Impact of Vitamin C Supplementation on Post-Cardiac Surgery delirium

Abstract

Delirium is the most common neurological diagnosis among the patients who are admitted to intensive care units. Delirium is experienced approximately by 30 and 50 percent of the patients who are admitted to surgical ICU and cardiac ICU (CCU), respectively. This study aimed to investigate the prophylactic effect of the Vitamin C Supplementation on Post-Cardiac Surgery delirium rate. Materials and Methods: This randomized clinical trial, was performed in 2019, on patients over 18 years of age who were candidates of elective cardiac surgery using cardiopulmonary bypass (CPB), at Shahid Madani Hospital in Tabriz. After obtaining the approval of the ethics committee of Tabriz University of Medical Sciences, informed written consent was obtained from all the patients. One hundred sixty patients were randomly assigned to one of the two groups of Vitamin C or placebo according to the prepared list (n=80). Immediately after the onset of CPB, according to a randomization list, 10 cc of Vitamin C solution or the same volume of distilled water was injected intravenously, in patients of the Vitamin C or placebo group, respectively. After admission to the ICU, vitamin C group received 1 g of intravenous vitamin C daily for two days. During, ICU stay, the incidence of the delirium investigated using CAM-ICU. In addition to recording demographic data, the data of the surgery, hemodynamic status, any complication, duration of mechanical ventilation, ICU stay and mortality were recorded and compared between the two groups. Results: The two groups were not different due to the demographic variables including age, gender and BMI. The ventricular ejection fraction was the same in both groups and the distribution of underlying disease and characters of the surgery (type of surgery, operation and CPB time) and post-operative (need for cardiac drugs, complications and time of mechanical ventilation and, ICU stay) were similar in the two groups. The overall prevalence of delirium was 22.8% (37 patients) which was clearly lower in the vitamin C group, than the placebo group (15.2% vs. 30.1%, P-value = 0.024).The results showed that in patients with delirium, the preoperative ventricular ejection fraction, was significantly lower than those without delirium, (P-value <0.001). On the other hand, data analysis showed that the duration of operation and CPB, bleeding rate at the first 24 hours, amount of the used units of blood products, duration of mechanical ventilation and ICU stay were significantly higher in patients with delirium, than those without delirium, (P-value <0.05).