Intravenous Vitamin C in Adults with Sepsis in the Intensive Care Unit

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.

The effects of antioxidant supplementation on short-term mortality in sepsis patients

Background

The occurrence and development of sepsis are related to the excessive production of oxygen free radicals and the weakened natural clearance mechanism. Further dependable evidence is required to clarify the effectiveness of antioxidant therapy, especially its impact on short-term mortality.

Objectives

The purpose of this systematic review and meta-analysis was to evaluate the effect of common antioxidant therapy on short-term mortality in patients with sepsis.

Methods

According to PRISMA guidelines, a systematic literature search on antioxidants in adults sepsis patients was performed on PubMed/Medline, Embase, and the Cochrane Library from the establishment of the database to November 2023. Antioxidant supplements can be a single-drug or multi-drug combination: HAT (hydrocortisone, ascorbic acid, and thiamine), ascorbic acid, thiamine, N-acetylcysteine and selenium. The primary outcome was the effect of antioxidant treatment on short-term mortality, which included 28-day mortality, in-hospital mortality, intensive care unit mortality, and 30-day mortality. Subgroup analyses of short-term mortality were used to reduce statistical heterogeneity and publication bias.

Results

Sixty studies of 130,986 sepsis patients fulfilled the predefined criteria and were quantified and meta-analyzed. Antioxidant therapy reduces the risk of short-term death in sepsis patients by multivariate meta-analysis of current data, including a reduction of in-hospital mortality (OR = 0.81, 95% CI 0.67 to 0.99; P = 0.040) and 28-day mortality (OR = 0.81, 95% CI 0.69 to 0.95]; P = 0.008). Particularly in subgroup analyses, ascorbic acid treatment can reduce in-hospital mortality (OR = 0.66, 95% CI 0.90 to 0.98; P = 0.006) and 28-day mortality (OR = 0.43, 95% CI 0.24 to 0.75; P = 0.003). However, the meta-analysis of RCTs found that antioxidant therapy drugs, especially ascorbic acid, did substantially reduce short-term mortality(OR = 0.78, 95% CI 0.62 to 0.98; P = 0.030; OR = 0.57, 95% CI 0.36 to 0.91; P = 0.020).

Conclusions

According to current data of RCTs, antioxidant therapy, especially ascorbic acid, has a trend of improving short-term mortality in patients with sepsis, but the evidence remains to be further demonstrated.

Blood microbial signatures associated with mortality in patients with sepsis: A pilot study

Sepsis is a life-threatening illness caused by the dysregulated host response to infection. Nevertheless, our current knowledge of the microbial landscape in the blood of septic patients is still limited. Next-generation sequencing (NGS) is a sensitive method to quantitatively characterize microbiomes at various sites of the human body. In this study, we analyzed the blood microbial DNA of 22 adult patients with sepsis and 3 healthy subjects. The presence of non-human DNA was identified in both healthy and septic subjects. Septic patients had a markedly altered microbial DNA profile compared to healthy subjects over α- and β-diversity. Unexpectedly, the patients could be further divided into two subgroups (C1 and C2) based on β-diversity analysis. C1 patients showed much higher bacteria, viruses, fungi, and archaea abundance, and a higher level of α-diversity (Chao1, Observed and Shannon index) than both C2 patients and healthy subjects. The most striking difference was seen in the case of Streptomyces violaceusniger, Phenylobacterium sp. HYN0004, Caulobacter flavus, Streptomyces sp. 11-1-2, and Phenylobacterium zucineum, the abundance of which was the highest in the C1 group. Notably, C1 patients had a significantly poorer outcome than C2 patients. Moreover, by analyzing the patterns of microbe-microbe interactions in healthy and septic subjects, we revealed that C1 and C2 patients exhibited distinct co-occurrence and co-exclusion relationships. Together, our study uncovered two distinct microbial signatures in the blood of septic patients. Compositional and ecological analysis of blood microbial DNA may thus be useful in predicting mortality of septic patients.

Managing sepsis and septic shock in an endothelial glycocalyx-friendly way: from the viewpoint of surviving sepsis campaign guidelines

Maintaining tissue perfusion in sepsis depends on vascular integrity provided by the endothelial glycocalyx, the critical layer covering the luminal surface of blood vessels. The glycocalyx is composed of proteoglycans, glycosaminoglycans, and functional plasma proteins that are critical for antithrombogenicity, regulating tone, controlling permeability, and reducing endothelial interactions with leukocytes and platelets. Degradation of the glycocalyx in sepsis is substantial due to thromboinflammation, and treatments for sepsis and septic shock may exacerbate endotheliopathy via additional glycocalyx injury. As a result, therapeutic strategies aimed at preserving glycocalyx integrity should be considered, including modifications in fluid volume resuscitation, minimizing catecholamine use, controlling hyperglycemia, and potential use of corticosteroids and anticoagulants. In this review, we explore treatment strategies aligned with the recommendations outlined in the Surviving Sepsis Campaign Guidelines 2021 with a special emphasis on evidence regarding glycocalyx protection.

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

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.

Micronutrients as therapy in critical illness

PURPOSE OF REVIEW

Recent large-scale randomized controlled trials (RCTs) challenged current beliefs about the potential role of micronutrients to attenuate the inflammatory response and improve clinical outcomes of critically ill patients. The purpose of this narrative review is to provide an overview and critical discussion about most recent clinical trials, which evaluated the clinical significance of a vitamin C, vitamin D, or selenium administration in critically ill patients.

RECENT FINDINGS

None of the most recent large-scale RCTs could demonstrate any clinical benefits for a micronutrient administration in ICU patients, whereas a recent RCT indicated harmful effects, if high dose vitamin C was administered in septic patients. Following meta-analyses could not confirm harmful effects for high dose vitamin C in general critically ill patients and indicated benefits in the subgroup of general ICU patients with higher mortality risk. For vitamin D, the most recent large-scale RCT could not demonstrate clinical benefits for critically ill patients, whereas another large-scale RCT is still ongoing. The aggregated and meta-analyzed evidence highlighted a potential role for intravenous vitamin D administration, which encourages further research. In high-risk cardiac surgery patients, a perioperative application of high-dose selenium was unable to improve patients' outcome. The observed increase of selenium levels in the patients' blood did not translate into an increase of antioxidative or anti-inflammatory enzymes, which illuminates the urgent need for more research to identify potential confounding factors.

SUMMARY

Current data received from most recent large-scale RCTs could not demonstrate clinically meaningful effects of an intervention with either vitamin C, vitamin D, or selenium in critically ill patients. More attention is needed to carefully identify potential confounding factors and to better evaluate the role of timing, duration, and combined strategies.

