(或<4×10^(9)/L)、中性粒细胞百分比>75%(或<40%)、淋巴细胞计数<1.1×10^(9)/L、血小板计数<100×10^(9)/L、白蛋白<30 g/L、高敏C反应蛋白>10 mg/L的患者比例以及中性粒细胞/淋巴细胞计数比值(NLR)均较高,差异有统计学意义(均P<0.05);合并其他菌LRTI组中首次分离出AB前90天内行支气管镜治疗次数及碳青霉烯类使用时间天数、急性生理学和慢性健康状况评分系统Ⅱ评分、行有创机械通气、有创机械通气天数患者均多于定植组,差异有统计学意义(均P<0.05)。合并其他菌LRTI组首次分离出AB前90天内使用碳青霉烯类及β-内酰胺类/β-内酰胺酶抑制剂的时间、并发感染性休克、NLR、90天病死率均多于单纯AB-LRTI组,差异有统计学意义(均P<0.05)。经回归分析,≥4项侵入性操作、有免疫抑制、首次分离出AB前90天内使用碳青酶烯类时间长均为AB-LRTI的独立危险因素。结论RICU患者的单纯AB-LRTI与AB合并其他菌LRTI之间,以及与AB定植之间,流行病学、临床症状及实验室指标存在明显差异,≥4项侵入性操作、有免疫抑制、首次分离出AB前90天内使用碳青酶烯类时间长的RICU患者更易发生AB-LRTI。

Objective To investigate clinical characteristics and influencing factors of lower respiratory tract infection of Acinetobacter baumannii(AB-LRTI)in respiratory intensive care unit(RICU).Methods Clinical data were collected from 204 RICU patients who were isolated Acinetobacter baumannii(AB).The bacteriological specimens were derived from sputum,bronchoscopic endotracheal aspiration,bronchoalveolar lavage fluid,pleural effusion and blood.The definition of bacterial colonization was based on the responsible criteria from Centers for Disease Control and Prevention/National Medical Safety Network(CDC/NHSN).The patients were divided into three groups as follows,AB colonization group(only AB was isolated,n=40);simple AB-LRTI group(only AB was isolated and defined as infection,n=63),AB with another bacteria LRTI group(AB and another pathogen were isolated simultaneously,n=101).The epidemiology,clinical characteristics and influencing factors of each group were analyzed and compared.Results Compared with the AB colonization group,the AB with another bacteria LRTI group had higher proportion of patients with immunosuppression,specimens from sputum and bronchoalveolar lavage fluid,more than 4 invasive procedures,90-day mortality,white blood cell count>10×10^(9)/L(or<4×10^(9)/L),neutrophil percent>75%(or<40%),lymphocyte count<1.1×10^(9)/L,platelet count<100×10^(9)/L,albumin<30 g/L,high sensitivity C-reactive protein>10 mg/L,and neutrophil-to-lymphocyte ratio(NLR).The frequency of bronchoscopy and days of infusing carbapenem within 90 days before isolating AB,the Acute Physiology and Chronic Health EvaluationⅡscore,the proportion of patients with invasive mechanical ventilation and the duration of invasive mechanical ventilation in the AB with another pathogen LRTI group were higher than those in the AB colonization group(all P<0.05).Days of infusing carbapenem andβ-lactams/β-lactamase inhibitors within 90 days before isolating AB,proportion of septic shock,NLR and 90-day mortality of the patients from the AB with another pathogen LRTI group were more than those in the simple AB-LRTI group(all P<0.05).After regression analysis,more than 4 invasive procedures,or immunosuppression,or with more days of infusing carbapenem within 90 days before isolating AB were all the independent risk factors for AB-LRTI.Conclusions There are significant differences in epidemiology,clinical symptoms and laboratory indicators between simple AB-LRTI,AB with another pathogen LRTI and AB colonization in RICU patients.For RICU patients,who suffered more than 4 invasive procedures,immunosuppression,or with more days of infusing carbapenem within 90 days before isolating AB,are more susceptible to AB-LRTI.