1846. Effect of Target Vancomycin Trough Concentrations of 15-20 mg/L on Clinical Outcomes in Obese Patients with Suspected Methicillin-Resistant Staphylococcus aureus (MRSA) Pneumonia
Session: Poster Abstract Session: Treatment of HAIs/Antimicrobial Resistant Infections
Saturday, October 10, 2015
Room: Poster Hall
  • IDweek_2015_VAN OUTCOMES-FINAL.pdf (528.6 kB)
  • Background: Vancomycin guidelines recommend maintaining serum trough concentrations between 15-20 mg/L for complicated infections, such as pneumonia.  However clinical data linking treatment outcomes with recommended trough concentrations is limited.  Moreover, despite the increasing burden of obesity, there is no such data in obese patients.

    Methods: We conducted a national retrospective cohort study of obese patients (body mass index ≥ 30) admitted to Veterans Affairs hospitals between 2002 and 2012 with suspected pneumonia (positive MRSA respiratory cultures and clinical signs of infection).  Patients were included if they were initiated on vancomycin treatment and had appropriately collected vancomycin trough levels and no evidence of acute kidney injury prior to vancomycin initiation.  The effect of vancomycin target trough concentrations (15-20 mg/L) compared to non-target troughs (<15 or >20 mg/L) on time to hospital discharge, intensive care unit discharge, 30-day mortality, inpatient mortality, therapy discontinuation, therapy change, 30-day readmission, and 30-day MRSA reinfection was assessed through propensity matching and adjustment of Cox proportional hazards regression models

    Results: We identified 301 patients treated with vancomycin with appropriately collected troughs.  Of those, 21.9% (n=66) had a target trough concentration of 15-20 mg/L and 78.1% (n=235) had a non-target trough concentration.  Patient characteristics were well balanced after implementing propensity score matching (36 matched pairs) and adjustment (within quintiles).  In unadjusted analyses, target trough concentrations of 15-20 mg/L were associated with a lower mortality rate (HR 0.506, 95% CI 0.267- 0.960) than non-target troughs.  However, in adjusted and matched analyses, no significant differences were observed for any of the outcomes assessed.

    Conclusion: In our real-world study of obese patients with suspected MRSA pneumonia, clinical outcomes among those with target trough concentrations of 15-20 mg/L were similar to patients with non-target trough concentrations.

    Haley Morrill, PharmD1,2,3, Aisling Caffrey, PhD, MS1,2,4, Eunsun Noh, PhD, MS1,2 and Kerry Laplante, PharmD1,2,4,5, (1)College of Pharmacy, University of Rhode Island, Kingston, RI, (2)Infectious Diseases Research Program, Providence Veterans Affairs Medical Center, Providence, RI, (3)Providence Veterans Affairs Medical Center, Providence, RI, (4)Center of Innovation in Long-Term Support Services, Providence Veterans Affairs Medical Center, Providence, RI, (5)Warren Alpert Medical School of Brown University, Providence, RI


    H. Morrill, None

    A. Caffrey, Pfizer: Research Support , Grant recipient

    E. Noh, None

    K. Laplante, Cubist Pharmaceuticals: Grant Investigator , Scientific Advisor and Speaker's Bureau , Consulting fee , Grant recipient and Speaker honorarium
    Pfizer Pharmaceuticals: Grant Investigator , Grant recipient
    Theravance Biopharma: Grant Investigator and Scientific Advisor , Consulting fee and Grant recipient
    Durata: Scientific Advisor , Consulting fee
    Forest Laboratories: Scientific Advisor , Consulting fee
    Marvao: Grant Investigator , Grant recipient
    Melinta: Scientific Advisor , Consulting fee
    Davol: Scientific Advisor , Consulting fee
    Theradoc: Scientific Advisor , Consulting fee

    Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 7th with the exception of research findings presented at the IDWeek press conferences.