Data Sources, Search Strategy, and Study Selection
Two reviewers searched MEDLINE (1990 to May 2020), EMBASE (1990 to May 2020), PUBMED (1990 to May 2020) for randomized controlled studies that compared any form of usage of NAC to placebo in adult patients (age above 18) undergoing cardiac surgery. The following search terms were employed to source for eligible studies: NAC, N-acetylcysteine, Cardiac surgery, Cardiac surgical procedures, Cardiac, Heart, Renal, Kidney, Acute Kidney Injury and Acute Renal failure. There was no language restriction but only papers written in English were included.