title: Treatment of Carbapenem-Resistant Acinetobacter baumannii Ventilator-Associated Pneumonia: Retrospective Comparison Between Intravenous Colistin and Intravenous Ampicillin-Sulbactam.
abstract: Carbapenem-resistant Acinetobacter baumannii has been increasingly reported as the causative agent of ventilator-associated pneumonia (VAP) among patients in the intensive care units. However, there are insufficient data to guide the appropriate treatment for such infection. Our aim was to compare the outcome of carbapenem-resistant A. baumannii VAP treated with colistin or with ampicillin-sulbactam. We conducted a retrospective study of patients diagnosed with carbapenem-resistant A. baumannii VAP during 2008 and 2009. Clinical and microbiologic cure rates, 30-day mortality, and change in renal function were compared between patients treated with colistin versus those treated with ampicillin-sulbactam. The association between treatment and mortality was examined through multivariable logistic regression analysis. Of the 98 patients diagnosed with carbapenem-resistant A. baumannii VAP, 66 were treated with colistin and 32 with ampicillin-sulbactam. Baseline characteristics of patients were similar, except for a longer intensive care unit stay and lower creatinine clearance test before VAP diagnosis among patients treated with colistin. Clinical cure rates were similar in the 2 groups. In the colistin group, microbiologic failure rates were higher at 7 days [16/33 (48%) vs. 3/17 (18%); P = 0.03]; patients had a more significant elevation in creatinine (+0.2 ± 1.0 mg/dL vs. -0.3 ± 1.1 mg/dL; P = 0.021), and treatment was associated with an increased 30-day mortality (adjusted-odds ratio, 6.5; 95% confidence interval, 1.348-31.342; P = 0.02). In conclusion, patients treated with colistin or ampicillin-sulbactam had similar clinical cure rates. However, colistin was associated with higher rates of microbiologic failure, reduction in renal function, and an increased 30-day mortality. A prospective study comparing high-dose colistin and ampicillin-sulbactam for the treatment of carbapenem-resistant A. baumannii VAP is warranted.
authors.affiliation: 1Department of Internal Medicine C, Rambam Health Care Campus, Haifa, Israel; 2Unit of Infectious Diseases, Rambam Health Care Campus, Haifa, Israel; 3Departments of Internal Medicine B and 4Internal Medicine A, Rambam Health Care Campus, Haifa, Israel; and 5Microbiology Laboratory, Rambam Health Care Campus, Haifa, Israel.
authors.forename: Ronen
authors.initials: R
authors.lastname: Zalts
authors.forename: Ami
authors.initials: A
authors.lastname: Neuberger
authors.forename: Khetam
authors.initials: K
authors.lastname: Hussein
authors.forename: Ayelet
authors.initials: A
authors.lastname: Raz-Pasteur
authors.forename: Yuval
authors.initials: Y
authors.lastname: Geffen
authors.forename: Tanya
authors.initials: T
authors.lastname: Mashiach
authors.forename: Renato
authors.initials: R
authors.lastname: Finkelstein
mesh_terms: D040981:Acinetobacter baumannii / Q000187:drug effects*; D061605:Administration, Intravenous; D000328:Adult; D000368:Aged; D000667:Ampicillin / Q000008:administration & dosage / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D015780:Carbapenems / Q000494:pharmacology*; D003091:Colistin / Q000008:administration & dosage / Q000627:therapeutic use*; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D053717:Pneumonia, Ventilator-Associated / Q000188:drug therapy* / Q000401:mortality; D012189:Retrospective Studies; D013407:Sulbactam / Q000008:administration & dosage / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; C035444:sultamicillin; D000667:Ampicillin; D013407:Sulbactam; D003091:Colistin