Effect of high-dose vitamin C on renal ischemia-reperfusion injury

Acute kidney injury frequently occurs after cardiac surgery, and is primarily attributed to renal ischemia-reperfusion (I/R) injury and inflammation from surgery and cardiopulmonary bypass. Vitamin C, an antioxidant that is often depleted in critically ill patients, could potentially mitigate I/R-induced oxidative stress at high doses. We investigated the effectiveness of high-dose vitamin C in preventing I/R-induced renal injury. The ideal time and optimal dosage for administration were determined in a two-phase experiment on Sprague-Dawley rats. The rats were assigned to four groups: sham, IRC (I/R + saline), and pre- and post-vitC (vitamin C before and after I/R, respectively), with vitamin C administered at 200 mg/kg. Additional groups were examined for dose modification based on the optimal timing determined: V100, V200, and V300 (100, 200, and 300 mg/kg, respectively). Renal I/R was achieved through 45 min of ischemia followed by 24 h of reperfusion. Vitamin C administration during reperfusion significantly reduced renal dysfunction and tubular damage, more than pre-ischemic administration. Doses of 100 and 200 mg/kg during reperfusion reduced oxidative stress markers, including myeloperoxidase and inflammatory responses by decreasing high mobility group box 1 release and nucleotide-binding and oligomerization domain-like receptor 3 inflammasome. Overall beneficial effect was most prominent with 200 mg/kg. The 300 mg/kg dose, however, showed no additional benefits over the IRC group regarding serum blood urea nitrogen and creatinine levels and histological evaluation. During reperfusion, high-dose vitamin C administration (200 mg/kg) significantly decreased renal I/R injury by effectively attenuating the major triggers of oxidative stress and inflammation.

Role of vitamin C in treatment of community-acquired pneumonia in adult patients requiring hospitalisation: a systematic review protocol

INTRODUCTION

Community-acquired pneumonia (CAP) is a leading cause of hospitalisation and is associated with a high mortality. Vitamin C is a powerful antioxidant and has been used in treatment of infections; however, its role as an adjunctive treatment in CAP is unclear. This review aims to assess the efficacy and safety of vitamin C in adults who require hospitalisation for CAP.

METHODS AND ANALYSES

Searches will be conducted from inception to November 2023 on Ovid MEDLINE Daily and MEDLINE, Embase CINAHL, the Cochrane Central Register of Controlled Trials, Scopus, Web of Science and ClinicalTrials.gov databases with the aid of a medical librarian. We will include data from randomised controlled trials reporting vitamin C supplementation in patients with CAP requiring hospitalisation. Two independent reviewers will select studies, extract data and will assess the risk of bias by use of the Risk of Bias tool. The overall certainty of evidence will be assessed by use of the Grading of Recommendations Assessment, Development and Evaluation framework. Random-effects meta-analyses will be conducted, and effect measures will be reported as relative risks with 95% CIs.

ETHICS AND DISSEMINATION

No previous ethical approval is required for this review. The findings of this review will be submitted to a scientific journal and presented at an international medical conference.

PROSPERO REGISTRATION NUMBER

483860.

Neuroprotection Role of Vitamin C by Upregulating Glutamate Transporter-1 in Auditory Cortex of Noise-Induced Tinnitus Animal Model

Vitamin C (Vc) plays a pivotal role in a series of pathological processes, such as tumors, immune diseases, and neurological disorders. However, its therapeutic potential for tinnitus management remains unclear. In this study, we find that Vc relieves tinnitus in noise-exposed rats. In the 7-day therapy groups, spontaneous firing rate (SFR) increases from 1.17 ± 0.10 Hz to 1.77 ± 0.15 Hz after noise exposure. Vc effectively reduces the elevated SFR to 0.99 ± 0.07 and 0.55 ± 0.05 Hz at different doses. The glutamate level in auditory cortex of noise-exposed rats (3.78 ± 0.42 μM) increases relative to that in the control group (1.34 ± 0.22 μM). High doses of Vc (500 mg/kg/day) effectively reduce the elevated glutamate levels (1.49 ± 0.28 μM). Mechanistic studies show that the expression of glutamate transporter 1 (GLT-1) is impaired following noise exposure and that Vc treatment effectively restores GLT-1 expression in the auditory cortex. Meanwhile, the GLT-1 inhibitor, dl-threo-beta-benzyloxyaspartic acid (dl-TBOA), invalidates the protection role of Vc. Our finding shows that Vc substantially enhances glutamate clearance by upregulating GLT-1 and consequently alleviates noise-induced tinnitus. This study provides valuable insight into a novel biological target for the development of therapeutic interventions that may prevent the onset of tinnitus.

Vitamin C deficiency can lead to pulmonary hypertension: a systematic review of case reports

BACKGROUND

In the early literature, unintentional vitamin C deficiency in humans was associated with heart failure. Experimental vitamin C deficiency in guinea pigs caused enlargement of the heart. The purpose of this study was to collect and analyze case reports on vitamin C and pulmonary hypertension.

METHODS

We searched Pubmed and Scopus for case studies in which vitamin C deficiency was considered to be the cause of pulmonary hypertension. We selected reports in which pulmonary hypertension was diagnosed by echocardiography or catheterization, for any age, sex, or dosage of vitamin C. We extracted quantitative data for our analysis. We used the mean pulmonary artery pressure (mPAP) as the outcome of primary interest.

RESULTS

We identified 32 case reports, 21 of which were published in the last 5 years. Dyspnea was reported in 69%, edema in 53% and fatigue in 28% of the patients. Vitamin C plasma levels, measured in 27 cases, were undetectable in 24 and very low in 3 cases. Diet was poor in 30 cases and 17 cases had neuropsychiatric disorders. Right ventricular enlargement was reported in 24 cases. During periods of vitamin C deficiency, the median mPAP was 48 mmHg (range 29-77 mmHg; N = 28). After the start of vitamin C administration, the median mPAP was 20 mmHg (range 12-33 mmHg; N = 18). For the latter 18 cases, mPAP was 2.4-fold (median) higher during vitamin C deficiency. Pulmonary vascular resistance (PVR) during vitamin C deficiency was reported for 9 cases, ranging from 4.1 to 41 Wood units. PVR was 9-fold (median; N = 5) higher during vitamin C deficiency than during vitamin C administration. In 8 cases, there was direct evidence that the cases were pulmonary artery hypertension (PAH). Probably the majority of the remaining cases were also PAH.

CONCLUSIONS

The cases analyzed in our study indicate that pulmonary hypertension can be one explanation for the reported heart failure of scurvy patients in the early literature. It would seem sensible to measure plasma vitamin C levels of patients with PH and examine the effects of vitamin C administration.

Oxidative Stress and Cerebral Vascular Tone: The Role of Reactive Oxygen and Nitrogen Species

The brain's unique characteristics make it exceptionally susceptible to oxidative stress, which arises from an imbalance between reactive oxygen species (ROS) production, reactive nitrogen species (RNS) production, and antioxidant defense mechanisms. This review explores the factors contributing to the brain's vascular tone's vulnerability in the presence of oxidative damage, which can be of clinical interest in critically ill patients or those presenting acute brain injuries. The brain's high metabolic rate and inefficient electron transport chain in mitochondria lead to significant ROS generation. Moreover, non-replicating neuronal cells and low repair capacity increase susceptibility to oxidative insult. ROS can influence cerebral vascular tone and permeability, potentially impacting cerebral autoregulation. Different ROS species, including superoxide and hydrogen peroxide, exhibit vasodilatory or vasoconstrictive effects on cerebral blood vessels. RNS, particularly NO and peroxynitrite, also exert vasoactive effects. This review further investigates the neuroprotective effects of antioxidants, including superoxide dismutase (SOD), vitamin C, vitamin E, and the glutathione redox system. Various studies suggest that these antioxidants could be used as adjunct therapies to protect the cerebral vascular tone under conditions of high oxidative stress. Nevertheless, more extensive research is required to comprehensively grasp the relationship between oxidative stress and cerebrovascular tone, and explore the potential benefits of antioxidants as adjunctive therapies in critical illnesses and acute brain injuries.

