High-dose vitamin C improves norepinephrine level in patients with septic shock: A single-center, prospective, randomized controlled trial

Abstract

Background: The effects of vitamin C supplementation on patients with septic shock remain controversial. We aimed to evaluate the effects of different vitamin C dosages on norepinephrine (NE) synthesis in adult patients with septic shock. Methods: A total of 58 patients with septic shock admitted to our intensive care unit (ICU) between July 2021 and December 2022 were included. Patients were randomly divided into 3 groups: high-dose vitamin C (150 mg/kg/d, group A), low-dose vitamin C (50 mg/kg/d, group B), and placebo (group C). NE synthesis-related indicators (dopamine-β-hydroxylase [DβH], tyrosine hydroxylase [TH], tetrahydrobiopterin [BH4], and dopamine [DA]), plasma NE, and vitamin C levels were measured every 24 hours and analyzed. All-cause mortality within 28 days and other clinical outcomes (including Acute Physiology and Chronic Health Evaluation [APACHE], Sequential Organ Failure Assessment [SOFA], and Multiple-Organ Dysfunction Syndrome [MODS] scores) were compared. Results: Changes in TH, BH4, and DβH levels at 96 hours in groups A and B were greater than those in group C. These differences became more pronounced over the course of the intravenous vitamin C administration. Significant differences between groups A and C were detected at 96-hours TH, 72-hours BH4, 96-hours BH4, 96-hours DA, and DβH levels every 24 hours. The 96-hours TH, 96-hours BH4, and 48-hours DβH in group B were significantly higher than those in group C. The NE levels every 24 hours in groups A and B were higher than those in group C, group A and group C had a statistically significant difference. The 96-hours exogenous NE dosage in groups A and B was significantly lower than that in group C. No significant reductions in APACHE, SOFA, or MODS scores were observed in the vitamin C group, including the duration of ICU stay and mechanical ventilation. The 28-days mortality was lower in groups A and B than in group C (0%, 10%, and 16.67%, P = .187), but the difference was not significant. Conclusion: For patients with septic shock, treatment with vitamin C significantly increased TH, BH4, and DβH levels and reduced the exogenous NE dosage, but did not significantly improve clinical outcomes.