A Pilot, Double-Blind, Randomized, Controlled Trial of High Dose Intravenous Vitamin C for Vasoplegia after Cardiac Surgery

Objective To conduct a pilot feasibility and physiologic efficacy study of high-dose vitamin C in patients with vasoplegia after cardiac surgery. Design Prospective, double-blind, randomized, controlled trial. Setting Two tertiary intensive care units (ICUs). Participants Post-cardiac surgery patients with vasoplegia. Interventions The authors randomly assigned the patients to receive either high-dose intravenous vitamin C (1,500 mg every 6 hours) or placebo. The primary outcome was time from randomization to resolution of vasoplegia. Secondary outcomes included total norepinephrine equivalent dose in the first 2 days, ICU length of stay, ICU mortality, and in-hospital mortality. Measurements and Main Results The authors studied 50 patients (25 patients in each arms). The mean (standard deviation) time to resolution of vasoplegia was 27.0 (16.5) hours in the vitamin C group versus 34.7 (41.1) hours in the placebo group (mean decrease with vitamin C of 7.7 hours, 95% confidence interval –10.5 to 25.9, p = 0.40). The median (interquartile range) norepinephrine equivalent dose in the first 2 days was 64.9 (23.5-236.5) µg/kg versus 47.4 (21.4-265.9) µg/kg in the vitamin C and placebo group (p = 0.75). The median duration of ICU admission was similar (1.4 [0.5-2.5] days and 1.5 [0.5-3.3] days in the vitamin C and placebo group; p = 0.36). Only 1 patient, in the vitamin C arm, died. Conclusion In patients with post-cardiac surgery vasoplegia, high-dose vitamin C infusion was feasible, appeared safe, and, within the limitations of a pilot study, did not achieve statistically faster resolution of vasoplegia.