Introduction

The increased incidence of nosocomial infections by multidrug-resistant Acinetobacter baumannii creates demand on the application of some combinations of older antimicrobials on that species. We conducted the present observational study to evaluate the efficacy of intravenous and aerosolized colistin combined with rifampicin in the treatment of critically patients with nosocomial infections caused by multiresistant A. baumannii.

Methods

Critically ill patients with nosocomial infections caused by A. baumannii resistant to all antibiotics except colistin in a medical ICU were included. Diagnosis of infection was based on clinical data and isolation of bacteria. The bacterial susceptibilities to colistin were tested. Clinical response to colistin and rifampicin was evaluated.

Results

There were 26 patients (age 43.58 ± 18.29 years, APACHE II score 6.35 ± 2.99), of whom were 16 cases of nosocomial pneumonia treated by aerosolized colistin (1 × 106 IU three times/day) associated with intravenous rifampicin (10 mg/kg every 12 hours), nine cases of bacteraemia treated by intravenous colistin (2 × 106 IU three times/day) associated with intravenous rifampicin (10 mg/kg every 12 hours) in which three cases associated with ventilator-associated pneumonia, and one case of nosocomial meningitis treated by intrathecal use of colistin associated with intravenous rifampicin. The clinical evolution was favourable for all ill patients. Concerning side effects, we noticed a moderate hepatic cytolysis in three patients.

Conclusion

This is a clinical report of colistin combined with rifampicin for treatment of A. baumannii infection. Despite the lack of a control group and the limited number of patients, the results seem to be encouraging.