某醫學中心Serratia marcescens中心導管相關血流感染重症患者之死亡預測因子與分離株抗生素敏感性分析

Predictors of mortality and antimicrobial susceptibility among critically ill patients with Serratia marcescens central lineassociated bloodstream infections

過去30年間Serratia marcescens（S. marcescens）已成為常見的醫療照護相關感染致病原之一，伴隨革蘭氏陰性菌分離比率於醫療照護相關感染中逐年增加，而中心導管相關血流感染位居加護病房首要議題，S. marcescens對重症病人之影響不容輕忽。本研究採回溯性研究，分析2011年至2018年6月間，台灣南部某醫學中心成人加護病房S. marcescens中心導管相關血流感染病人之臨床資料、檢驗數據、和分離株之藥物敏感性測試結果。經多變項邏輯斯分析顯示，14天死亡之相關危險因子包括：入住加護病房時診斷為呼吸道疾病（odds ratio（OR）5.58, 95％ confidence interval（CI）1.09～28.03, p＝0.036）、敗血症（OR 6.00, 95％ CI 1.18-30.58, p＝0.031）及Pitt bacteremia score（OR 3.11, 95％ CI 1.17～50.40, p＝0.008），主要且唯一的保護因子為移除中心導管（OR 0.14, 95％ CI 0.02～0.79, p＝0.003）；此外，自確認中心導管血流相關感染發生後，每多留存導管一天，死亡風險則上升2.5倍。而分離菌株的抗生素敏感性測試結果，發現對ceftazidime的感受性僅有70.3％，但對piperacillin／tazobactam（94.6％）、amikacin（97.3％）、gentamicin（91.9％）、ertapenem（97.3％）、imipenem（100.0％）等幾類抗生素，則依舊保有極高的敏感性，可做為經驗性抗生素的選擇。 Globally, central line-associated bloodstream infection (CLABSI) is the leading cause of healthcare-associated infection (HAI). The increasing rate of gram-negative pathogens in HAIs may also have an impact on the outcome of CLABSI. Over the past decade, Serratia marcescens has emerged as a common pathogen in nosocomial infections. Moreover, the therapeutic recommendations for critically ill patients with S. marcescens CLABSI are scarce. This study aimed to identify the risk factors associated with 14th day mortality in patients with S. marcescens CLABSI and antimicrobial susceptibility of the isolates. We retrospectively reviewed medical records of critically ill patients admitted to the adult intensive care unit (ICU) of a medical center in Southern Taiwan from January 2011 to June 2018. Data of 37 patients with monomicrobial S. marcescens CLABSI were included, and 9 (24.3%) had dead within 14 days of onset. In multivariate analysis, main diagnosis at admission to the ICU (respiratory tract diseases [odds ratio {OR} 5.58, 95% confidence interval {CI} 1.09~28.03, p = 0.036), sepsis [OR 6.00, 95% CI 1.18~30.58, p = 0.031]) and a Pitt bacteremia score of > 4 (OR 7.33, 95% CI 1.40~38.34, p = 0.018) were independent risk factors that contributed to 14-day mortality. The single and major protective factor was catheter removal (OR 0.14, 95% CI 0.02~0.79, p = 0.003). Moreover, the mortality risk increased by 2.5-fold per day since the day of CLABSI confirmation in cases of retention of the central line. Relatively lower susceptibility to ceftazidime (70.3%) was observed, and piperacillin/tazobactam, aminoglycoside, or carbapenem were considered suitable empirical drugs.