Impact of the initiation time of colistin treatment for Acinetobacter infections

This study aimed to address the relationship between the timing of colistin therapy and the outcome, defined as all-cause mortality in the intensive care unit (ICU). A retrospective study was undertaken in a 16-bed ICU of a 750-bed tertiary care hospital. A total of 46 patients who had been administered intravenous colistin treatment for colistin-susceptible-only Acinetobacter infections were included in the study. Colistin treatment was initiated in 26 (56.5 %) patients within 24 h of the diagnosis (early administration of colistin), whereas the rest of the patients had obtained delayed treatment (delayed administration of colistin). Of the 46 patients, 21 (45.6 %) died. With univariate analysis, age, age greater than 65 years, APACHE II score more than 20 at baseline, and delayed administration of colistin were found to be significant (p < 0.05). Logistic regression analysis revealed a significant association between delayed administration of colistin [adjusted odds ratio (OR), 5.06; confidence interval (CI), 1.18-21.67], and adverse outcome. Other variables included in the final model were underlying disease (OR, 2.81; CI, 1.15-6.84) and APACHE II score at baseline >20 (OR, 3.81; CI, 0.77-18.75). This study found that delayed administration of colistin and underlying disease were independently associated with adverse outcome.