Addition of Vitamin C Does Not Decrease Neuron-Specific Enolase Levels in Adult Survivors of Cardiac Arrest—Results of a Randomized Trial

Abstract

Background and Objectives: Survival with favorable neurologic outcomes after out-of-hospital cardiac arrest (OHCA) remains elusive. Post-cardiac arrest syndrome (PCAS) involves myocardial and neurological injury, ischemia-reperfusion response, and underlying pathology. Neurologic injury is a crucial determinant of survival and functional outcomes, with damage caused by free radicals among the responsible mechanisms. This study explores the feasibility of adding intravenous vitamin C to the treatment of OHCA survivors, aiming to mitigate PCAS. Vitamin C, a nutrient with antioxidative and free radical-scavenging properties, is often depleted in critically ill patients. Materials and Methods: This randomized, double-blinded trial was conducted at a tertiary-level university hospital with adult OHCA survivors. Participants received either standard care or the addition of 1.5 g of intravenous vitamin C every 12 h for eight consecutive doses. Neurologic injury was assessed using neuron-specific enolase (NSE) levels, with additional clinical and laboratory outcomes, such as enhanced neuroprognostication factors, inflammatory markers, and cardiac parameters. Results: NSE levels were non-significantly higher in patients who received vitamin C compared to the placebo group (55.05 µg/L [95% confidence interval (CI) 26.7–124.0] vs. 39.4 µg/L [95% CI 22.6–61.9], p > 0.05). Similarly, a non-significantly greater proportion of patients in the vitamin C group developed myoclonus in the first 72 h. We also observed a non-significantly shorter duration of mechanical ventilation, fewer arrhythmias, and reduced length of stay in the intensive care unit in the group of patients who received vitamin C (p = 0.031). However, caution is warranted in interpretation of our results due to the small number of participants. Conclusions: Our findings suggest that intravenous vitamin C should not be used outside of clinical trials for OHCA survivors. Due to the small sample size and conflicting results, further research is needed to determine the potential role of vitamin C in post-cardiac arrest care.