Variables determining the development of colistin-associated renal impairment

The aim of this study was to identify the predictors of acute renal injury associated with colistin treatment.

The patients who received treatment with colistin for more than 3 days were included in this retrospective cohort study. Acute renal injury was defined by the RIFLE (Risk Injury Failure Loss End stage renal disease) criteria. Patients whose serum creatinine levels increased at least 1.5-fold compared with baseline value were considered as cases with renal injury. The independent variables determining the development of acute renal injury were investigated by survival analysis.

A total of 112 cases [67 (59.8 %) were male, median age 64 (range: 18-93) years] were included in the study. Acute renal injury occurred in 66 (58.9 %) patients. Renal injury developed in first 7 days of the colistin therapy in 52 (78.8 %) cases and at day 8-23 in 14 (21.2 %) cases. On the day with highest levels of creatinine, 25 (22.3 %), 17 (15.2 %), and 33 (29.5 %) cases were in 'Risk', 'Injury', and 'Failure' group, respectively, according to RIFLE criteria. We identified three independent risk factors predicting acute colistin-induced renal injury: advanced age, low serum albumin levels, and high serum total bilirubin levels [odds ratio (confidence interval) = 1.022 (1.006-1.037), 0.643 (0.415-0.994), and 1.129 (1.014-1.257), respectively].

The advanced age, low serum albumin levels, and high serum total bilirubin levels are independent risk factors for colistin-induced nephrotoxicity.