Predicting hypovitaminosis C with LASSO algorithm in adult critically ill patients in surgical intensive care units: a bi-center prospective cohort study

Vitamin C played pleiotropic roles in critical illness and vitamin C insufficiency was predictive of the development of multiple organ failure. Currently, the prevalence of vitamin C insufficiency in Chinese critically ill patients is rarely determined and there are no established bedside tools to predict hypovitaminosis C. To develop a nomogram to identify patients with high risk of hypovitaminosis C, we performed a bi-center prospective cohort study at two ICUs of the first and sixth medical center in PLA General Hospital, Beijing, China from May 6th to July 31st, 2021 We identified 322 eligible patients. 62.4% patients were hypovitaminosis C. 7 features, including source of infection, the level of serum albumin, age, male gender, sepsis, vascular disease, and wasting of vitamin C by the kidney, were selected using LASSO algorithm and therefore included in the nomogram. In the testing set, our model showed moderate discrimination ability with areas under the curve of 0.75 [0.64-0.84]. Variable importance evaluated by SHAP value highlighted two novel important predictors, i.e., abdominal infection and the level of serum albumin. In conclusion, we first reported a high burden of vitamin C insufficiency in Chinese adult patient in the ICU. We also constructed a prediction model to timely identify patients with high risk of hypovitaminosis C, which allows the clinicians to choose appropriate candidates for Vitamin C repletion in clinical practice or clinical trials.

ESPEN practical short micronutrient guideline

BACKGROUND

Trace elements and vitamins, named together micronutrients (MNs), are essential for human metabolism. The importance of MNs in common pathologies is recognized by recent research, with deficiencies significantly impacting the outcome.

OBJECTIVE

This short version of the guideline aims to provide practical recommendations for clinical practice.

METHODS

An extensive search of the literature was conducted in the databases Medline, PubMed, Cochrane, Google Scholar, and CINAHL for the initial guideline. The search focused on physiological data, historical evidence (for papers published before PubMed release in 1996), and observational and/or randomized trials. For each MN, the main functions, optimal analytical methods, impact of inflammation, potential toxicity, and provision during enteral or parenteral nutrition were addressed. The SOP wording was applied for strength of recommendations.

RESULTS

The limited number of interventional trials prevented meta-analysis and led to a low level of evidence for most recommendations. The recommendations underwent a consensus process, which resulted in a percentage of agreement (%): strong consensus required of >90 % of votes. Altogether the guideline proposes 3 general recommendations and specific recommendations for the 26 MNs. Monitoring and management strategies are proposed.

CONCLUSION

This short version of the MN guideline should facilitate handling of the MNs in at-risk diseases, whilst offering practical advice on MN provision and monitoring during nutritional support.

To C or not to C? Designing a Pragmatic Trial to Deploy a Novel Immunomodulatory Therapy to Fight Organ Dysfunction in Sepsis

Angadi VM, Jindal A. To C or not to C? Designing a Pragmatic Trial to Deploy a Novel Immunomodulatory Therapy to Fight Organ Dysfunction in Sepsis. Indian J Crit Care Med 2024;28(3):311.

Adverse Clinical Effects Associated With Non-catecholamine Pharmacologic Agents for Treatment of Vasoplegic Syndrome in Adult Cardiac Surgery

Vasoplegic syndrome is a relatively common complication that can happen during and after major adult cardiac surgery. It is associated with a higher rate of complications, including postoperative renal failure, longer duration of mechanical ventilation, and intensive care unit stay, as well as increased mortality. The underlying pathophysiology of vasoplegic syndrome is that of profound vascular hyporesponsiveness, and involves a complex interplay among inflammatory cytokines, cellular surface receptors, and nitric oxide (NO) production. The pharmacotherapy approaches for the treatment of vasoplegia include medications that increase vascular smooth muscle contraction via increasing cytosolic calcium in myocytes, reduce the vascular effects of NO and inflammation, and increase the biosynthesis of and vascular response to norepinephrine. Clinical trials have demonstrated the clinical efficacy of non-catecholamine pharmacologic agents in the treatment of vasoplegic syndrome. With an increase in their use today, it is important for clinicians to understand the adverse clinical outcomes and patient risk profiles associated with these agents, which will allow better-tailored medical therapy.

Author Response

Tirupakuzhi Vijayaraghavan BK, Venkataraman R, Ramakrishnan N. Author Response. Indian J Crit Care Med 2024;28(3):312.

The mitochondrial signature of cultured endothelial cells in sepsis: Identifying potential targets for treatment

Sepsis is the most common cause of death from infection in the world. Unfortunately, there is no specific treatment for patients with sepsis, and management relies on infection control and support of organ function. A better understanding of the underlying pathophysiology of this syndrome will help to develop innovative therapies. In this regard, it has been widely reported that endothelial cell activation and dysfunction are major contributors to the development of sepsis. This review aims to provide a comprehensive overview of emerging findings highlighting the prominent role of mitochondria in the endothelial response in in vitro experimental models of sepsis. Additionally, we discuss potential mitochondrial targets that have demonstrated protective effects in preclinical investigations against sepsis. These promising findings hold the potential to pave the way for future clinical trials in the field.

Resuscitation With Vitamin C, Hydrocortisone, and Thiamin in Children With Septic Shock: A Multicenter Randomized Pilot Study

OBJECTIVES

Adjunctive therapy with vitamin C, hydrocortisone, and thiamin has been evaluated in adults, but randomized controlled trial (RCT) data in children are lacking. We aimed to test the feasibility of vitamin C, hydrocortisone, and thiamin in PICU patients with septic shock; and to explore whether the intervention is associated with increased survival free of organ dysfunction.

DESIGN

Open-label parallel, pilot RCT multicenter study. The primary endpoint was feasibility. Clinical endpoints included survival free of organ dysfunction censored at 28 days and nine secondary outcomes, shock reversal, and two proxy measures of intervention efficacy.

SETTING

Six PICUs in Australia and New Zealand.

PATIENTS

Children of age between 28 days and 18 years requiring vasoactive drugs for septic shock between August 2019 and March 2021.

INTERVENTIONS

Patients were assigned 1:1 to receive 1 mg/kg hydrocortisone every 6 hours (q6h), 30 mg/kg ascorbic acid q6h, and 4 mg/kg thiamin every 12 hours (n = 27), or standard septic shock management (n = 33).

MEASUREMENTS AND MAIN RESULTS

Sixty of 77 (78%) eligible patients consented with 91% of approached parents providing consent. The median time from randomization to intervention was 44 (interquartile range [IQR] 29-120) min. Seventy of seventy-seven (28%) patients had received IV steroids before randomization. Median survival alive and free of organ dysfunction was 20.0 (0.0-26.0) days in the intervention and 21.0 (0.0-25.0) days in the standard care group. Median PICU length of stay was 5.3 (2.5-11.3) days in the intervention group versus 6.9 (3.0-11.5) days in the control group. Shock reversal occurred at a median of 35.2 (14.6-101.2) hours in the intervention group versus 47.3 (22.4-106.8) hours in the standard care group (median difference -12 hr; 95% CI, -56.8 to 32.7 hr).

