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

Abstract

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.

Strategies to attenuate maladaptive inflammatory response associated with cardiopulmonary bypass

“…In another rat model of CPB, N-acetylcysteine was shown to ameliorate CPB-associated intestinal injury via reduction in inflammation and oxidative stress as measured by decreased levels of intestinal malondialdehyde, TNF-α, IL-6, and serum diamine oxidase ( 336 ). A number of studies have recently shown N-acetylcysteine to improve pulmonary, hepatic, and renal outcomes in patients undergoing CPB with and without preexisting pulmonary and renal insufficiency ( 337 – 342 ).…”

Biochemical Changes in Cardiopulmonary Bypass in Cardiac Surgery: New Insights

“…There are considerable biochemical changes during and after the CPB, such as oxygenation in non-endothelial membranes, reperfusion damage, absorption of nutrients in the CPB circuit [91,92]. This context of inflammation and oxidative stress has been associated with postoperative complications in these patients, such as atrial fibrillation, acute kidney and lung and liver injury [12,51,[93][94][95]. In this sense, several drugs with antioxidant properties are being investigated, either as individual therapies or in combined treatment to reduced oxidative damage.…”

“…In addition, NAC has exhibited important effects by reducing the levels of lactate and nitrogenous slags in the blood 24 h after cardiac surgery with CPB, suggesting a beneficial effect on peripheral and renal tissue perfusion [123]. Furthermore, the prophylactic use of NAC attenuates the liver damage induced by cardiopulmonary bypass during cardiac surgery, in addition to reducing the incidence of acute kidney injury in this type of surgery [93,[124][125][126]. However, more clinical studies are needed to standardize necessary doses and treatment times, as well as monitoring possible unwanted effects.…”