Abstract：
The methicillin-resistant Staphylococcus aureus (MRSA) polymerase chain reaction (PCR) has a high negative predictive value (NPV). We aimed to understand if there was a difference in the NPV of the MRSA screen in surgical intensive care units (ICUs) and to determine its role in antibiotic de-escalation.
We performed a single-center, retrospective cohort study of adults with a positive respiratory culture and MRSA nasal PCR admitted to a surgical ICU from 2016 to 2019. Patients were stratified by surgical ICU: cardiothoracic/cardiovascular intensive care unit (CVICU) or transplant/acute care surgery intensive care unit (ACS-ICU). Our primary outcome was the NPV of MRSA screen. Secondary outcome was the duration of empiric MRSA-targeted therapy.
We analyzed 61 patients: 42.6% (n = 26) ACS-ICU and 57.4% (n = 35) CVICU. There were no differences in age, comorbidities, prior MRSA infection, recent antibiotic use, immunocompromised status, or renal replacement therapy. At pneumonia diagnosis, more patients in the ACS-ICU were hospitalized ≥5 d (65.4% versus 8.6%, P < 0.0001) and more patients in the CVICU were in septic shock (88.6% versus 34.5%, P < 0.0001) and thrombocytopenic (40% versus 11.5%, P = 0.02). NPV of the PCR was similar (ACS-ICU: 0.92 [0.75-0.98], CV-ICU 0.89 [0.73-0.96]). On multivariable linear regression, the CVICU was associated with longer empiric therapy (β 1.5, 95% CI 0.8-2.3, P < 0.0001), as was hospitalization for ≥5 d (β 0.73, 95% CI 0.06-1.39, P = 0.03).
The MRSA nasal PCR screen has a high NPV for ruling out MRSA pneumonia in critically ill surgical patients. However, patients in the CVICU and patients hospitalized ≥5 d had a longer time to de-escalation of MRSA-targeted therapy, potentially due to higher clinical risk profile.
We performed a single-center, retrospective cohort study of adults with a positive respiratory culture and MRSA nasal PCR admitted to a surgical ICU from 2016 to 2019. Patients were stratified by surgical ICU: cardiothoracic/cardiovascular intensive care unit (CVICU) or transplant/acute care surgery intensive care unit (ACS-ICU). Our primary outcome was the NPV of MRSA screen. Secondary outcome was the duration of empiric MRSA-targeted therapy.
We analyzed 61 patients: 42.6% (n = 26) ACS-ICU and 57.4% (n = 35) CVICU. There were no differences in age, comorbidities, prior MRSA infection, recent antibiotic use, immunocompromised status, or renal replacement therapy. At pneumonia diagnosis, more patients in the ACS-ICU were hospitalized ≥5 d (65.4% versus 8.6%, P < 0.0001) and more patients in the CVICU were in septic shock (88.6% versus 34.5%, P < 0.0001) and thrombocytopenic (40% versus 11.5%, P = 0.02). NPV of the PCR was similar (ACS-ICU: 0.92 [0.75-0.98], CV-ICU 0.89 [0.73-0.96]). On multivariable linear regression, the CVICU was associated with longer empiric therapy (β 1.5, 95% CI 0.8-2.3, P < 0.0001), as was hospitalization for ≥5 d (β 0.73, 95% CI 0.06-1.39, P = 0.03).
The MRSA nasal PCR screen has a high NPV for ruling out MRSA pneumonia in critically ill surgical patients. However, patients in the CVICU and patients hospitalized ≥5 d had a longer time to de-escalation of MRSA-targeted therapy, potentially due to higher clinical risk profile.
摘要：
背景：耐甲氧西林金黄色葡萄球菌（MRSA）聚合酶链反应（PCR）具有很高的阴性预测值（NPV）。我们旨在了解外科重症监护病房（ICU）中MRSA筛查的NPV是否存在差异，并确定其在抗生素降级中的作用。
方法：我们执行了单中心，2016年至2019年入住外科ICU的呼吸道培养和MRSA鼻PCR阳性的成年人的回顾性队列研究.患者按外科ICU进行分层：心胸/心血管重症监护病房（CVICU）或移植/急性护理重症监护病房（ACS-ICU）。我们的主要结果是MRSA筛查的NPV。次要结果是经验性MRSA靶向治疗的持续时间。
结果：我们分析了61例患者：42.6％（n=26）ACS-ICU和57.4％（n=35）CVICU。年龄没有差异,合并症,之前MRSA感染,最近使用抗生素，免疫受损状态，或者肾脏替代疗法.在肺炎诊断时，更多的ACS-ICU患者住院≥5天(65.4%对8.6%，P<0.0001），CVICU中更多的患者发生感染性休克（88.6％对34.5％，P<0.0001)和血小板减少性(40%对11.5%，P=0.02)。PCR的NPV相似（ACS-ICU：0.92[0.75-0.98]，CV-ICU0.89[0.73-0.96]）。关于多元线性回归，CVICU与更长的经验性治疗相关(β1.5,95%CI0.8-2.3,P<0.0001),住院≥5d（β0.73，95%CI0.06-1.39，P=0.03）。
结论：MRSA鼻PCR筛查具有较高的NPV，可排除外科危重患者的MRSA肺炎。然而,CVICU患者和住院≥5d的患者MRSA靶向治疗降阶梯的时间更长，可能是由于临床风险较高。
方法：我们执行了单中心，2016年至2019年入住外科ICU的呼吸道培养和MRSA鼻PCR阳性的成年人的回顾性队列研究.患者按外科ICU进行分层：心胸/心血管重症监护病房（CVICU）或移植/急性护理重症监护病房（ACS-ICU）。我们的主要结果是MRSA筛查的NPV。次要结果是经验性MRSA靶向治疗的持续时间。
结果：我们分析了61例患者：42.6％（n=26）ACS-ICU和57.4％（n=35）CVICU。年龄没有差异,合并症,之前MRSA感染,最近使用抗生素，免疫受损状态，或者肾脏替代疗法.在肺炎诊断时，更多的ACS-ICU患者住院≥5天(65.4%对8.6%，P<0.0001），CVICU中更多的患者发生感染性休克（88.6％对34.5％，P<0.0001)和血小板减少性(40%对11.5%，P=0.02)。PCR的NPV相似（ACS-ICU：0.92[0.75-0.98]，CV-ICU0.89[0.73-0.96]）。关于多元线性回归，CVICU与更长的经验性治疗相关(β1.5,95%CI0.8-2.3,P<0.0001),住院≥5d（β0.73，95%CI0.06-1.39，P=0.03）。
结论：MRSA鼻PCR筛查具有较高的NPV，可排除外科危重患者的MRSA肺炎。然而,CVICU患者和住院≥5d的患者MRSA靶向治疗降阶梯的时间更长，可能是由于临床风险较高。
