JAC Advance Access originally published online on March 25, 2008
Journal of Antimicrobial Chemotherapy 2008 61(6):1369-1375; doi:10.1093/jac/dkn128
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Original research |
Ampicillin/sulbactam compared with polymyxins for the treatment of infections caused by carbapenem-resistant Acinetobacter spp.
1 Department of Infection Control of Hospital das Clínicas, Rua Dr Ovídio Pires de Campos, 225, Sala 629, São Paulo-SP 05403-010, Brazil 2 Department of Infectious Diseases and LIM-54, University of São Paulo, Av. Dr Enéas de Carvalho Aguiar, 470, São Paulo-SP 05403-000, Brazil 3 Department of Infection Control of Hospital do Servidor Público Estadual de São Paulo, Avenida Ibirapuera, 981, São Paulo-SP 04029-000, Brazil
Received 7 December 2007; returned 28 December 2007; revised 26 February 2008; accepted 28 February 2008
* Corresponding author. Tel/Fax: +55-11-3069-7066; E-mail: gcih{at}hcnet.usp.br
Background: There has been an increase in worldwide infections caused by carbapenem-resistant Acinetobacter. This poses a therapeutic challenge as few treatment options are available.
Objectives: The aim of this study was to evaluate the efficacy and safety of polymyxins and ampicillin/sulbactam for treating infections caused by carbapenem-resistant Acinetobacter spp. and to evaluate prognostic factors.
Methods: This was a retrospective review of patients from two teaching hospitals who had nosocomial infections caused by carbapenem-resistant Acinetobacter spp. from 1996 to 2004. Diagnosis of infection was based on CDC criteria plus the isolation of Acinetobacter from a usually sterile site or from bronchoalveolar lavage. Urinary tract infections were not included. Data on demographic and clinical features and treatment were collected from medical records. Prognostic factors associated with two outcomes (mortality during treatment and in-hospital mortality) were evaluated.
Results: Eighty-two patients received polymyxins and 85 were treated with ampicillin/sulbactam. Multiple logistic regression analysis revealed that independent predictors of mortality during treatment were treatment with polymyxins, higher Acute Physiological and Chronic Health Evaluation II (APACHE II) score, septic shock, delay in starting treatment and renal failure. On multivariate analysis, prognostic factors for in-hospital mortality were older age, septic shock and higher APACHE II score.
Conclusions: This is the first study comparing current therapeutic options for infections due to carbapenem-resistant Acinetobacter. The most important finding of the present study is that ampicillin/sulbactam appears to be more efficacious than polymyxins, which was an independent factor associated with mortality during treatment.
Keywords: colistin , antibiotics , drug resistance