Epidemiology of contrast-associated acute kidney injury in ICU patients: a retrospective cohort analysis

Intensive care unit (ICU) patients frequently undergo contrast-enhanced radiographic examinations, which carries a risk for development of contrast-associated acute kidney injury (CA-AKI). Data on this in ICU patients are scarce. The aim of this study was therefore to evaluate the epidemiology and short- and long-term outcomes of CA-AKI in ICU patients.A retrospective single-centre cohort study covering the period 1 March 2004 to 31 December 2008 on ICU patients who underwent a radiography examination with parenteral administration of iodinated radio contrast media was conducted. Data analysis included univariate and multivariate analyses of patients with and without CA-AKI.A total of 787 ICU patients were included in the study. CA-AKI occurred in 128 (16.3%) and was associated with higher need for RRT [30 (4.6%) vs. 21 (16.4%), p 0.001], worse kidney function at discharge, longer length of ICU and hospital stay, and higher 28-day and 1-year mortality [28-day: 86 (13.1%) vs. 46 (35.9%), p 0.001, and 1-year: 158 (24.0%) vs. 71 (55.5%), p 0.001]. Higher serum creatinine, lower mean arterial pressure, and administration of diuretics and vasoactive therapy were associated with development of CA-AKI in multivariate analysis. After correction for confounders we found that CA-AKI was associated with 28-day mortality in this cohort of ICU patients (odds ratio = 2.742, 95% confidence interval 1.374-5.471).CA-AKI occurred in one out of six ICU patients who underwent a contrast-enhanced radiography examination and was associated with both short-and long-term worse outcomes such as need for RRT, worse kidney function at discharge, increased length of stay in the ICU and hospital, and mortality.