Methods: Between January 2010 and December 2011, 113 patients who underwent an isolated elective CABG with cardiopulmonary bypass (CPB) in our clinic were divided into two groups. Routine renal functions and serum NGAL were measured in group 1 (33 males, 20 females; mean age 63.6±7.2 years; range 50 to 73 years), while only routine renal functions were measured in group 2 (40 males, 20 females; mean age 64.6±8.3 years; range 49 to 76 years). Parameters were collected at 2, 24 and 72 hours after CPB. Renal injury was defined as serum creatinine level exceeding 1.2 mg/dL. Based on this definition, study groups were divided into subgroups. A possible correlation between serum NGAL values and development of acute renal failure in the early postoperative period was investigated in between the groups and subgroups.

Results: All patients with renal injury according to the measurements of serum NGAL values at two hours following CPB had renal injury based on serum creatinine measurements at 72 hours of CPB. All patients without renal injury based on serum creatinine measurements at 72 hours of CPB did not have renal injury based on NGAL measurements at two hours of CPB. Serum NGAL values at two hours after CPB appeared to be determinants in predicting the development of acute renal injury at 72 hours.

Conclusion: Elevated levels of serum NGAL at two hours after CPB are strong indicators of renal injury and may be an early warning on the measures to be taken. Serum creatinine levels are usually increased in the late stage and, therefore, renal injury can not be prevented when detected.