CONCLUSIONS

In children requiring vasopressors for septic shock, a protocol comparing adjunctive treatment with high-dose vitamin C, hydrocortisone, and thiamin versus standard care was feasible. These findings assist in making modifications to the trial protocol to enable a better-designed larger RCT.

High-dose ascorbic acid potentiates immune modulation through STAT1 phosphorylation inhibition and negative regulation of PD-L1 in experimental sepsis

Sepsis is a complex, multifactorial syndrome characterized by a dysregulated host response to infection, leading to severe organ dysfunction and high mortality rates among critically ill patients. Hypovitaminosis C and vitamin C deficiency are frequently observed in septic patients, prompting interest in the potential therapeutic role of ascorbic acid. Although intravenous administration of ascorbic acid has been investigated in multiple clinical trials for sepsis treatment, the specific immunomodulatory mechanisms underlying its effects remain elusive. This study aimed to investigate the protective effects of high-dose ascorbic acid on experimental sepsis. Results show that intravenous administration of high-dose ascorbic acid (250 mg/kg) attenuated sepsis-induced organ dysfunctions in a cecal ligation and puncture (CLP)-induced septic mouse model. Ascorbic acid improved splenic cell apoptosis and increased the number of CD3+ T cells in septic mice induced by CLP. Furthermore, ascorbic acid downregulated PD-L1 expression in livers, reduced PD-1 expression in spleens, and inhibited the phosphorylation of STAT1 at Y701 in multiple organs of CLP-induced septic mice. The in vitro experiments also revealed that 800 μM ascorbic acid suppressed STAT1 phosphorylation and inhibited lipopolysaccharide (LPS) and IFN-γ-induced PD-L1 expression in macrophages. These findings suggest that ascorbic acid prevents sepsis-associated organ dysfunction through the p-STAT1/PD-L1 signaling pathway. Our study provides new insights into the potential therapeutic use of ascorbic acid in sepsis.

Cell-Free Hemoglobin in the Pathophysiology of Trauma: A Scoping Review

OBJECTIVES

Cell-free hemoglobin (CFH) is a potent mediator of endothelial dysfunction, organ injury, coagulopathy, and immunomodulation in hemolysis. These mechanisms have been demonstrated in patients with sepsis, hemoglobinopathies, and those receiving transfusions. However, less is known about the role of CFH in the pathophysiology of trauma, despite the release of equivalent levels of free hemoglobin.

DATA SOURCES

Ovid MEDLINE, Embase, Web of Science Core Collection, and BIOSIS Previews were searched up to January 21, 2023, using key terms related to free hemoglobin and trauma.

DATA EXTRACTION

Two independent reviewers selected studies focused on hemolysis in trauma patients, hemoglobin breakdown products, hemoglobin-mediated injury in trauma, transfusion, sepsis, or therapeutics.

DATA SYNTHESIS

Data from the selected studies and their references were synthesized into a narrative review.

CONCLUSIONS

Free hemoglobin likely plays a role in endothelial dysfunction, organ injury, coagulopathy, and immune dysfunction in polytrauma. This is a compelling area of investigation as multiple existing therapeutics effectively block these pathways.

Association between acetaminophen administration and clinical outcomes in patients with sepsis admitted to the ICU: a retrospective cohort study

Background

Sepsis, affecting over 30 million people worldwide each year, is a key mortality risk factor in critically ill patients. There are significant regional discrepancies in its impact. Acetaminophen, a common over-the-counter drug, is often administered to control fever in suspected infection cases in intensive care units (ICUs). It is considered generally safe when used at therapeutic levels. Despite its widespread use, there's inconsistent research regarding its efficacy in sepsis management, which creates uncertainties for ICU doctors about its possible advantages or harm. To address this, we undertook a retrospective cohort study utilizing the MIMIC-IV database to examine the correlation between acetaminophen use and clinical outcomes in septic patients admitted to the ICU.

Methods

We gathered pertinent data on sepsis patients from the MIMIC-IV database. We used propensity score matching (PSM) to pair acetaminophen-treated patients with those who were not treated. We then used Cox Proportional Hazards models to examine the relationships between acetaminophen use and factors such as in-hospital mortality, 30-day mortality, hospital stay duration, and ICU stay length.

Results

The data analysis involved 22,633 sepsis patients. Post PSM, a total of 15,843 patients were matched; each patient not receiving acetaminophen treatment was paired with two patients who received it. There was a correlation between acetaminophen and a lower in-hospital mortality rate (HR 0.443; 95% CI 0.371-0.530; p < 0.001) along with 30-day mortality rate (HR 0.497; 95% CI 0.424-0.583; p < 0.001). Additionally, it correlated with a decrease in the duration of hospitalization [8.4 (5.0, 14.8) vs. 9.0 (5.1, 16.0), p < 0.001] and a shorter ICU stay [2.8 (1.5, 6.0) vs. 3.1 (1.7, 6.5); p < 0.05].

Conclusion

The use of acetaminophen may lower short-term mortality in critically ill patients with sepsis. To confirm this correlation, future research should involve multicenter randomized controlled trials.

Addition of Vitamin C Does Not Decrease Neuron-Specific Enolase Levels in Adult Survivors of Cardiac Arrest-Results of a Randomized Trial

Background and Objectives: Survival with favorable neurologic outcomes after out-of-hospital cardiac arrest (OHCA) remains elusive. Post-cardiac arrest syndrome (PCAS) involves myocardial and neurological injury, ischemia-reperfusion response, and underlying pathology. Neurologic injury is a crucial determinant of survival and functional outcomes, with damage caused by free radicals among the responsible mechanisms. This study explores the feasibility of adding intravenous vitamin C to the treatment of OHCA survivors, aiming to mitigate PCAS. Vitamin C, a nutrient with antioxidative and free radical-scavenging properties, is often depleted in critically ill patients. Materials and Methods: This randomized, double-blinded trial was conducted at a tertiary-level university hospital with adult OHCA survivors. Participants received either standard care or the addition of 1.5 g of intravenous vitamin C every 12 h for eight consecutive doses. Neurologic injury was assessed using neuron-specific enolase (NSE) levels, with additional clinical and laboratory outcomes, such as enhanced neuroprognostication factors, inflammatory markers, and cardiac parameters. Results: NSE levels were non-significantly higher in patients who received vitamin C compared to the placebo group (55.05 µg/L [95% confidence interval (CI) 26.7-124.0] vs. 39.4 µg/L [95% CI 22.6-61.9], p > 0.05). Similarly, a non-significantly greater proportion of patients in the vitamin C group developed myoclonus in the first 72 h. We also observed a non-significantly shorter duration of mechanical ventilation, fewer arrhythmias, and reduced length of stay in the intensive care unit in the group of patients who received vitamin C (p = 0.031). However, caution is warranted in interpretation of our results due to the small number of participants. Conclusions: Our findings suggest that intravenous vitamin C should not be used outside of clinical trials for OHCA survivors. Due to the small sample size and conflicting results, further research is needed to determine the potential role of vitamin C in post-cardiac arrest care.

