Effect of ascorbic acid on inflammatory markers after cardiothoracic surgery

Abstract

The effect of ascorbic acid on inflammatory markers after cardiothoracic surgery (CTS) was studied. In this randomized, double-blind, placebo-controlled trial, patients undergoing cardiopulmonary bypass graft surgery or valve replacement surgery from April 2009 through March 2010 at Hartford Hospital were randomized to receive ascorbic acid (2-g loading dose followed by 500 mg every 12 hours) or matching placebo the evening before surgery and for four days postoperatively. Inflammatory mediators were measured preoperatively and on postoperative days 1-4. Intergroup comparisons were performed using two-tailed t tests and Fisher's exact test. Multiple comparisons were conducted using repeated analyses of variance with Bonferroni tests. Of the 62 patients screened, 24 met the study inclusion criteria. Of these, 13 were assigned to receive ascorbic acid and 11 received placebo. Ascorbic acid did not affect the natural course of inflammatory marker rise for C-reactive protein (CRP) concentration, white blood cell (WBC) count, or fibrinogen concentration versus placebo at any evaluated time point (p > 0.05 for all intergroup comparisons). Intragroup analyses demonstrated significant differences among baseline and postoperative measures of all inflammatory mediators (p < 0.05). No significant differences were noted in inflammatory markers between patients undergoing cardiothoracic surgery with or without cardiopulmonary bypass, regardless of treatment group. Ascorbic acid did not attenuate the rise in inflammatory markers after CTS when compared with placebo. The use of off-pump surgery did not significantly change the levels of CRP and fibrinogen or the WBC count postoperatively when compared with on-pump surgery with a biocompatible polymer coating.