Smith Robert L, Evans Heather L, Chong Tae W, McElearney Shannon T, Hedrick Traci L, Swenson Brian R, Scheld W Michael, Pruett Timothy L, Sawyer Robert G
Department of Surgery, University of Virginia, Charlottesville, Virginia 22908-0709, USA.
Surg Infect (Larchmt). 2008 Aug;9(4):423-31. doi: 10.1089/sur.2007.024.
The burden of infection with antibiotic-resistant gram-positive cocci, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE), continues to increase, leading to substantial morbidity and high mortality rates, particularly in intensive care units (ICUs). Creative interventions may be required to reverse or stabilize this trend.
The efficacy of empiric cycling of antibiotics active against gram-positive organisms was tested in a before-after intervention in a single surgical ICU. Four years of baseline data were compared with two years of data compiled after the implementation of a strategy where the empiric antibiotic of choice for the treatment of gram-positive infections (linezolid or vancomycin) was changed every three months. Whatever the initial choice of drug, if possible, the antibiotic was de-escalated after final culture results were obtained. The rates of all gram-positive infections were analyzed, with a particular focus on MRSA and VRE. Concurrently, similar outcomes were followed for patients treated on the same services but outside the ICU, where cycling was not practiced.
During the four years prior to cycling, 543 infections with gram-positive organisms were acquired in the ICU (45.3/1,000 patient-days), including 105 caused by MRSA (8.8/1,000 patient days) and 21 by VRE (1.8/1,000 patient-days). In the two years after implementation of cycling, 169 gram-positive infections were documented (28.1/1,000 patient-days; p < 0.0001 vs. non-cycling period), including 11 caused by MRSA (1.8/1,000 patient-days; p < 0.0001 vs. non-cycling period). The percentage of S. aureus infections caused by MRSA declined from 67% to 36%. The rate of infection with VRE was unchanged. Outside the ICU, the yearly numbers of infections with both MRSA and VRE increased over time.
Quarterly cycling of linezolid and vancomycin in the ICU is a promising method to reduce infections with MRSA.
包括耐甲氧西林金黄色葡萄球菌（MRSA）和耐万古霉素肠球菌（VRE）在内的耐抗生素革兰氏阳性球菌感染负担持续增加，导致严重发病和高死亡率，尤其是在重症监护病房（ICU）。可能需要创新干预措施来扭转或稳定这一趋势。
在单一外科ICU进行前后干预试验，测试针对革兰氏阳性菌的经验性抗生素循环使用的疗效。将四年的基线数据与实施一项策略后收集的两年数据进行比较，该策略为每三个月更换治疗革兰氏阳性感染的经验性首选抗生素（利奈唑胺或万古霉素）。无论最初选择何种药物，如有可能，在获得最终培养结果后降低抗生素级别。分析所有革兰氏阳性感染的发生率，特别关注MRSA和VRE。同时，对在相同科室但不在ICU接受治疗（未进行循环用药）的患者的类似结果进行跟踪。
在循环用药前的四年中，ICU发生了543例革兰氏阳性菌感染（每1000个患者日45.3例），包括105例由MRSA引起（每1000个患者日8.8例）和21例由VRE引起（每1000个患者日1.8例）。在实施循环用药后的两年中，记录了169例革兰氏阳性感染（每1000个患者日28.1例；与非循环用药期相比，p<0.0001），包括11例由MRSA引起（每1000个患者日1.8例；与非循环用药期相比，p<0.0001）。由MRSA引起的金黄色葡萄球菌感染百分比从67%降至36%。VRE感染率未变。在ICU之外，MRSA和VRE的年感染例数随时间增加。
在ICU中每季度循环使用利奈唑胺和万古霉素是一种有前景的减少MRSA感染的方法。
