Estimating Vitamin C Status in Critically Ill Patients with a Novel Point-of-Care Oxidation-Reduction Potential Measurement

Abstract

Vitamin C deficiency is common in critically ill patients. Vitamin C, the most important antioxidant, is likely consumed during oxidative stress and deficiency is associated with organ dysfunction and mortality. Assessment of vitamin C status may be important to identify patients who might benefit from vitamin C administration. Up to now, vitamin C concentrations are not available in daily clinical practice. Recently, a point-of-care device has been developed that measures the static oxidation-reduction potential (sORP), reflecting oxidative stress, and antioxidant capacity (AOC). The aim of this study was to determine whether plasma vitamin C concentrations were associated with plasma sORP and AOC. Plasma vitamin C concentration, sORP and AOC were measured in three groups: healthy volunteers, critically ill patients, and critically ill patients receiving 2- or 10-g vitamin C infusion. Its association was analyzed using regression models and by assessment of concordance. We measured 211 samples obtained from 103 subjects. Vitamin C concentrations were negatively associated with sORP (R2 = 0.816) and positively associated with AOC (R2 = 0.842). A high concordance of 94–100% was found between vitamin C concentration and sORP/AOC. Thus, plasma vitamin C concentrations are strongly associated with plasma sORP and AOC, as measured with a novel point-of-care device. Therefore, measuring sORP and AOC at the bedside has the potential to identify and monitor patients with oxidative stress and vitamin C deficiency.

Rapid screening of critically ill patients for low plasma vitamin C concentrations using a point-of-care oxidation–reduction potential measurement

“…The RedoxSYS system (Aytu Bioscience, Englewood, CO, USA), a point-of-care device, is able to measure the static oxidation reduction potential (sORP) within 20 min in a sample volume of 30 µL [ 23 – 25 ]. It measures the balance between the total amount of oxidants and reductants in the plasma.…”

“…It measures the balance between the total amount of oxidants and reductants in the plasma. sORP appeared to be useful for the estimation of plasma vitamin C concentrations in critically ill patients and healthy volunteers, as shown in our recently published retrospective study using thawed plasma samples [ 23 ]. A strong negative relation was found between sORP and plasma vitamin C concentration.…”

Perioperative Vitamin C and E levels in Cardiac Surgery Patients and Their Clinical Significance

“…Our results regarding the oxidative stress are in line with the recently published study by Rozemeijer et al, who also observed an increase of oxidative stress in ICU-patients undergoing major surgery/sepsis or trauma, as well as in patients after cardiac arrest to similar levels we observed in patients undergoing cardiac surgery. Additionally, Rozemeijer et al observed a strong negative association of ORP and strong positive association between the anti-oxidative capacity with plasma vitamin C concentrations (R 2 > 0.8 for ORP and R 2 = 0.842 for anti-oxidative capacity) and demonstrated a strong concordance between changes in plasma vitamin C concentration and changes in severity of oxidative stress, reflecting that a high dose of vitamin C diminished the oxidative stress in their critically ill patients [36].…”

Vitamin C – neue Therapiemöglichkeit bei Sepsis?

“…Ein Vitamin-C-Mangel ist bei kritisch kranken Patientenund hier insbesondere bei Patienten mit Sepsis häufig [22].…”