获得性MRSA肺炎患者死亡率与血清万古霉素水平及MRSA最低抑菌浓度相关性分析

摘要

Objective To investigate the relationship between molecular markers such as the Agr Ⅱ genes, serum vancomycin levels and vancomycin minimum inhibitory concentration ( MIC) , and the 30 - day mortality rate of patients with nosocomial methicillin - resistant Staphylococcus aureus (MRSA) pneumonia in an intensive care unit (ICU). Methods 213 patients with MRSA hospital-acquired pneumonia in ICU of our hospital from 2013 June to 2015 December. The MIC for vancomycin was determined by using the E-test and broth microdilution methods. Variables analyzed included age, sex, comorbid conditions, serum vancomycin trough concentration, the acute physiology and chronic health evaluation Ⅱ ( APACHE Ⅱ) score and the presence of the Agr Ⅱ gene. The primary outcome was mortality at 30 days. Results 90 patients (42. 3%) died within 30 days after MRSA culture. Multiple regression analysis showed that only APACHEⅡscore associated with 30-day mortality ( P=0. 02). E-test results showed that 18 patients with isolates exhibiting an MIC≥1. 5 μg/mL died, 27 patients (12. 7%) survived (P = 0. 74). The broth microdilution results showed that 28 patients (13. 1%) with isolates exhibiting an MIC 1. 0 μg/mL died, 47 patients ( 22. 1%) survived ( P =0. 90). The median APACHE Ⅱ score of survival patients were 22. 7, and the median APACHE Ⅱ score of death patients were 25. 2 (P=0. 02). The presence of the Agr Ⅱ gene was not related to the 30-day mortality rate. Conclusion The hospital-acquired MRSA patients who MIC≤1. 5 μg / mL (E test method) or MIC≤1. 0 μg/mL (the broth microdilution method) had higher 30-day mortality. The APACHE Ⅱ scores which provides an overall estimate of ICU mortality were independently associated with mortality, regardless of the MICs determined. Molecular markers, such as the Agr Ⅱgene, were not associated with higher mortality in the present study.%目的：探讨Agr Ⅱ基因、血清万古霉素水平、万古霉素最低抑菌浓度( MIC)与ICU获得性耐甲氧西林金黄色葡萄球菌( MRSA)肺炎患者30 d内死亡率的相关性。方法研究对象为2013-06~2015-12我院ICU收治的213例获得性MRSA肺炎患者。采用E试验法和微量肉汤稀释法测定患者万古霉素MIC。分析的变量包括年龄、性别、疾病、血清万古霉素谷浓度、急性生理与慢性健康状况评分Ⅱ( APACHEⅡ)和Agr Ⅱ基因。评价指标是患者30 d死亡率。结果90例(42.3%)患者在MRSA培养后30 d内死亡。多元回归结果表明,只有APACHEⅡ评分与患者30 d死亡率相关(P=0.02)。 E试验方法检测结果表明,18例(8.5%)MIC≥1.5μg/mL肺炎患者死亡,27例(12.7%)患者存活(P=0.74)。微量肉汤稀释法检测结果表明,28例(13.1%) MIC为1.0μg/mL患者死亡,47例(22.1%)存活(P=0.90)。生存患者APACHEⅡ评分中位数为22.7,死亡患者APACHEⅡ评分中位数为25.2(P=0.02)。 Agr Ⅱ基因与患者30 d死亡率无关。结论 MIC≤1.5μg/mL(E试验方法)或MIC≤1.0μg/mL(微量肉汤稀释法)的医院获得性MRSA肺炎患者30 d死亡率较高。 APACHEⅡ评分与30 d死亡率独立相关,与MIC无关。 AgrⅡ基因与30 d死亡率无关。