Effects of N-acetyl cysteine on renal functions evaluated by blood neutrophil gelatinase-associated lipocalin levels in geriatric patients undergoing coronary artery bypass grafting

Objective: Recent conflicting studies on the renal effects of N-acetyl cysteine (NAC) after cardiac surgery have been published. The aim of this study was to evaluate the renal effects of NAC using neutrophil gelatinase-associated lipocalin (NGAL) blood levels in elderly patients undergoing coronary artery bypass grafting (CABG). Methods: This randomized, double-blinded, placebo-controlled study was conducted among geriatric patients (>65 years) scheduled to undergo CABG. A total of 60 consecutive patients were randomly assigned to 2 groups. The first group received I. V. NAC (n= 30) and the second group received placebo (n=30) at induction of anesthesia and then for 20 h. NGAL values were determined and conventional renal function tests were performed. Statistical analysis was performed using SPSS 17.0 (IL, Chicago, USA). A p value of <0.05 was considered statistically significant. Results: Plasma creatinine levels at 24 h postoperatively were significantly higher in the placebo group than in the NAC group (1.41 +/- 0.63 vs. 1.13 +/- 0.35; p<0.05). The mean serum NGAL levels at 3 h postoperatively were higher in the placebo group than in the NAC group (104.94 +/- 30.51 vs. 87.82 +/- 25.18; p<0.05). NGAL levels were similar between the groups at all other measurement time points. Plasma creatinine levels of >= 1.5 mg/ dL or >25% of the baseline value at any time during the study period were observed in 27% of patients in the NAC group and 37% of patients in the placebo group; the difference was statistically significant (p<0.05). Conclusion: In the present study, we found that I. V. NAC infusion in elderly patients undergoing CABG reduced the incidence of acute kidney injury as determined by blood NGAL and creatinine levels.