237. De-escalating Empiric Vancomycin in Patients with Health-Care Associated Pneumonia
Session: Poster Abstract Session: Antimicrobial Stewardship in Clinical Practice
Friday, October 21, 2011
Room: Poster Hall B1
Background: IDSA guidelines recommend de-escalating antibiotics in health-care associated pneumonia (HCAP) based on lower respiratory cultures. In the absence of lower respiratory cultures, physicians are sometimes reluctant to discontinue vancomycin (VANC) that was initiated for suspected HCAP due to methicillin-resistant Staphylococcus aureus (MRSA).  Previous studies have shown that the combination of nasal and throat cultures without growth of MRSA has a negative predictive value of 97% for MRSA colonization. We studied the safety of discontinuing empiric VANC  in HCAP patients (pts) based on negative nasal and throat MRSA surveillance cultures.

Methods: In a convenience sample of pts receiving empiric VANC for suspected MRSA HCAP and in whom no adequate lower respiratory culture was available, the antimicrobial stewardship (AMS) team recommended obtaining nasal and throat swabs, which were inoculated onto chromogenic MRSA selective agar. In pts with both cultures negative for MRSA and a clinical pulmonary infection score (CPIS) less than 6, the AMS team recommended discontinuing VANC.  After discontinuing VANC, charts were retrospectively reviewed to determine if pts expired or developed culture-proven MRSA pneumonia within 30 days.

Results: From a total number of 55 pts, VANC was stopped by day 5 in 43 of these based on nasal and throat swabs negative for MRSA and a low CPIS.  On the day VANC was discontinued in these 43 pts, the CPIS was: 0 (6pts), 1 (10pts), 2 (12pts), 3(10pts), 4(5pts). None of the pts developed confirmed MRSA pneumonia during the rest of their hospital stay, none was readmitted with a MRSA pneumonia, or expired secondary to MRSA pneumonia.  One pt was readmitted with pneumonia of unknown etiology and was treated with piperacillin-tazobactam plus VANC.  One patient who was readmitted for other reasons expired, and an autopsy showed no evidence of pneumonia.

Conclusion: These preliminary data suggest that in the absence of an adequate lower respiratory culture, it is safe to de-escalate empiric VANC in patients who receive VANC to cover for possible MRSA HCAP, and who have both nasal and throat MRSA swab cultures negative and a low CPIS. Further evaluation of this strategy appears warranted.

Subject Category: J. Clinical practice issues

Olivia Fabiola Pop, MD1, Odaliz Abreu-Lanfranco, MD2, Whitney Hung, Pharm D1, Afshin Karjoo, Pharm D1, Ann Fisher, MD1,3 and John Boyce, MD1,3, (1)Hospital of Saint Raphael, New Haven, CT, (2)Division of ID, 5 Hudson, Wayne State University, Detroit Medical Center, Detroit, MI, (3)Yale University School of Medicine, New Haven, CT


O. F. Pop, None

O. Abreu-Lanfranco, None

W. Hung, None

A. Karjoo, None

A. Fisher, None

J. Boyce, None

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.