院內感染抗藥性葡萄球菌菌血症危險因素之探討

Risk Factors of Nosocomial Oxacillin - Resistant Staphylococci Bacteremia

本研究目的為探討重症病人發生院內感染oxacillin抗藥性葡萄球菌菌血症之危險因子。採回溯性研究法，係以某醫學中心從79年至93年期間所有曾住加護病房發生院內感染葡萄球菌菌血症病人為對象。結果顯示，葡萄球菌菌血症每千人住院平均發生12.5次，以金黃色葡萄菌分離率最高(87%)；對oxacillin具有抗藥性者分別是金黃色葡萄球菌92.3%，凝固酶陰性葡萄球菌96.3。氣管內管(p=.017)和呼吸器使用(p=.003)是發生oxacillin抗藥性葡萄球菌的顯著危險因子；但經Cox迴歸模式發現在控制其他干擾因素後，則肺動脈導管留置是獨立危險因子(Hazard ratio2.05，95%信賴區間1.36-3.08，p＜.001。進行Kaplan-meier分析，估計不同加護病房發生葡萄球菌菌血症前之住院天數，則內科加護病房第21天(95%信賴區間18-24天)、外科加護病房第25天(95%信賴區間18-32天)、內外科綜合加護病房第13天(95%信賴區間11-15天)有一半的病人發生葡萄球菌菌血症感染，經log-rank檢定不同加護病房具有統計上顯著差異(p=.008)。結論：侵入性裝置是引發oxacillin葡萄球菌院內菌血症感染的顯著危險因子，因此落實執行接觸防護措施是預防感染或傳播的重要策略。

This retrospective observational study examined the risk factors of nosocomialoxacillin-resistant Staphylococci bacteremia in adult ICUs. During the researchperiod, the crude infection rate was 12.5 per 1000 patients. Of the Staphylococcibacteremia, Staphylococcus aureus was 87%; of them, oxacillin-resistant Staphylococcusaureus (ORSA) was 92.3% and coagulase-negative Staphylococci was 13%,with oxacillin-resistant 96.3%. After controlling other risk factors for oxacillin-resistantStaphylococci on Cox regression analysis, the Swan-Ganz catheter (odds ratio2.05, 95% confidence interval 1.36-3.08, p<.001) was an independent risk factor.According to the Kaplan-Meier estimator analysis, the median survival time ofhospital stay before the onset of oxacillin-resistant Staphylococci bacteremia was23 days in medical ICU, 25 days in surgical ICU, and on 13 days in mix medicaland surgical ICU, respectively. There was statistically significant difference by logrank test (p<.05). Conclusion: The use of invasive equipment was an important riskfactor in nosocomial staphylococci bacteremia in ICU.