Ampicillin/sulbactam compared with polymyxins for the treatment of infections caused by carbapenem-resistant Acinetobacter spp.
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.


OBJECTIVE
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.
Oliveira
M S
MS
Department of Infection Control of Hospital das Clínicas, Rua Dr Ovídio Pires de Campos, 225, Sala 629, São Paulo-SP 05403-010, Brazil. gcih@hcnet.usp.br
Prado
G V B
GV
Costa
S F
SF
Grinbaum
R S
RS
Levin
A S
AS
D018806:APACHE; D000150:Acinetobacter / Q000187:drug effects* / Q000302:isolation & purification; D000151:Acinetobacter Infections / Q000150:complications / Q000188:drug therapy* / Q000401:mortality; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000667:Ampicillin / Q000009:adverse effects / Q000627:therapeutic use; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D015780:Carbapenems / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D003428:Cross Infection / Q000150:complications / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality; D005260:Female; D006784:Hospitals, Teaching; D006801:Humans; D007223:Infant; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011113:Polymyxins / Q000009:adverse effects / Q000627:therapeutic use*; D011379:Prognosis; D051437:Renal Insufficiency; D012189:Retrospective Studies; D012307:Risk Factors; D012772:Shock, Septic / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality; D013407:Sulbactam / Q000009:adverse effects / Q000627:therapeutic use; D013997:Time Factors; D016896:Treatment Outcome; D018440:beta-Lactam Resistance
D015780:Carbapenems; D011113:Polymyxins; C035444:sultamicillin; D000667:Ampicillin; D013407:Sulbactam