Inhalation plus intravenous colistin versus intravenous colistin alone for treatment of ventilator associated pneumonia

In the setting of intensive care units the incidences of multi-drug resistant gram-negative (MDR-GN) pathogens causing ventilator associated pneumonia (VAP) has increased, leading clinicians to use colistin. Our aim was to assess outcomes associated with the use of inhalation and intravenous colisitn versus only intravenous colistin in patients with MDR-GN VAP. A retrospective, single centre study at University Hospital Centre, Zagreb. Patients were divided in two groups, according to their administration of antibiotics - inhalation and intravenous (INH+IV) administration for 8 patients or intravenous only (IV) administration for 23 patients. The results showed that demographic and clinical characteristics and the gram negative pathogens isolated were similar between the two groups, except for K. pneumoniae, which was higher in the IV group. No statistically significant difference between the two groups were observed regarding intensive care unit mortality (P=0.951), sepsis (P=0.474), acute respiratory distress syndrome (P=0.548), length of ICU stay (P=0.686) and length of mechanical ventilation (P=0.858). A statistically significant difference was found regarding the eradication of pathogens in respiratory cultures (P=0.018). The addition of inhalation to intravenous colistin in MDR-GN VAP improves microbiologic outcome, but does not improve ICU mortality in these patients. Larger prospective trials are warranted to confirm the benefit of adjunctive inhalation colistin as a MDR-GN VAP therapy in the critically ill.