October 2013, Vol 144, No. 4_MeetingAbstracts Critical Care | October 2013
Can the Nasal MRSA PCR Be Used to Shorten Empiric MRSA Antibiotic Therapy in Severe Sepsis and Septic Shock? Shant Shirvanian, MD; Jeffrey Fried, MD; Jonathan Grotts, MA Santa Barbara Cottage Hospital, Santa Barbara, CA Chest. 2013;144(4_MeetingAbstracts):412A. doi:10.1378/chest.1703390
Abstract SESSION TITLE: Sepsis and Septic Shock SESSION TYPE: Original Investigation Slide PRESENTED ON: Monday, October 28, 2013 at 07:30 AM - 09:00 AM PURPOSE: To evaluate the nasal methicillin resistant staphylococcus aureus (MRSA) polymerase chain reaction (PCR) as a screening tool for MRSA infections in patients admitted to the adult Intensive Care Unit (ICU) with severe sepsis or septic shock. METHODS: We performed a retrospective study at a community teaching hospital by identifying patients from the IRB approved Santa Barbara Cottage Hospital Sepsis Registry, a prospectively collected database of all patients admitted to our adult ICUs with severe sepsis and septic shock. Patients were admitted to the ICU from January 2009 - March 2012, who had nasal MRSA PCR (nPCR) and bacterial cultures collected within 24 hours of presentation. RESULTS: We evaluated 988 patients. 191 were excluded due to incomplete data (181 did not have nPCR performed within 24 hours and 10 patients had unresolved nPCR results). The remaining 797 patients were included and had a total of 2,491 bacterial cultures from other sites. Out of 698 patients with a negative nPCR, 10 (1.4%) had positive MRSA cultures, which were all clinically significant (3 had a positive blood culture, 4 had a positive wound culture, 2 had a positive urine culture and 1 patient had a positive respiratory culture). Of 99 patients with a positive nPCR, 37 (37.4%) had positive MRSA cultures at non-nasal sites. The nPCR performed with a sensitivity of 79%, specificity of 92%, positive predictive value of 37%, negative predictive value of 99% and an accuracy of 91%. The mean time difference between the nPCR result and bacterial culture results from other sites positive for MRSA was 2.7 days. CONCLUSIONS: Given its high negative predictive value, the nasal MRSA PCR may serve as a screening tool for MRSA in patients admitted to the ICU with severe sepsis and septic shock. CLINICAL IMPLICATIONS: In patients admitted to ICUs with severe sepsis or septic shock, a negative nasal MRSA PCR could guide therapy to shorten the duration of empiric antibiotics targeted at MRSA by as much as 2.7 days.
DISCLOSURE: The following authors have nothing to disclose: Shant Shirvanian, Jeffrey Fried, Jonathan Grotts No Product/Research Disclosure Information