Lack of Effect of Prophylactic N-acetylcysteine on Postoperative Organ Dysfunction following Major Abdominal Tumour Surgery: A Randomized, Placebo-controlled, Double-blinded Clinical Trial

Sepsis and respiratory dysfunction leading to multiple system organ failure remains the leading cause of postoperative morbidity and mortality following major surgical procedures. It has been suggested the oxygen free radicals might play a pivotal role in this process. The aim of this study was to investigate whether short-term infusion of N-acetylcysteine (N-acetylcysteine), a potent antioxidant, administered before and during extensive abdominal surgery, could ameliorate the progression of early postoperative organ dysfunction and improve oxygenation. Out of the 93 patients, 47 received N-acetylcysteine and 46 were given placebo in a randomized, controlled, double-blinded fashion. Patients received N-acetylcysteine (150 mg.kg-1 bolus followed by a continuous infusion of 12 mg.kg-1.h-1) or the same volume of placebo (5% dextrose) during surgery. Treatment effect on organ function was assessed by organ dysfunction scores according to physiological parameters of six main organ systems: respiratory, cardiovascular, renal, hepatic, haematological and central nervous system. The scores were obtained on admission, then daily during the first three postoperative days. For statistical analysis Mann-Whitney U and Chi-squared tests were used. There was no significant difference between the two groups in any of the six organ dysfunction parameters, length of intensive care stay, days of mechanical ventilation and mortality. Our results do not support the routine use of N-acetylcysteine as a prophylactic measure during surgery, and reinforce previous evidence which challenges the indication of N-acetylcysteine in the critically ill.