Effects of intravenous administration of ascorbic acid (vitamin C) on oxidative status in healthy adult horses

BACKGROUND

Ascorbic acid (AA) is an antioxidant that might be beneficial for adjunctive treatment of sepsis in horses. The optimal dose and effects on oxidative status are unknown.

HYPOTHESIS

Ascorbic acid administration will increase plasma AA concentrations and decrease determinants of reactive oxygen metabolites (dROM), basal and stimulant-induced intraerythrocytic reactive oxygen species (ROS) concentrations, and stimulant-induced neutrophil ROS production, and increase plasma antioxidant capacity (PAC) in a dose-dependent manner.

ANIMALS

Eight healthy horses.

METHODS

Randomized placebo-controlled crossover study. Each horse received 4 single-dose IV treatments including AA at 25, 50, and 100 mg/kg and saline (placebo) with each treatment separated by ≥1 week. Blood was collected at baseline, 2 and 6 hours for assessment of plasma dROM and PAC via photometer, intraerythrocytic ROS by flow cytometry, and stimulant-induced neutrophil ROS by a fluorometric assay. Plasma AA concentrations were measured by high-performance liquid chromatography/electrochemical detection.

RESULTS

Ascorbic acid at 100 mg/kg resulted in decreased dROM 2 hours after treatment (P = .03, 95% CI 5.51-121.2, point estimate 63.3). There was no effect of AA on basal or stimulant-induced intraerythrocytic ROS (P = .88, 95% CI -0.156 to 0.081, point estimate -0.037; P = .93, 95% CI -0.123 to 0.112, point estimate -0.006, respectively), basal or stimulant-induced neutrophil ROS (P ≥ .12, 95% CI -644.9 to 56.2, point estimate -294.4), or PAC (P ≥ .64, 95% CI -1567 to 463.4, point estimate -552.0) at any dose or timepoint. Plasma AA concentrations increased in a dose-dependent manner.

CONCLUSIONS AND CLINICAL IMPORTANCE

High-dose administration of AA might provide antioxidant benefits in horses.

The science of micronutrients in clinical practice - Report on the ESPEN symposium

BACKGROUND & AIMS

The European Society for Clinical Nutrition and Metabolism published its first clinical guidelines for use of micronutrients (MNs) in 2022. A two-day web symposium was organized in November 2022 discussing how to apply the guidelines in clinical practice. The present paper reports the main findings of this symposium.

METHODS

Current evidence was discussed, the first day being devoted to clarifying the biology underlying the guidelines, especially regarding the definition of deficiency, the impact of inflammation, and the roles in antioxidant defences and immunity. The second day focused on clinical situations with high prevalence of MN depletion and deficiency.

RESULTS

The importance of the determination of MN status in patients at risk and diagnosis of deficiencies is still insufficiently perceived, considering the essential role of MNs in immune and antioxidant defences. Epidemiological data show that deficiencies of several MNs (iron, iodine, vitamin D) are a global problem that affects human health and well-being including immune responses such as to vaccination. Clinical conditions frequently associated with MN deficiencies were discussed including cancer, obesity with impact of bariatric surgery, diseases of the gastrointestinal tract, critical illness, and aging. In all these conditions, MN deficiency is associated with worsening of outcomes. The recurrent problem of shortage of MN products, but also lack of individual MN-products is a worldwide problem.

CONCLUSION

Despite important progress in epidemiology and clinical nutrition, numerous gaps in practice persist. MN depletion and deficiency are frequently insufficiently searched for in clinical conditions, leading to inadequate treatment. The symposium concluded that more research and continued education are required to improve patient outcome.

Pediatric Sepsis Diagnosis, Management, and Sub-phenotypes

Sepsis and septic shock are major causes of morbidity, mortality, and health care costs for children worldwide, including >3 million deaths annually and, among survivors, risk for new or worsening functional impairments, including reduced quality of life, new respiratory, nutritional, or technological assistance, and recurrent severe infections. Advances in understanding sepsis pathophysiology highlight a need to update the definition and diagnostic criteria for pediatric sepsis and septic shock, whereas new data support an increasing role for automated screening algorithms and biomarker combinations to assist earlier recognition. Once sepsis or septic shock is suspected, attention to prompt initiation of broad-spectrum empiric antimicrobial therapy, fluid resuscitation, and vasoactive medications remain key components to initial management with several new and ongoing studies offering new insights into how to optimize this approach. Ultimately, a key goal is for screening to encompass as many children as possible at risk for sepsis and trigger early treatment without increasing unnecessary broad-spectrum antibiotics and preventable hospitalizations. Although the role for adjunctive treatment with corticosteroids and other metabolic therapies remains incompletely defined, ongoing studies will soon offer updated guidance for optimal use. Finally, we are increasingly moving toward an era in which precision therapeutics will bring novel strategies to improve outcomes, especially for the subset of children with sepsis-induced multiple organ dysfunction syndrome and sepsis subphenotypes for whom antibiotics, fluid, vasoactive medications, and supportive care remain insufficient.

Corticosteroids in Sepsis and Septic Shock: A Systematic Review, Pairwise, and Dose-Response Meta-Analysis

OBJECTIVES

To perform a systematic review and meta-analysis to assess the efficacy and safety of corticosteroids in patients with sepsis.

DATA SOURCES

We searched PubMed, Embase, and the Cochrane Library, up to January 10, 2023.

STUDY SELECTION

We included randomized controlled trials (RCTs) comparing corticosteroids with placebo or standard care with sepsis.

DATA EXTRACTION

The critical outcomes of interest included mortality, shock reversal, length of stay in the ICU, and adverse events.

DATA ANALYSIS

We performed both a pairwise and dose-response meta-analysis to evaluate the effect of different corticosteroid doses on outcomes. We used Grading of Recommendations Assessment, Development and Evaluation to assess certainty in pooled estimates.

DATA SYNTHESIS

We included 45 RCTs involving 9563 patients. Corticosteroids probably reduce short-term mortality (risk ratio [RR], 0.93; 95% CI, 0.88-0.99; moderate certainty) and increase shock reversal at 7 days (RR, 1.24; 95% CI, 1.11-1.38; high certainty). Corticosteroids may have no important effect on duration of ICU stay (mean difference, -0.6 fewer days; 95% CI, 1.48 fewer to 0.27 more; low certainty); however, probably increase the risk of hyperglycemia (RR, 1.13; 95% CI, 1.08-1.18; moderate certainty) and hypernatremia (RR, 1.64; 95% CI, 1.32-2.03; moderate certainty) and may increase the risk of neuromuscular weakness (RR, 1.21; 95% CI, 1.01-1.45; low certainty). The dose-response analysis showed a reduction in mortality with corticosteroids with optimal dosing of approximately 260 mg/d of hydrocortisone (RR, 0.90; 95% CI, 0.83-0.98) or equivalent.

CONCLUSIONS

We found that corticosteroids may reduce mortality and increase shock reversal but they may also increase the risk of hyperglycemia, hypernatremia, and neuromuscular weakness. The dose-response analysis indicates optimal dosing is around 260 mg/d of hydrocortisone or equivalent.

