N-Acetylcysteine Supplementation for the Prevention of Postoperative Liver Dysfunction after On-Pump Cardiac Surgery

Background: Incidence of postoperative liver dysfunction continues to be high (ranging from 10 to 35%) in those who underwent cardiac surgeries using cardiopulmonary bypass (CPB) and is associated with considerable morbidity and mortality. Prolonged cardiopulmonary bypass time (CPBT) was found to be an independent predictor of postoperative liver dysfunction. So, the aim of this study was to evaluate the effect of prophylactic use of N-acetylcysteine (NAC) in patients undergoing on-pump cardiac surgery with expected prolonged CPBT in the prevention of liver dysfunction. Methods: Sixty consenting adult patients undergoing cardiac surgeries using CPB with CPBT more than 120 minutes were included in this single-centre, randomised, parallel-group, double-blinded interventional study. Study group patients received NAC as per the protocol. Liver transferases, alkaline phosphatase, serum bilirubin, kidney function tests, and coagulation parameters were measured preoperatively, on the day of surgery and for 3 days postoperatively. Results: Values for serum aminotransferase, alanine aminotransferase, and alkaline phosphatase were significantly raised in the control group compared to the study group, starting from the day of surgery till third postoperative day. Serum bilirubin levels (total and direct) were comparable till first postoperative day and were significantly raised on second and third postoperative days in the control group. Duration of mechanical ventilation, total chest tube drainage, the duration of ICU and hospital stay were significantly shorter in study group compared to control group. Conclusion: Prophylactic intravenous NAC has a protective role in preventing postoperative hepatic dysfunction in patients undergoing cardiac surgery with CPB.