泛耐药鲍曼不动杆菌菌血症危险因素及临床结局

目的　比较泛耐药鲍曼不动杆菌（pan-drug resistant Acinetobacter baumannii，PDRAB）菌血症与非泛耐药鲍曼不动杆菌（non-pan-drug resistant Acinetobacter baumannii，NPDRAB）菌血症的临床资料，探讨PDRAB菌血症的危险因素及其临床结局。方法　本研究为回顾性队列研究，纳入对象为2010年1月1日至2012年12月31日就诊于北京协和医院的鲍曼不动杆菌菌血症患者，采用统一的标准表格收集患者的临床资料和检验结果，以鲍曼不动杆菌血培养标本采集14 d内发生院内死亡为主要临床结局。 结果　共纳入52例鲍曼不动杆菌菌血症患者，平均年龄（54±20）岁，其中男性30例（57.7%）；平均急性生理与慢性健康状况Ⅱ（acute physiology and chronic health evaluation Ⅱ, APACHE Ⅱ）评分（21±9）分，平均序贯器官衰竭评估（sepsis-related organ failure assessment，SOFA）评分（10±5）分；鲍曼不动杆菌菌血症发生前，患者中位住院时间为12 d（7～20 d）；仅6例患者对碳青霉烯类药物敏感。33例患者感染NPDRAB，19 例感染PDRAB。在感染鲍曼不动杆菌前，PDRAB患者与NPDRAB患者比较，接受机械通气概率更大（94.7%比63.6%，P=0.031），住院时间更长（中位住院时间17 d比10 d，P=0.025）。鲍曼不动杆菌菌血症患者14 d死亡率为67.3%（35/52）。多因素分析提示，脓毒性急性肾损伤（OR 7.9，95% CI 1.113～55.448，P=0.039）、不适当抗菌药物治疗（OR 9.4，95% CI 1.020～87.334，P=0.048）和降钙素原水平（OR 1.3，95% CI 1.332～1.088，P=0.005）是鲍曼不动杆菌菌血症患者14 d死亡的独立危险因素。结论　鲍曼不动杆菌具有多重耐药性，甚至对目前所有全身用抗菌药物均不敏感，感染患者死亡率较高。菌血症发生前接受机械通气和住院时间是PDRAB 菌血症的危险因素，但PDRAB感染本身不能作为判断患者预后不良的指标。不适当抗菌药物治疗、脓毒性急性肾损伤和降钙素原水平是鲍曼不动杆菌菌血症患者14 d死亡的独立危险因素。

Risk Factors and Clinical Outcomes of Pan-drug Resistant Acinetobacter baumannii Bacteremia

Objective　To determine the risk factors and outcomes of pan-drug resistant Acinetobacter baumannii(PDRAB) bacteremia by comparing clinical data of PDRAB patients with those of non-pan-drug resistant Acinetobacter baumannii (NPDRAB) bacteremia. Methods　This retrospective cohort study included patients with Acinetobacter baumannii bacteremia diagnosed and treated in Peking Union Medical College Hospital during January 1, 2010 and December 31, 2012. Clinical data and laboratory test results of the patients were collected with unified forms. The primary clinical outcome was in-hospital death within 14 days after sample collection for blood culture of Acinetobacter baumannii.Results　A total of 52 patients with Acinetobacter baumannii bacteremia were included, with the mean age of 54±20 years and including 30 (57.7%) males. The mean acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score and sepsis-related organ failure assessment (SOFA) score were 21±9 and 10±5, respectively. The median length of hospital stay before Acinetobacter baumannii bacteremia was 12 days (7-20 days). Among these patients, only 6 cases were sensitive to carbapenem. Thirty-three cases were infected by NPDRAB and 19 by PDRAB. Compared with NPDRAB patients, PDRAB patients had a higher rate of receiving mechanical ventilation (94.7% vs. 63.6%, P=0.031) and a longer hospital stay (median: 17 days vs. 10 days, P=0.025) before Acinetobacter baumannii infection. The 14-day mortality rate in patients with Acinetobacter baumannii bacteremia was 67.3% (35/52). In multivariate analysis, septic acute kidney injury［odds ratio (OR) 7.9, 95% confidence interval (CI) 1.113-55.448, P=0.039］, inappropriate anti-microbial therapy (OR 9.4, 95% CI 1.020-87.334, P=0.048), and procalcitonin level (OR 1.3, 95% CI 1.332-1.088, P=0.005) were independent risk factors of 14-day mortality in Acinetobacter baumannii bacteremia patients. Conclusions　Acinetobacter baumannii has multi-drug resistance and is even not susceptible to all currently available systemic antimicrobials. Acinetobacter baumannii infection is associated with high mortality rate. Mechanical ventilation and long hospital stay before occurrence of bacteremia are risk factors for PDRAB bacteremia. However, PDRAB infection itself is not a predictor of poor prognosis. Inappropriate antimicrobial therapy, septic acute kidney injury, and procalcitonin level are independent risk factors of 14-day mortality in Acinetobacter baumannii bacteremia.