Fluid resuscitation and relation to respiratory support escalation in patients with and without pulmonary hypertension with sepsis

STUDY OBJECTIVE

To compare guideline-based fluid resuscitation and need for respiratory support escalation in septic patients with pulmonary hypertension (PH) to those without PH.

DESIGN

Single-center, retrospective cohort study.

SETTING

Tertiary care academic medical center in Detroit, Michigan.

PATIENTS

Adult patients with or without PH hospitalized and diagnosed with sepsis from November 1, 2013 through December 31, 2019. Patients with sepsis were assigned to one of two groups based on a previous PH diagnosis or no PH diagnosis.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was incidence of respiratory support escalation within 72 h from sepsis time zero. Respiratory support escalation included high-flow nasal cannula, bilevel positive airway pressure, or intubation. One-hundred and four patients were included with 52 patients in each study group. Patients with PH were more likely to require escalation of respiratory support compared to non-PH patients (32.7% vs. 11.5%; p = 0.009). Fewer patients with PH received 30 mL/kg of crystalloid within 6 h of time zero compared with non-PH patients (3.8% vs. 42.3%; p < 0.001). Vasopressor initiation was more common in patients with PH compared with the non-PH group (40.4% vs. 19.2%; p = 0.018). PH diagnosis was the only independent predictor of respiratory support escalation.

CONCLUSIONS

During initial sepsis management when compared with patients without PH, patients with PH had increased instances of respiratory support escalation within 72 h of sepsis time zero despite lower fluid resuscitation volumes.

INTRAVENOUS VITAMIN C SUPPLEMENTATION IN ALLOGENEIC HEMATOPOIETIC CELL TRANSPLANT RECIPIENTS: SALUTARY IMPACT ON CLINICAL OUTCOMES

Intravenous (IV) vitamin C improves organ function and reduces inflammation in sepsis, an inflammatory state like the post-hematopoietic stem cell transplant (SCT) milieu. The safety and efficacy of parenteral vitamin C after allogeneic hematopoietic stem cell transplant (HSCT) were evaluated in a phase I/II trial and clinical outcomes compared with a propensity score - matched historical control.

Methods

Patients with advanced hematologic malignancies were enrolled in a phase 2 clinical trial, receiving IV vitamin C, 50mg/kg/d, divided into 3 doses given on days 1-14 after HSCT, followed by 500 mg bid oral from day 15 until 6 months post-SCT.

Results

55 patients received IV vitamin C: these include 10/10 HLA-MRD and MUD (n=48) and 9/10 HLA MUD recipients (n=7). All patients enrolled were deficient in vitamin C at day 0 and had restoration to normal levels for the remainder of the course. Vitamin C recipients had lower non-relapse mortality (11% vs. 25%, p-value = 0.07) and consequently, improved survival compared to historical controls (82% vs 62% p=0.06), with no attributable grade 3 and 4 toxicities to vitamin C. Patients with myeloid malignancies had improved survival (83% vs. 54%, p=0.02) and non-relapse mortality (NRM) (10% vs. 37%, p=0.009), as well as chronic GVHD, with similar relapse rates compared to controls.

Conclusions

In patients undergoing allogeneic HSCT the administration of IV vitamin C is safe and reduces non-relapse mortality improving overall survival. Randomized trials are needed to confirm the utility of this easily available and inexpensive therapy.

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.

Targeting the host response in sepsis: current approaches and future evidence

Sepsis, a dysregulated host response to infection characterized by organ failure, is one of the leading causes of death worldwide. Disbalances of the immune response play an important role in its pathophysiology. Patients may develop simultaneously or concomitantly states of systemic or local hyperinflammation and immunosuppression. Although a variety of effective immunomodulatory treatments are generally available, attempts to inhibit or stimulate the immune system in sepsis have failed so far to improve patients' outcome. The underlying reason is likely multifaceted including failure to identify responders to a specific immune intervention and the complex pathophysiology of organ dysfunction that is not exclusively caused by immunopathology but also includes dysfunction of the coagulation system, parenchymal organs, and the endothelium. Increasing evidence suggests that stratification of the heterogeneous population of septic patients with consideration of their host response might led to treatments that are more effective. The purpose of this review is to provide an overview of current studies aimed at optimizing the many facets of host response and to discuss future perspectives for precision medicine approaches in sepsis.

Accounting for Competing Events When Evaluating Long-Term Outcomes in Survivors of Critical Illness

The clinical trajectory of survivors of critical illness after hospital discharge can be complex and highly unpredictable. Assessing long-term outcomes after critical illness can be challenging because of possible competing events, such as all-cause death during follow-up (which precludes the occurrence of an event of particular interest). In this perspective, we explore challenges and methodological implications of competing events during the assessment of long-term outcomes in survivors of critical illness. In the absence of competing events, researchers evaluating long-term outcomes commonly use the Kaplan-Meier method and the Cox proportional hazards model to analyze time-to-event (survival) data. However, traditional analytical and modeling techniques can yield biased estimates in the presence of competing events. We present different estimands of interest and the use of different analytical approaches, including changes to the outcome of interest, Fine and Gray regression models, cause-specific Cox proportional hazards models, and generalized methods (such as inverse probability weighting). Finally, we provide code and a simulated dataset to exemplify the application of the different analytical strategies in addition to overall reporting recommendations.

Intravenous vitamin C for vasoplegia: A double-blinded randomised clinical trial (VALENCIA trial)

PURPOSE

To determine whether intravenous vitamin C compared with placebo, reduces vasopressor requirements in patients with vasoplegic shock.

METHODS

Double-blinded, randomised clinical trial (RCT) conducted in two intensive care units in Perth, Australia. Vasopressor requirements at enrolment needed to be >10 μg/min noradrenaline after hypovolaemia was clinically excluded. Patients received either intravenous 1.5 g sodium ascorbate in 100 ml normal saline every 6 h for 5 days, or placebo (100 ml normal saline). The primary outcome was duration of vasopressor usage in hours. Secondary outcomes were ICU and hospital length of stay, and 28-day, ICU and hospital mortality.

RESULTS

Of the 71 patients randomised (35 vitamin C, 36 placebo group), the median vasopressor duration was 44 h [95% CI, 37-54 h] and 55 h [95% CI, 33-66 h]) in the vitamin C and placebo groups (p = 0.057). ICU and hospital length of stay, mortality outcomes were similar between groups.

CONCLUSIONS

In this RCT of patients with vasoplegic shock of at least moderate severity, the use of IV vitamin C compared with placebo did not significantly reduce the duration of vasopressors.

TRIAL REGISTRATION

Prospective registration - trial number ACTRN12617001392358.

[Laboratory and calorimetric monitoring of medical nutrition therapy in intensive and intermediate care units : Second position paper of the Section Metabolism and Nutrition of the German Interdisciplinary Association for Intensive Care and Emergency Medicine (DIVI)]

This second position paper of the Section Metabolism and Nutrition of the German Interdisciplinary Association for Intensive Care and Emergency Medicine (DIVI) provides recommendations on the laboratory monitoring of macro- and micronutrient intake as well as the use of indirect calorimetry in the context of medical nutrition therapy of critically ill adult patients. In addition, recommendations are given for disease-related or individual (level determination) substitution and (high-dose) pharmacotherapy of vitamins and trace elements.

