Maclayton Darego O, Suda Katie J, Coval Krista A, York Cynthia B, Garey Kevin W
Texas Southern University College of Pharmacy & Health Sciences, Houston, Texas, USA.
University of Tennessee College of Pharmacy, Memphis, Tennessee, USA.
Clin Ther. 2006 Aug;28(8):1208-1216. doi: 10.1016/j.clinthera.2006.08.003.
An increased prevalence of bacteremia caused by methicillin-resistant Staphylococcus aureus (MRSA) with a vancomycin hydrochloride MIC of 2 microg/mL was noted in a population of inpatients undergoing hemodialysis at Baptist Memorial Health Care, Memphis, Tennessee.
The aims of this study were to determine risk factors for infection with MRSA and to assess the differences in clinical and economic outcomes in patients undergoing hemodialysis with MRSA bacteremia with vancomycin MIC 2 microg/mL versus those with MRSA bacteremia with vancomycin MIC < or =0.5 microg/mL and uninfected controls.
This retrospective case-control study was conducted at Baptist Memorial Health Care. The study population (inpatients undergoing hemodialysis for MRSA bacteremia with vancomycin MIC 2 microg/mL [high-MIC group], MIC < or = 0.5 microg/mL [low-MIC group], and uninfected controls) was identified. Risk factors and clinical and economic outcomes (costs of hospitalization, nursing, and pharmacy) were determined and compared using univariate and multivariate statistics.
Fifty patients with MRSA bacteremia undergoing hemodialysis were identified during the study period (high-MIC group, 17 [11 women, 6 men; mean (SD) age, 60 (17) years]; low-MIC group, 33 [23 women, 10 men; mean (SD) age, 62 (14) years]) and matched with 100 uninfected controls (57 men, 43 women; mean [SD] age, 63 [15] years). Risk factors for MRSA bacteremia found to be associated with high MIC included female sex, higher body mass index (1-point increments), recent surgery, and a history of cardiovascular disease (P < 0.05, P < 0.046, P = 0.04, and P = 0.028, respectively) (multivariate analysis). In the outcomes analysis, mortality was significantly higher in the high-MIC group compared with those in the low-MIC and control groups (35% vs 24% and 15%, respectively; P = 0.022). Total mean (SD) hospitalization costs were significantly higher in the high-MIC group compared with those in the low-MIC group and controls (US $47,624 [$80,534] vs $26,792 [$25,167] and $13,185 [$15,568], respectively; P < 0.001). Nursing costs were almost 6-fold higher in both infected groups compared with those in controls. Pharmacy costs in the low- and high-MIC groups were 3- to 6-fold higher, respectively, compared with those in controls.
Surgery within the previous 6 months and intensive care unit admission were identified as significant risk factors for patients with MRSA bacteremia with a vancomycin MIC 2 microg/mL undergoing hemodialysis. These patients experienced a longer mean hospital length of stay and increased hospital costs compared with patients with MRSA bacteremia with a vancomycin MIC < or =0.5 microg/mL and uninfected controls.
在田纳西州孟菲斯市浸信会纪念医疗中心接受血液透析的住院患者群体中，发现耐甲氧西林金黄色葡萄球菌（MRSA）引起的菌血症患病率有所增加，且这些MRSA对盐酸万古霉素的最低抑菌浓度（MIC）为2微克/毫升。
本研究旨在确定MRSA感染的危险因素，并评估万古霉素MIC为2微克/毫升的MRSA菌血症血液透析患者与万古霉素MIC≤0.5微克/毫升的MRSA菌血症患者及未感染对照组在临床和经济结局方面的差异。
本回顾性病例对照研究在浸信会纪念医疗中心开展。确定了研究人群（因MRSA菌血症接受血液透析的住院患者，万古霉素MIC为2微克/毫升[高MIC组]、MIC≤0.5微克/毫升[低MIC组]以及未感染对照组）。使用单变量和多变量统计方法确定并比较危险因素以及临床和经济结局（住院、护理和药房费用）。
在研究期间确定了50例接受血液透析的MRSA菌血症患者（高MIC组17例[11名女性，6名男性；平均（标准差）年龄60（17）岁]；低MIC组33例[23名女性，10名男性；平均（标准差）年龄62（14）岁]），并与100例未感染对照（57名男性，43名女性；平均[标准差]年龄63（15）岁）进行匹配。发现与高MIC相关的MRSA菌血症危险因素包括女性、较高的体重指数（每增加1个单位）、近期手术以及心血管疾病史（分别为P<0.05、P<0.046、P = 0.04和P = 0.028）（多变量分析）。在结局分析中，高MIC组的死亡率显著高于低MIC组和对照组（分别为35%、24%和15%；P = 0.022）。高MIC组的总平均（标准差）住院费用显著高于低MIC组和对照组（分别为47,624美元[80,534美元]、26,792美元[25,167美元]和13,185美元[15,568美元]；P<0.001）。两个感染组的护理费用几乎是对照组的6倍。低MIC组和高MIC组的药房费用分别是对照组的3至6倍。
既往6个月内的手术和入住重症监护病房被确定为接受血液透析且万古霉素MIC为2微克/毫升的MRSA菌血症患者的重要危险因素。与万古霉素MIC≤0.5微克/毫升的MRSA菌血症患者及未感染对照组相比，这些患者的平均住院时间更长，住院费用更高。
