IL18 and acute kidney injury: Serum creatinine measured on arrival in ICU had a higher value (AUC-ROCC 0.69, 95% confidence interval 0.54 to 0.85; P = 0.019) to predict AKI (defined as a creatinine increase of greater than 50% within 48 hours postoperatively) than urinary IL-18 at that time of measurement.