Impact of Ascorbic Acid Treatment on the Development and Treatment of Vasodilation in Cardiac Surgery

Overview

This is a prospective pilot study in which the effects of ascorbic acid administration are investigated in adult patients undergoing cardiac surgical procedures requiring cardiopulmonary bypass (CPB). Ascorbic acid (Vitamin C) is an essential cofactor in the biosynthesis of catecholamines, and critically ill patients are known to be ascorbate-deficient. In addition, cardiopulmonary bypass (CPB) decreases ascorbic acid concentrations. Cardiac vasoplegia is the loss of vascular tone despite adequate volume status and cardiac output, occurring commonly in patients after CPB. This necessitates the administration of vasopressors and alternative agents which can have deleterious effects. The administration of ascorbic acid to cardiac surgical patients may improve microcirculatory function, enhance endogenous catecholamine levels and decrease the need for exogenous vasopressor support.

1\. Specific Aims The investigators aim to determine the feasibility of performing a study that can assess the impact of ascorbic acid administration on the development and severity of cardiac vasoplegia in cardiac surgical patients undergoing procedures at high risk for vasoplegia. Specific Aim 1: Determine the feasibility of administration of high dose intravenous ascorbic acid in the operative and post-operative environments as well as sample size for a prospective, randomized, placebo controlled study. Specific Aim 2: Determine baseline ascorbic acid plasma levels in a small cohort of cardiac surgical patients. Specific Aim 3: Determine the impact of ascorbic acid administration on microvasculature as measured by dark field microscopy.