Vitamin C in Post-cardiac Arrest

Only half of the patients suffering from cardiac arrest arrive at the hospital alive. Of these survivors, more than 50% will still die or remain severely disabled. During cardiac arrest ischemia causes damage to the vital organs, especially the brain. When with return of spontaneous circulation oxygen is re-offered to the ischemic organs, massive amounts of reactive oxygen species (ROS) are produced. These ROS can further increase the damage to the myocardium and brain (reperfusion injury). Vitamin C is the primary circulating antioxidant. It scavenges free radicals and reduces the production of ROS. In a recent study we demonstrated that vitamin C plasma levels are deficient in \~60% of the patients after cardiac arrest, probably due to massive consumption. Vitamin C deficiency reduces the protection against oxidative stress. Intravenous supplementation is needed to restore deficiency and the antioxidative effect of vitamin C is much more potent if it is administered in a supraphysiological dose (≥ 3 g per day). Its strong antioxidative effect may reduce damage to the circulation and to brain, heart and other organs. Beneficial effects of high dose i.v. vitamin C after cardiac arrest have been demonstrated in preclinical studies, but not in patients. The investigators hypothesize that vitamin C can reduce organ damage, especially cerebral injury, if administered for a short period as a high i.v. dose during the very early phase of reperfusion after cardiac arrest. Objectives: * To determine whether an early high dose i.v. vitamin C can improve organ function, especially neurological outcome, in patients after cardiac arrest * To explore the optimal dosing regimen for high dose i.v. vitamin C * To investigate in vitro the difference in effect of plasma obtained from post cardiac arrest patients treated with placebo, 3 gr/day or 10 gr/day vitamin C on endothelial cell viability and underlying oxidative pathways.