Colistin in the treatment of infections from multiresistant Gram (-) bacilli
KeywordsCreatinine Pneumonia Respiratory Failure Creatinine Clearance Intravenous Infusion
To present our experience with i.v. colistin in the treatment of infections with multiresistant Gram (-) bacilli.
Materials and methods
Fourteen patients aged 20–81 years old, with severe infection from multiresistant Gram (-) bacilli, sensitive only to colistin. Of the patients, 11 were critically ill and mechanically ventilated, with an APACHE II score 8–22, and the other three were non-intubated patients with acute respiratory failure, treated in the ward. All patients received intravenous colistin (150,000 U/kg i.v., adjusted for creatinine clearance). A second antibiotic (in 11 cases high-dose b-lactam in continuous intravenous infusion) was added in the regimen. In total 16 courses of i.v. colistin were given, for the following infections: ventilator-associated pneumonia (VAP) (nine cases), nosocomial pneumonia in non-intubated patients (three), sepsis of unknown primary origin (one), urosepsis (one), catheter-related sepsis (two). In all cases, in spite of documented resistance, was included in the therapeutic regimen. The bacteria responsible were P. Aeruginosa (14 cases) or Acinetobacter baumanii (two cases). All patients had serum creatinine < 2.5 g/dl and none was oliguric.
Clinical response was observed in 12 cases. Thirty day survival was 71.4%. As regards VAP, six of nine cases had a good response. A slight deterioration in renal function was observed in three cases.
The small number of patients and the absence of a control group does not allow any definite conclusions on the clinical effectiveness of colistin. On the other hand we did not notice the daunting complications attributed to colistin in studies from the 1960s. Therefore, pending a definite controlled trial, intravenous colistin use should be considered in severe infections with multiresistant Gram (-) bacilli, when it remains the only sensitive in vitro antibiotic.