Comparison of Intravenous Ampicillin–sulbactam Plus Nebulized Colistin with Intravenous Colistin Plus Nebulized Colistin in Treatment of Ventilator Associated Pneumonia Caused by Multi Drug Resistant Acinetobacter Baumannii: Randomized Open Label Trial

The purpose of this study was evaluating the efficacy and safety of intravenous (IV) ampicillin–sulbactam plus nebulized colistin in the treatment of Ventilator-Associated Pneumonia (VAP) caused by MDR Acinetobacter (MDRA) in ICU patients as an alternative to IV plus nebulized colistin. In this single-blinded RCT, one group received IV colistin and another group IV ampicillin–sulbactam (16 and 12 patients from total 28 patients, respectively) for 14 days or since clinical response. Both groups received nebulized colistin by mesh nebulizer. There were no statistically significant differences between the 2 groups in baseline characteristics and previous antibiotic therapy. In follow up period, no significant difference was observed between 2 groups in rate of microbiological eradication, clinical signs of VAP improvement, survival rate and length of hospital as well as ICU stays. Although we have found no significant differences in Acute Kidney Injury (AKI) incidence between two groups, comparison of cumulative patient-days with stages 2 and 3 AKI with days with no or stage 1 AKI, according to AKIN criteria, revealed significant difference in IV colistin versus IV ampicillin–sulbactam group (p = 0.013). The results demonstrated that the high dose IV ampicillin–sulbactam plus nebulized colistin regimen has comparable efficacy with IV plus nebulized colistin in the treatment of VAP caused by MDRA, with sensitivity to colistin only, with probably lower incidence of kidney injury.