Intravenous Vitamin C for Patients Hospitalized With COVID-19: Two Harmonized Randomized Clinical Trials

Importance

The efficacy of vitamin C for hospitalized patients with COVID-19 is uncertain.

Objective

To determine whether vitamin C improves outcomes for patients with COVID-19.

Design, Setting, and Participants

Two prospectively harmonized randomized clinical trials enrolled critically ill patients receiving organ support in intensive care units (90 sites) and patients who were not critically ill (40 sites) between July 23, 2020, and July 15, 2022, on 4 continents.

Interventions

Patients were randomized to receive vitamin C administered intravenously or control (placebo or no vitamin C) every 6 hours for 96 hours (maximum of 16 doses).

Main Outcomes and Measures

The primary outcome was a composite of organ support-free days defined as days alive and free of respiratory and cardiovascular organ support in the intensive care unit up to day 21 and survival to hospital discharge. Values ranged from -1 organ support-free days for patients experiencing in-hospital death to 22 organ support-free days for those who survived without needing organ support. The primary analysis used a bayesian cumulative logistic model. An odds ratio (OR) greater than 1 represented efficacy (improved survival, more organ support-free days, or both), an OR less than 1 represented harm, and an OR less than 1.2 represented futility.

Results

Enrollment was terminated after statistical triggers for harm and futility were met. The trials had primary outcome data for 1568 critically ill patients (1037 in the vitamin C group and 531 in the control group; median age, 60 years [IQR, 50-70 years]; 35.9% were female) and 1022 patients who were not critically ill (456 in the vitamin C group and 566 in the control group; median age, 62 years [IQR, 51-72 years]; 39.6% were female). Among critically ill patients, the median number of organ support-free days was 7 (IQR, -1 to 17 days) for the vitamin C group vs 10 (IQR, -1 to 17 days) for the control group (adjusted proportional OR, 0.88 [95% credible interval {CrI}, 0.73 to 1.06]) and the posterior probabilities were 8.6% (efficacy), 91.4% (harm), and 99.9% (futility). Among patients who were not critically ill, the median number of organ support-free days was 22 (IQR, 18 to 22 days) for the vitamin C group vs 22 (IQR, 21 to 22 days) for the control group (adjusted proportional OR, 0.80 [95% CrI, 0.60 to 1.01]) and the posterior probabilities were 2.9% (efficacy), 97.1% (harm), and greater than 99.9% (futility). Among critically ill patients, survival to hospital discharge was 61.9% (642/1037) for the vitamin C group vs 64.6% (343/531) for the control group (adjusted OR, 0.92 [95% CrI, 0.73 to 1.17]) and the posterior probability was 24.0% for efficacy. Among patients who were not critically ill, survival to hospital discharge was 85.1% (388/456) for the vitamin C group vs 86.6% (490/566) for the control group (adjusted OR, 0.86 [95% CrI, 0.61 to 1.17]) and the posterior probability was 17.8% for efficacy.

Conclusions and Relevance

In hospitalized patients with COVID-19, vitamin C had low probability of improving the primary composite outcome of organ support-free days and hospital survival.

Trial Registration

ClinicalTrials.gov Identifiers: NCT04401150 (LOVIT-COVID) and NCT02735707 (REMAP-CAP).

Causal effects of genetically vitamins and sepsis risk: a two-sample Mendelian randomization study

BACKGROUND

In recent years, observational studies have been conducted to investigate the potential impact of vitamins on sepsis. However, many of these studies have produced inconsistent results. Our Mendelian randomization (MR) study aims to evaluate the causality between vitamins and sepsis from a genetic perspective.

METHODS

Our MR study was designed following the STROBE-MR guidelines. Genetic instrumental variables for vitamins including folate, vitamin B12, B6, A (Retinol), C, D, and K were obtained from previous genome-wide association studies (GWAS) and MR studies. Five different sepsis severity levels were included in the analysis. The genetic instrumental variables were screened for potential confounders using PhenoScanner V2. MR analysis was performed using MR-egger, inverse-variance weighted multiplicative random effects (IVW-RE), inverse-variance weighted multiplicative fixed-effects (IVW-FE), and wald ratio methods to assess the relationship between vitamins and sepsis. Sensitivity analysis was performed using the MR-egger_intercept method, and the MR-PRESSO package and Cochran's Q test were used to evaluate the heterogeneity of the instrumental variables.

RESULTS

Our MR study found no statistically significant association between vitamins and sepsis risk, regardless of the type of vitamin (P-value > 0.05). The odds ratios (ORs) for folate, vitamin B6, vitamin B12, vitamin A, vitamin D, vitamin K, and vitamin C were 1.164 (95% CI: 0.895-1.514), 0.987 (95% CI: 0.969-1.005), 0.975 (95% CI: 0.914-1.041), 0.993 (95% CI: 0.797-1.238), 0.861 (95% CI: 0.522-1.42), 0.955 (95% CI: 0.86-1.059), and 1.049 (95% CI: 0.911-1.208), respectively. Similar results were observed in subgroups of different sepsis severity levels.

CONCLUSIONS

Our MR study found no evidence of a causal association between vitamins and sepsis risk from a genetic perspective. Further randomized controlled trials are necessary to confirm these results.

Micronutrient intake to protect against osteoporosis during and after critical illness

PURPOSE OF REVIEW

Improved survival from critical illness has enhanced the focus on ways to augment functional outcomes following discharge from the Intensive Care Unit. An area that is gaining increased attention is the effect of critical illness on bone health and fragility fractures following the episode. This review discusses the micronutrients that may play a role in bone metabolism and the potential benefits of their supplementation to prevent osteoporosis. These include calcium, phosphorous, magnesium, vitamin D, vitamin C, vitamin K, and certain trace elements.

FINDINGS

Although there is sound physiological basis for the involvement of these micronutrients in bone health and fracture prevention, there are few clinically relevant publications in this area with calcium and vitamin D being the best studied to date.

SUMMARY

In the absence of high-quality evidence in critically ill populations, attention to measurement and supplementation of these micronutrients as per current guidelines outlining micronutrient requirements in enteral and parenteral nutrition might mitigate bone loss and its sequelae in the recovery phase from critical illness.

Ascorbic acid modulates immune responses through Jumonji-C domain containing histone demethylases and Ten eleven translocation (TET) methylcytosine dioxygenase

Ascorbic acid is a redox regulator in many physiological processes. Besides its antioxidant activity, many intriguing functions of ascorbic acid in the expression of immunoregulatory genes have been suggested. Ascorbic acid acts as a co-factor for the Fe+2 -containing α-ketoglutarate-dependent Jumonji-C domain-containing histone demethylases (JHDM) and Ten eleven translocation (TET) methylcytosine dioxygenasemediated epigenetic modulation. By influencing JHDM and TET, ascorbic acid facilitates the differentiation of double negative (CD4- CD8- ) T cells to double positive (CD4+ CD8+ ) T cells and of T-helper cells to different effector subsets. Ascorbic acid modulates plasma cell differentiation and promotes early differentiation of hematopoietic stem cells (HSCs) to NK cells. These findings indicate that ascorbic acid plays a significant role in regulating both innate and adaptive immune cells, opening up new research areas in Immunonutrition. Being a water-soluble vitamin and a safe micro-nutrient, ascorbic acid can be used as an adjunct therapy for many disorders of the immune system.

