515. Pseudomonas Infections: Do we really need double coverage? A Systematic Review
Session: Poster Session: Hospital-acquired and Transplant Infections
Friday, October 30, 2009: 12:00 AM
Room: Poster Hall A
Background: Treatment for Pseudomonas Aeruginosa infections is challenging due to high mortality rate and the organism’s ability to develop resistance on therapy. Combination therapy has been suggested to overcome resistance but studies have not consistently demonstrated a benefit with combination therapy (except in Cystic Fibrosis) and some have found an increased risk of adverse events.
Objectives: To assess the effects of combination therapy versus monotherapy in hospitalized patients with Pseudomonas infections (excluding Cystic Fibrosis patients).
Methods: We searched Medline (1950-2008), The Cochrane Library (2008, Issue 4), ClinicalTrials.gov (Oct 2008), and relevant studies references for RCTs comparing combination therapy to monotherapy in hospitalized patients with Pseudomonas infection (excluding Cystic Fibrosis). No limits were applied. Two reviewers independently screened studies, extracted data and assessed methodological quality using a standardized form. Disagreements were settled by discussion between the reviewers. Data were pooled using relative risks (RR) calculated with random effects models.
Main results: Nine randomized trials contributed data on 156 patients, only one randomized patients after culture results. Studies included gram negative bacterial infections(4), pneumonia (2), neutropenic fever (2) and serious infections(1) with both immunocompromised patients and imunocompetent hosts. Type of antibiotic used varied widely among studies. No statistically significant difference was found in cure rate (RR 1.12, 95%CI: 0.82-1.54), adverse events (major RR 1.71, 95%CI: 0.19-15.49, minor: RR 1.06, 95%CI 0.59-1.93) or development of resistance on treatment (RR 1.53, 95%CI: 0.73-3.19)
Authors’ conclusion: We found no clear advantage to using combination therapy for pseudomonas infection however our study was significantly limited. Most data was derived from subgroup analysis, many studies had low numbers of patients with pseudomonas and different studies used different antibiotic regimens. More studies, randomizing patients after confirmation of a Pseudomonas infection, are needed.
Sharon alroy-Preis, MD, Dartmouth-Hitchcock Medical Center, Hanover, NH, Nadine McLeod, Ms, The Dartmouth Institute for Health Policy and Clinical Practice, Lebanon, NH and  S. alroy-preis, None..
N. McLeod, None.