Silvestri L, Monti Bragadin C, Milanese M, Gregori D, Consales C, Gullo A, van Saene H K
Department of Anaesthesia and Intensive Care, University of Trieste, Italy.
J Hosp Infect. 1999 Jun;42(2):125-33. doi: 10.1053/jhin.1998.0550.
A prospective cohort study was undertaken with two end points: (i) to compare the 48 h time cut-off with the carrier state criterion for classifying infections, and (ii) to determine a time cut-off more in line with the carrier state concept. All patients admitted to the intensive care unit and expected to require mechanical ventilation for a period > or = 3 days were enrolled. Surveillance cultures of throat and rectum were obtained on admission and thereafter twice weekly to distinguish micro-organisms that were imported into the intensive care unit from those acquired during the stay in the unit. A total of 117 patients with median age of 61 years and median Simplified Acute Physiology Score II of 42, were included in the study. Of these patients, 48 (41%) developed a total of 74 infection episodes. Using the 48 h cut-off point, 80% of all infections were classified as ICU-acquired. According to the carrier state criterion, 44 infections (60%) were of primary endogenous development caused by micro-organisms imported into the intensive care unit. Seventeen secondary endogenous (23%) and 13 exogenous (17%) infections were caused by bacteria acquired in the unit. The carrier state classification allowed the transfer of 49% of infections from the ICU-acquired group into the import group. A time cut-off of nine days was found to identify ICU-acquired infections better than two days. These data suggest that monitoring of carriage of micro-organisms may be a more realistic approach to classify infections developing in the intensive care unit.
进行了一项前瞻性队列研究，有两个终点：（i）比较将感染分类的48小时时间界限与带菌状态标准；（ii）确定一个更符合带菌状态概念的时间界限。纳入所有入住重症监护病房且预计需要机械通气≥3天的患者。入院时以及之后每周两次采集咽喉和直肠的监测培养物，以区分进入重症监护病房时携带的微生物与住院期间获得的微生物。共有117例患者纳入研究，年龄中位数为61岁，简化急性生理学评分II中位数为42。其中48例（41%）共发生74次感染发作。采用48小时界限时，所有感染的80%被分类为重症监护病房获得性感染。根据带菌状态标准，44例感染（60%）是由进入重症监护病房时携带的微生物引起的原发性内源性感染。17例继发性内源性感染（23%）和13例外源性感染（17%）是由在病房获得的细菌引起的。带菌状态分类使49%的感染从重症监护病房获得性感染组转入带入性感染组。发现9天的时间界限比2天能更好地识别重症监护病房获得性感染。这些数据表明，监测微生物携带情况可能是对重症监护病房发生的感染进行分类的一种更实际的方法。
