title: Ventilator-associated pneumonia due to colistin susceptible-only microorganisms.
abstract: Acinetobacter spp. and Pseudomonas aeruginosa are common pathogens of ventilator-associated pneumonia (VAP). The presentation and outcome of VAP due to Acinetobacter spp. and P. aeruginosa susceptible to carbapenems (Carb-S; imipenem and/or meropenem) and to colistin only (Col-S) were compared in the present retrospective study in three intensive care units. A total of 61 episodes of VAP caused by Acinetobacter spp. or P. aeruginosa were studied, of which 30 isolates were Carb-S and 31 were Col-S. Demographics, worsening of renal function and mortality were not different. The univariate analysis showed that a later onset and a previous episode of VAP, prior antimicrobial therapy for >10 days and previous therapy with carbapenems during the present admission were more frequent in patients with Col-S strains. On multivariate analysis, prior antimicrobial therapy for >10 days and a previous episode of VAP remained significantly associated with Col-S VAP. Approximately 41% of the infections caused by Col-S isolates, but none of those due to Carb-S isolates, had received prior carbapenem therapy. Colistin-susceptible ventilator-associated pneumonia episodes can be effectively treated using colistin without significant renal dysfunction. This susceptibility pattern could be suspected in patients with a previous ventilator-associated pneumonia episode or prior antibiotic therapy for >10 days preceding the present ventilator-associated pneumonia episode.
authors.affiliation: Critical Care Service, Profesor Alejandro Posadas Hospital, Haedo, Argentina.
authors.forename: F G
authors.initials: FG
authors.lastname: Rios
authors.forename: C M
authors.initials: CM
authors.lastname: Luna
authors.forename: B
authors.initials: B
authors.lastname: Maskin
authors.forename: A
authors.initials: A
authors.lastname: Saenz Valiente
authors.forename: M
authors.initials: M
authors.lastname: Lloria
authors.forename: S
authors.initials: S
authors.lastname: Gando
authors.forename: C
authors.initials: C
authors.lastname: Sosa
authors.forename: S
authors.initials: S
authors.lastname: Baquero
authors.forename: C
authors.initials: C
authors.lastname: Llerena
authors.forename: C
authors.initials: C
authors.lastname: Petrati
authors.forename: C
authors.initials: C
authors.lastname: Apezteguia
mesh_terms: D000151:Acinetobacter Infections / Q000150:complications / Q000188:drug therapy* / Q000382:microbiology; D000704:Analysis of Variance; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D016009:Chi-Square Distribution; D003091:Colistin / Q000627:therapeutic use*; D004352:Drug Resistance, Microbial; D005260:Female; D006801:Humans; D015378:Imipenem / Q000627:therapeutic use; D008297:Male; D000077731:Meropenem; D008875:Middle Aged; D011014:Pneumonia / Q000188:drug therapy* / Q000209:etiology / Q000382:microbiology*; D011552:Pseudomonas Infections / Q000150:complications / Q000188:drug therapy* / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification; D012121:Respiration, Artificial / Q000009:adverse effects*; D012189:Retrospective Studies; D012307:Risk Factors; D013845:Thienamycins / Q000627:therapeutic use; D012122:Ventilators, Mechanical
chemical_list: D000900:Anti-Bacterial Agents; D013845:Thienamycins; D015378:Imipenem; D000077731:Meropenem; D003091:Colistin