Orsi G B, Franchi C, Marrone R, Giordano A, Rocco M, Venditti M
Department of Public Health and Infectious Diseases, Sapienza University of Rome, Italy.
Ann Ig. 2012 Jul-Aug;24(4):269-78.
To evaluate laboratory confirmed bloodstream infection (LC-BSI) aetiology we carried out a prospective study in the general 13 bed ICU of the teaching hospital Policlinico Umberto I in Rome. According to CDC case definitions for LC-BSI, all patients admitted >48h between 2000-2007 to ICU were included. Risk factors (i.e. age, sex, SAPS II), invasive procedures (i.e. endotracheal intubation, vascular and urinary catheterisation), microbiological isolates and their antibiotic susceptibility were screened. Overall 1741 patients (64.8% males, 35.2% females) were included, mean age was 58.1 +/- 19.8, SAPS II score 45.1 +/- 17 and ICU stay 14.0 +/- 21.1 days. Finally, 167 (9.6%) patients developed 203 (11.7%) ICU-acquired LC-BSI and sources of infection were CVC (39.8%), unknown (39.3%), respiratory tract (12.4%), surgical wound (6.5%) and urinary tract (2.0%). Between 2000 and 2007 the incidence of LC-BSI/1000 patient days (14.8 per thousands vs. 7.8 per thousands: p<0.05) and LC-BSI/1000 CVC days (20.7 per thousands vs. 11.4 per thousands; p<0.05) decreased. The onset of infection followed ICU admission by 19.5 +/- 17.7 (mean) and 13 days (median). Crude mortality was 34.8%, and mortality associated with LC-BSI showed a RR 1.61; 95%CI 1.37 - 1.89; p<0.01. The most common pathogens were coagulase negative staphylococci (CNS) (26.2%), methicillin-resistant Staphylococcus aureus (MRSA) (14.9%), Pseudomonas aeruginosa (13.5%), enterococci (9.3%) and Acinetobacter bawnumannii (7.5%). Onset time (days) between ICU admission and LC-BSI was higher (p<0.01) among Gram-negative (22.9 +/- 18.4) compared to Gram-positive (16.6 +/- 15.9), fungi (23.8 +/- 25.3). High early death (<7 days after BSI diagnosis) was associated to A. baumannii (37.5%), Candida spp. (30.0%) and S. aureus (29.7%). Staphylococci presented a very high methicillin resistance (>85%). P. aeruginosa and A. baumannii showed respectively 25% and 68.7% multidrug-resistance. Over 1/3 of Eneterobacteriaceae isolates were extended spectrum beta-lactamase (ESBL), but non resulted resistant to carbapenems. Surveillance showed a high incidence of LC-BSI associated to invasive procedures and the presence of multiresistant bacteria.
为评估实验室确诊的血流感染（LC-BSI）病因，我们在罗马的翁贝托一世综合医院拥有13张床位的普通重症监护病房（ICU）开展了一项前瞻性研究。根据美国疾病控制与预防中心（CDC）关于LC-BSI的病例定义，纳入了2000年至2007年间入住ICU超过48小时的所有患者。筛查了危险因素（即年龄、性别、简化急性生理学评分II [SAPS II]）、侵入性操作（即气管插管、血管和导尿管插入术）、微生物分离株及其抗生素敏感性。共纳入1741例患者（男性占64.8%，女性占35.2%），平均年龄为58.1±19.8岁，SAPS II评分为45.1±17，ICU住院时间为14.0±21.1天。最终，167例（9.6%）患者发生了203例（11.7%）ICU获得性LC-BSI，感染源为中心静脉导管（CVC）（39.8%）、不明（39.3%）、呼吸道（12.4%）、手术伤口（6.5%）和泌尿道（2.0%）。2000年至2007年间，每1000患者日的LC-BSI发病率（14.8‰对7.8‰：p<0.05）和每1000 CVC日的LC-BSI发病率（20.7‰对11.4‰；p<0.05）有所下降。感染发生在入住ICU后19.5±17.7天（均值）和13天（中位数）。粗死亡率为34.8%，与LC-BSI相关的死亡率显示相对危险度（RR）为1.61；95%置信区间（CI）为1.37 - 1.89；p<0.01。最常见的病原体为凝固酶阴性葡萄球菌（CNS）（26.2%）、耐甲氧西林金黄色葡萄球菌（MRSA）（14.9%）、铜绿假单胞菌（13.5%）、肠球菌（9.3%）和鲍曼不动杆菌（7.5%）。与革兰氏阳性菌（16.6±15.9天）和真菌（23.8±25.3天）相比，革兰氏阴性菌（22.9±18.4天）在入住ICU至LC-BSI的发病时间（天数）更高（p<0.01）。早期高死亡率（BSI诊断后<7天）与鲍曼不动杆菌（37.5%）、念珠菌属（30.0%）和金黄色葡萄球菌（29.7%）相关。葡萄球菌呈现出非常高的耐甲氧西林率（>85%）。铜绿假单胞菌和鲍曼不动杆菌分别显示25%和68.7%的多重耐药率。超过1/3的肠杆菌科分离株为超广谱β-内酰胺酶（ESBL），但对碳青霉烯类均无耐药。监测显示与侵入性操作和多重耐药菌的存在相关的LC-BSI发病率较高。