Intravenous vitamin C therapy in adult patients with sepsis: A rapid practice guideline

BACKGROUND

This Rapid Practice Guideline provides an evidence-based recommendation to address the question: in adults with sepsis or septic shock, should we recommend using or not using intravenous vitamin C therapy?

METHODS

The panel included 21 experts from 16 countries and used a strict policy for potential financial and intellectual conflicts of interest. Methodological support was provided by the Guidelines in Intensive Care, Development, and Evaluation (GUIDE) group. Based on an updated systematic review, and the grading of recommendations, assessment, development, and evaluation approach, we evaluated the certainty of evidence and developed recommendations using the evidence-to-decision framework. We conducted an electronic vote, requiring >80% agreement among the panel for a recommendation to be adopted.

RESULTS

At longest follow-up, 90 days, intravenous vitamin C probably does not substantially impact (relative risk 1.05, 95% confidence interval [CI] 0.94 to 1.17; absolute risk difference 1.8%, 95% CI -2.2 to 6.2; 6 trials, n = 2148, moderate certainty). Effects of vitamin C on mortality at earlier timepoints was of low or very low certainty due to risk of bias of the included studies and significant heterogeneity between study results. Few adverse events were reported with the use of vitamin C. The panel did not identify any major differences in other outcomes, including duration of mechanical ventilation, ventilator free days, hospital or intensive care unit length of stay, acute kidney injury, need for renal replacement therapy. Vitamin C may result in a slight reduction in duration of vasopressor support (MD -18.9 h, 95% CI -26.5 to -11.4; 21 trials, n = 2661, low certainty); but may not reduce sequential organ failure assessment scores (MD -0.69, 95% CI -1.55 to 0.71; 24 trials, n = 4002, low certainty). The panel judged the undesirable consequences of using IV vitamin C to probably outweigh the desirable consequences, and therefore issued a conditional recommendation against using IV vitamin C therapy in sepsis.

CONCLUSIONS

The panel suggests against use of intravenous vitamin C in adult patients with sepsis, beyond that of standard nutritional supplementation. Small and single center trials on this topic should be discouraged.

HAT therapy for sepsis: A review of the therapeutic rationale and current clinical evaluation status

Vitamin C-based cluster therapy, which involves the combined application of hydrocortisone, vitamin C, and thiamine (HAT), is a recently proposed new treatment option for sepsis on top of conventional treatment. This therapy has a strong theoretical basis, but its clinical efficacy remains inconclusive. This review summarizes the rationale for HAT therapy for sepsis and describes the evaluation of its efficacy in clinical observational studies and randomized controlled trials, with the aim of providing a reference for the future clinical practice application of HAT therapy in sepsis.

Intravenous high-dose vitamin C monotherapy for sepsis and septic shock: A meta-analysis of randomized controlled trials

BACKGROUND

Vitamin C has been used as an adjuvant in the treatment of sepsis and septic shock; however, its role remains controversial. This study aimed to assess the effectiveness of intravenous high-dose vitamin C in sepsis and septic shock patients by meta-analysis.

METHODS

The PubMed, Embase, and Cochrane Library electronic databases were searched to identify relevant studies. The primary outcome was defined as the short-term all-cause mortality rate. Secondary outcomes included duration of vasoactive drug use, intensive care unit length of stay, sequential organ failure assessment scores up to 96 hours after treatment and 90-day mortality. Review Manager version 5.4 was used to perform the meta-analysis. Relative risk and mean differences (MD) with 95% confidence intervals were determined using fixed- or random-effects models.

RESULTS

Eight randomized controlled trials (RCTs) comprising 1394 patients were eligible for assessment. Overall, the pooled results showed that high-dose vitamin C decreased short-term all-cause mortality in patients with sepsis, but no significant differences were observed in patients with septic shock. Additionally, high-dose vitamin C was associated with decreased duration of vasoactive drug use in patients with sepsis, but not in patients with septic shock. However, it did not significantly affect the duration of intensive care unit stay in RCTs of patients with sepsis and septic shock. Additionally, it did not significantly affect sequential organ failure assessment scores 96 hours post-treatment or 90-day mortality.

CONCLUSION

These results suggest that intravenous high-dose vitamin C may improve outcomes in patients with sepsis, but do not benefit patients with septic shock. Further RCTs and other studies should be conducted to determine whether vitamin C should be recommended as an adjunctive sepsis treatment.

Mega-dose sodium ascorbate: a pilot, single-dose, physiological effect, double-blind, randomized, controlled trial

BACKGROUND

Mega-dose sodium ascorbate (NaAscorbate) appears beneficial in experimental sepsis. However, its physiological effects in patients with septic shock are unknown.

METHODS

We conducted a pilot, single-dose, double-blind, randomized controlled trial. We enrolled patients with septic shock within 24 h of diagnosis. We randomly assigned them to receive a single mega-dose of NaAscorbate (30 g over 1 h followed by 30 g over 5 h) or placebo (vehicle). The primary outcome was the total 24 h urine output (UO) from the beginning of the study treatment. Secondary outcomes included the time course of the progressive cumulative UO, vasopressor dose, and sequential organ failure assessment (SOFA) score.

RESULTS

We enrolled 30 patients (15 patients in each arm). The mean (95% confidence interval) total 24-h UO was 2056 (1520-2593) ml with placebo and 2948 (2181-3715) ml with NaAscorbate (mean difference 891.5, 95% confidence interval [- 2.1 to 1785.2], P = 0.051). Moreover, the progressive cumulative UO was greater over time on linear mixed modelling with NaAscorbate (P < 0.001). Vasopressor dose and SOFA score changes over time showed faster reductions with NaAscorbate (P < 0.001 and P = 0.042). The sodium level, however, increased more over time with NaAscorbate (P < 0.001). There was no statistical difference in other clinical outcomes.

CONCLUSION

In patients with septic shock, mega-dose NaAscorbate did not significantly increase cumulative 24-h UO. However, it induced a significantly greater increase in UO and a greater reduction in vasopressor dose and SOFA score over time. One episode of hypernatremia and one of hemolysis were observed in the NaAscorbate group. These findings support further cautious investigation of this novel intervention. Trial registration Australian New Zealand Clinical Trial Registry (ACTRN12620000651987), Date registered June/5/2020.

Redox regulation of defense against bacterial and viral pathogens

There is considerable interest in the role of oxygen-derived oxidants (often termed generically reactive oxygen species), and the potential effect of exogenous antioxidants, in the pathogenesis of infectious disease. Most of the published research focuses on the inflammatory response and the concept that oxidants are pro-inflammatory and antioxidants are anti-inflammatory. The present review discusses the evidence that both oxidants and thiol antioxidants are important in the various processes of innate and adaptive immunity, focusing on the function of the immune system in the defense against pathogens, rather than its pathogenic role in inflammatory and autoimmune disease.