Intravenous vitamin C in adults with sepsis in the intensive care unit: still LOV’IT?

Highlights in the clinical nutrition literature: A critical appraisal of current research

Within the American Society for Parenteral and Enteral Nutrition (ASPEN), the Physician Engagement Committee (PEC) was created in 2017 by the ASPEN Board of Directors with the goal of growing the physician community both nationally and internationally. The PEC meets each month throughout the year to develop educational and research initiatives. In 2022, the PEC began an initiative to systematically review and evaluate practice-changing literature annually with the overall aim to highlight these studies at the annual ASPEN conferences and to critically discuss the potential clinical implications. The objective of the held meeting session was to present identified key papers in the fields of critical care medicine, gastroenterology and hepatology, and adult internal medicine that were published in 2022, which would complement the knowledge of the pathogenesis, diagnosis, and management of nutrition topics as well as to identify areas of future research. Overall, several large-scale randomized controlled studies were identified in each of these sections, with practice-changing major results. This manuscript summarizes the information that was presented and the discussions that followed.

Vitamin C deficiency in critically ill COVID-19 patients admitted to intensive care unit

Objectives

To determine vitamin C plasma kinetics, through the measurement of vitamin C plasma concentrations, in critically ill Coronavirus infectious disease 2019 (COVID-19) patients, identifying eventually the onset of vitamin C deficiency.

Design

Prospective, observational, single-center study.

Setting

Intensive Care Unit (ICU), Vall d'Hebron University Hospital, Barcelona. Study period from November 12th, 2020, to February 24th, 2021.

Patients

Patients who had a severe hypoxemic acute respiratory failure due to COVID-19 were included.

Interventions

Plasma vitamin C concentrations were measured on days 1, 5, and 10 of ICU admission. There were no vitamin C enteral nor parenteral supplementation. The supportive treatment was performed following the standard of care or acute respiratory distress syndrome (ARDS) patients.

Measurement

Plasma vitamin C concentrations were analyzed using an ultra-performance liquid chromatography (UPLC) system with a photodiode array detector (wavelength set to 245 nm). We categorized plasmatic levels of vitamin C as follows: undetectable: < 1,5 mg/L, deficiency: <2 mg/L. Low plasma concentrations: 2-5 mg/L; (normal plasma concentration: > 5 mg/L).

Main results

Forty-three patients were included (65% men; mean age 62 ± 10 years). The median Sequential Organ Failure Assessment (SOFA) score was 3 (1-4), and the Acute Physiology and Chronic Health disease Classification System (APACHE II) score was 13 (10-22). Five patients had shock. Bacterial coinfection was documented in 7 patients (16%). Initially all patients required high-flow oxygen therapy, and 23 (53%) further needed invasive mechanical ventilation during 21 (± 10) days. The worst PaO2/FIO2 registered was 93 (± 29). ICU and hospital survival were 77 and 74%, respectively. Low or undetectable levels remained constant throughout the study period in the vast majority of patients.

Conclusion

This observational study showed vitamin C plasma levels were undetectable on ICU admission in 86% of patients with acute respiratory failure due to COVID-19 pneumonia requiring respiratory support. This finding remained consistent throughout the study period.

[Immunomodulation by nutritional intervention in critically ill patients]

Critically ill patients often suffer from a complex and severe immunological dysfunction. The differentiation and function of human immune cells are fundamentally controlled through metabolic processes. New concepts of immunonutrition therefore try to use enteral and parenteral nutrition to positively impact on the immune function of intensive care unit patients. This review article concisely presents the currently available evidence on the commonly used isolated supplements (anti-oxidative substances, amino acids, essential fatty acids) and difficulties related to their clinical use. The second part presents new and more comprehensive concepts of immunonutrition to influence the intestinal microbiome and to modulate the macronutrient composition. Immunonutrition of critically ill patients bears enormous potential and could become a valuable clinical tool for modulation of the immunometabolism of intensive care unit patients.

An update of the effects of vitamins D and C in critical illness

Many critically ill patients are vitamin D and vitamin C deficient and the current international guidelines state that hypovitaminoses should be compensated. However, uncertainty about optimal dosage, timing and indication exists in clinical routine, mainly due to the conflicting evidence. This narrative review discusses both micronutrients with regards to pathophysiology, clinical evidence of benefits, potential risks, and guideline recommendations. Evidence generated from the most recent clinical trials are summarized and discussed. In addition, pragmatic tips for the application of these vitamins in the clinical routine are given. The supplementations of vitamin D and C represent cost-effective and simple interventions with excellent safety profiles. Regarding vitamin D, critically ill individuals require a loading dose to improve 25(OH)D levels within a few days, followed by a daily or weekly maintenance dose, usually higher doses than healthy individuals are needed. For vitamin C, dosages of 100-200 mg/d are recommended for patients receiving parenteral nutrition, but needs may be as high as 2-3 g/d in acutely ill patients.

Kommentar zu „Intravenöse Vitamin C-Gabe: 28-Tage-Ergebnis septischer Patienten verschlechtert?“

Rarely the results of a study were expected so eagerly as the LOVIT trial, an acronym for “Lessening Organ Dysfunction with Vitamin C” 1. This blinded multicentric randomised trial (RCT) is a well-performed study 1 testing high-dose intravenous vitamin C (IVVC) (50 mg/kg every 6 h for 96hrs). With 872 patients, the trial is the largest so far. The results are sobering, as the patients receiving IVVC had a worse primary composite outcome compared to the placebo group: of note, the different components of the outcome (death or persistent organ dysfunction), did not differ significantly when considered individually 2.