Vitamin C dosing during continuous renal replacement therapy: The last word is not said!
-
Patrick M. Honore
,
David De Bels
To the editor
Pharmacokinetic and dose-response data suggest a vitamin C (vit C) dose largely exceeding 3 g daily in critically ill patients. We recently proposed higher vit C dosing in cardiac arrest patients who require continuous renal replacement therapy (CRRT).[1] In a reaction, Spoelstra-de Man et al. rebutted that increasing the vit C dose above 2 g/day during continuous veno-venous hemofiltration (CVVH) was unnecessary when normal plasma vit C concentrations are targeted. They based their standpoint on calculating less vit C removal during CVVH than by a normally functioning kidney.[2]
We want to warn for too much oversimplification! First, Spoelstra-de Man et al. used CVVH, which is a sheer convective technique as opposed to continuous venovenous hemodialysis (CVVHD) and continuous veno-venous hemodiafiltration (CVVHDF). Being largely eliminated by diffusion, vit C will be more extensively cleared by CVVHD(F) than by CVVH. [3] Second, vit C plasma concentrations in the single CVVH-treated patient studied were approximately 200 μmol/L at CVVH initiation and were recorded for 48 h.[2] Vit C, however, is consistently deficient upon intensive care (IC) admission and levels continue to fall dramatically during the acute phase of surgery or critical illness.[4] In a patient with reduced vit C levels and normal renal function, the kidney will adapt and drive back vit C losses. In severely ill patients with low baseline or declining vit C levels, CRRT will continue to remove vit C regardless of plasma levels. Kamel et al. observed a pronounced vit C deficiency in 80% of patients receiving CRRT for a mean duration of 2 weeks despite a daily intravenous supplement of 500 to 1000 mg initiated within 7 days prior to measuring vit C levels.[5] At least one-third of the patients in this study were on CVVHD or CVVHDF. This underscores that more aggressive vit C supplementation is mandatory when CRRT runs for a prolonged time period and, in particular, when renal epuration modes that facilitate vit C elimination are applied. Third, vit C levels corresponding with a neat clinical effect in IC patients have not been determined. For instance, doubling target concentrations from 100 to 200 μmol/L would result in a daily CRRT-induced vit C loss of 1.7 g. Unless proven otherwise, we hold on to our recommendation to supplement up to 12 g vit C in patients undergoing CVVHD, CVVHDF or prolonged CVVH.
Conflict of Interest
The authors declare to have no competing interests.
References
1 Honore PM, De Bels D, Preseau T, Redant S, Attou R, Spapen HD. Adjuvant vitamin C in cardiac arrest patients undergoing renal replacement therapy: an appeal for a higher high-dose. Crit Care 2018; 22: 207.10.1186/s13054-018-2115-9Search in Google Scholar PubMed PubMed Central
2 Spoelstra-de Man AME, De Groot HJ, Elbers PWG, Oudemans-Van Straaten HM . Response to “Adjuvant vitamin C in cardiac arrest patients undergoing renal replacement therapy: an appeal for a higher high-dose”. Crit Care 2018; 22: 35010.1186/s13054-018-2200-0Search in Google Scholar PubMed PubMed Central
3 Fehrman-Ekholm I, Lotsander A, Logan K, Dunge D, Odar-Cederlöf I, Kallner A. Concentrations of vitamin C, vitamin B12 and folic acid in patients treated with hemodialysis and on-line hemodiafiltration or hemofiltration. Scand J Urol Nephrol 2008; 42: 74-80.10.1080/00365590701514266Search in Google Scholar PubMed
4 Carr AC, Rosengrave PC, Bayer S, Chambers S, Mehrtens J, Shaw GM. Hypovitaminosis C and vitamin C deficiency in critically ill patients despite recommended enteral and parenteral intakes. Crit Care 2017; 21: 300.10.1186/s13054-017-1891-ySearch in Google Scholar PubMed PubMed Central
5 Kamel AY, Dave NJ, Zhao VM, Griffith DP, Connor MJ Jr, Ziegler TR. Micronutrient Alterations During Continuous Renal Replacement Therapy in Critically Ill Adults: A Retrospective Study. Nutr Clin Pract 2018; 33: 439-46.10.1177/0884533617716618Search in Google Scholar PubMed
© 2019 Patrick M. Honore, David De Bels, Luc Kugener, Sebastien Redant, Rachid Attou, Andrea Gallerani, Herbert D. Spapen, published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.
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Articles in the same Issue
- Editorial
- Application of wearable technology in clinical walking and dual task testing
- Commentary
- A hypothetical approach on gender differences in cancer diagnosis
- Review Article
- Endoscopic Ultrasound-guided Gastroenterostomy: A Promising Alternative to Surgery
- Original Article
- Treatment of ventilator-associated pneumonia with high-dose colistin under continuous veno-venous hemofiltration
- Effect of weight reduction on histological activity and fibrosis of lean nonalcoholic steatohepatitis patient
- Case Report
- Elevated lactic acid during ketoacidosis: pathophysiology and management
- Intrahepatic portosystemic shunt in a young female: Views from a developing country
- Letter to the Editor
- Vitamin C dosing during continuous renal replacement therapy: The last word is not said!
