Effect of Intravenous Injection of Vitamin C on Postoperative Pulmonary Complications in Patients Undergoing Cardiac Surgery: A Double-Blind, Randomized Trial

Purpose: In this study, the effect of intravenous vitamin C during surgery on the incidence of postoperative pulmonary complications (PPCs) in patients undergoing cardiopulmonary bypass and cardiac surgery was observed, and its protective effect on the lungs was evaluated to provide a reference for clinical medication. Patients and Methods: Patients undergoing cardiac surgery under cardiopulmonary bypass (CPB) were selected. The patients were divided into group A and group C by random sequence. Patients in group A received intravenous vitamin C 1 g 10 minutes after induction of anesthesia, 10 minutes before cardiac reanimation and at the moment of sternal closure. Patients in group C were intravenously injected with the same volume of saline at the same time. The primary outcome was the postoperative pulmonary complication severity score. Other outcomes were the incidence of PPCs, awakening time, extubation time, length of ICU stay, length of hospital stay, adverse events, oxygenation index (PaO 2 /FiO 2 ), alveolar arterial oxygen partial pressure difference (A-aDO 2 ), dynamic lung compliance (Cd) and static lung compliance (Cs). Results: Seventy patients completed the study. Compared to group C, the postoperative pulmonary complication score 2(2– 3) vs 2(1– 2); P =0.009 and the incidence of postoperative pulmonary complications (32.43% vs 12.12%; P =0.043) were lower in group A. There were no significant differences in awakening time, extubation time, length of ICU stay, length of hospital stay, adverse events, PaO 2 /FiO 2 , A-aDO 2 , Cs, and Cd between the two groups ( P > 0.05). Conclusion: In summary, this small randomized trial including low-risk cardiac surgery patients shows that intravenous vitamin C may safely be administered and may be helpful to prevent PPCs after cardiac surgery. Keywords: cardiac surgery, cardiopulmonary bypass, postoperative pulmonary complications, vitamin C