Soriano Alex, Marco Francesc, Martínez José A, Pisos Elena, Almela Manel, Dimova Veselka P, Alamo Dolores, Ortega Mar, Lopez Josefina, Mensa Josep
Department of Infectious Diseases, Hospital Clinic of Barcelona, Barcelona, Spain.
Clin Infect Dis. 2008 Jan 15;46(2):193-200. doi: 10.1086/524667.
Vancomycin treatment failure in methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is not uncommon, even when MRSA is susceptible to vancomycin. The aim of our study was to evaluate whether vancomycin minimum inhibitory concentration has any influence on the mortality associated with MRSA bacteremia.
A total of 414 episodes of MRSA bacteremia were prospectively followed-up from 1991 through 2005. MIC of vancomycin for the first isolate was determined by E-test. Clinical variables recorded were age, comorbidity, prior administration of vancomycin, use of corticosteroids, prognosis of underlying disease, source of bacteremia, the need for mechanical ventilation, shock, and mortality. A "treatment group" variable was created and defined as follows: (1) receipt of empirical vancomycin and an isolate with a vancomycin MIC of 1 microg/mL (38 episodes), (2) receipt of empirical vancomycin and an isolate with a vancomycin MIC of 1.5 microg/mL (90 episodes), (3) receipt of empirical vancomycin and an isolate with a vancomycin MIC of 2 microg/mL (40 episodes), and (4) receipt of inappropriate empirical therapy (246 episodes). Univariate and multivariate analyses were performed.
Episodes caused by strains with a vancomycin MIC of 2 microg/mL were independently associated with a lower risk of shock (odds ratio [OR], 0.33; 95% confidence interval [CI], 0.15-0.75). Multivariate analysis selected receipt of empirical vancomycin and an isolate with a vancomycin MIC of 2 microg/mL (OR, 6.39; 95% CI, 1.68-24.3), receipt of inappropriate empirical therapy (OR, 3.62; 95% CI, 1.20-10.9), increasing age (OR, 1.02; 95% CI, 1.00-1.04), use of corticosteroids (OR, 1.85; 95% CI, 1.04-3.29), an ultimately (OR, 10.2; 95% CI, 2.85-36.8) or rapidly (OR, 1.81; 95% CI, 1.06-3.10) fatal underlying disease, high-risk (OR, 3.60; 95% CI, 1.89-6.88) and intermediate-risk (OR, 2.18; 95% CI, 1.17-4.04) sources of bacteremia, and shock (OR, 7.38; 95% CI, 4.11-13.3) as the best predictors of mortality.
Mortality associated with MRSA bacteremia was significantly higher when the empirical antibiotic was inappropriate and when vancomycin was empirically used for treatment of infection with strains with a high vancomycin MIC (>1 microg/mL).
耐甲氧西林金黄色葡萄球菌（MRSA）菌血症中万古霉素治疗失败并不罕见，即便MRSA对万古霉素敏感。我们研究的目的是评估万古霉素最低抑菌浓度是否对与MRSA菌血症相关的死亡率有任何影响。
从1991年至2005年对总共414例MRSA菌血症发作进行前瞻性随访。通过E试验测定首个分离株的万古霉素MIC。记录的临床变量包括年龄、合并症、既往万古霉素使用情况、皮质类固醇的使用、基础疾病的预后、菌血症来源、机械通气需求、休克和死亡率。创建并定义了一个“治疗组”变量，如下：（1）接受经验性万古霉素治疗且分离株万古霉素MIC为1微克/毫升（38例发作），（2）接受经验性万古霉素治疗且分离株万古霉素MIC为1.5微克/毫升（90例发作），（3）接受经验性万古霉素治疗且分离株万古霉素MIC为2微克/毫升（40例发作），以及（4）接受不适当的经验性治疗（246例发作）。进行了单变量和多变量分析。
由万古霉素MIC为2微克/毫升的菌株引起的发作与较低的休克风险独立相关（比值比[OR]，0.33；95%置信区间[CI]，0.15 - 0.75）。多变量分析选择接受经验性万古霉素治疗且分离株万古霉素MIC为2微克/毫升（OR，6.39；95% CI，1.68 - 24.3）、接受不适当的经验性治疗（OR，3.62；95% CI，1.20 - 10.9）、年龄增加（OR，1.02；95% CI，1.00 - 1.04）、皮质类固醇的使用（OR，1.
