Vitamin C-based regimens for sepsis and septic shock: Systematic review and meta-analysis of randomized clinical trials

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.

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.

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.

ESPEN practical and partially revised guideline: Clinical nutrition in the intensive care unit

Following the new ESPEN Standard Operating Procedures, the previous 2019 guideline to provide best medical nutritional therapy to critically ill patients has been shortened and partially revised. Following this update, we propose this publication as a practical guideline based on the published scientific guideline, but shortened and illustrated by flow charts. The main goal of this practical guideline is to increase understanding and allow the practitioner to implement the Nutrition in the ICU guidelines. All the items discussed in the previous guidelines are included as well as special conditions.

Effect of intravenous vitamin C on adult septic patients: a systematic review and meta-analysis

Background

An increasing number of studies indicate that vitamin C (VC) reduces the mortality of adult septic patients, while some articles suggest otherwise. We performed this systematic review and meta-analysis to resolve the discrepancies in reported results concerning the efficacy of VC in septic patients.

Methods

We comprehensively searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled trials for randomized controlled trials (RCTs) evaluating the efficacy of intravenous VC (IVVC) on adult septic patients published from inception to November 28, 2022. The quality of outcomes for eligible studies was assessed using the Recommendations Assessment, Development, and Evaluation methodology. The results were analyzed using the pooled mean difference (MD) or risk ratio (RR) and 95% confidence intervals (CIs).

Results

Twenty-two studies (3,570 adult septic patients) were included. IVVC treatment did not improve 28-day mortality compared to the control group (RR, 0.92; 95% CI, 0.81-1.04; I2 = 26%; evidence risk, moderate). IVVC monotherapy decreased mortality (RR, 0.69; 95% CI, 0.52-0.93; I2 = 57%), whereas combination therapy did not affect mortality (RR, 1.03; 95% CI, 0.90-1.17; I2 =0%). IVVC had a trend to decrease the mortality of septic patients (RR, 0.83; 95% CI, 0.69-1.00; I2 = 33%) but did not affect septic shock patients (RR, 1.01; 95% CI, 0.85-1.21; I2 = 18%). IVVC reduced the duration of vasopressor use (MD, -8.45; 95% CI, -15.43 to -1.47; evidence risk, very low) but did not influence the incidence of AKI, ICU length of stay, duration of mechanical ventilation.

Conclusions

IVVC treatment did not improve the 28-day mortality in septic patients. Subgroup analysis indicated that VC had a trend to decrease the 28-day mortality in patients with sepsis but not septic shock. IVVC monotherapy, rather than combination therapy, decreased the 28-day mortality in septic patients. The findings imply that Hydrocortisone, Ascorbic acid, Thiamine (HAT) combination therapy is not superior to IVVC monotherapy for septic patients. These findings warrant further confirmation in future studies, which should also investigate the mechanisms underlying the enhanced efficacy of IVVC monotherapy in septic patients.

Systematic review registration

https://inplasy.com/.

Vitamin C as a treatment for organ failure in sepsis

Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection, with a high morbidity and mortality rate. Exogenous vitamin C supplementation is a potential therapeutic option for the treatment of multi-organ dysfunction in sepsis due to the significantly lower levels of vitamin C in the circulating blood of sepsis patients compared to healthy subjects and the importance of vitamin C in many of the physiological processes of sepsis. Vitamin C may influence the function of numerous organs and systems, including the heart, lungs, kidneys, brain, and immune defences, by reducing oxidative stress, inhibiting inflammatory factor surges, regulating the synthesis of various mediators and hormones, and enhancing immune cell function. With the development of multiple clinical randomized controlled trials, the outcomes of vitamin C treatment for critically ill patients have been discussed anew. This review's objectives are to provide an overview of how vitamin C affects various organ functions in sepsis and to illustrate how it affects each organ. Understanding the pharmacological mechanism of vitamin C and the organ damage caused by sepsis may help to clarify the conditions and clinical applications of vitamin C.

Impact of intravenous vitamin C as a monotherapy on mortality risk in critically ill patients: A meta-analysis of randomized controlled trials with trial sequential analysis

Background

This meta-analysis aimed at investigating the pooled evidence regarding the effects of intravenous vitamin C (IVVC) on mortality rate in critically ill patients.

Methods

Databases including Medline, Embase, and Cochrane Library were searched from inception to October, 2022 to identify RCTs. The primary outcome was the risk of overall mortality. Subgroup analyses were performed based on IVVC dosage (i.e., cut-off value: 100 mg/kg/day or 10000 mg/day). Trial sequential analysis (TSA) was used to examine the robustness of evidence.

Results

A total of 12 trials including 1,712 patients were analyzed. Although meta-analysis demonstrated a lower risk of mortality in patients with IVVC treatment compared to those without [risk ratio (RR): 0.76, 95% CI: 0.6 to 0.97, p = 0.02, I2 = 36%, 1,711 patients), TSA suggested the need for more studies for verification. Moreover, subgroup analyses revealed a reduced mortality risk associated with a low IVVC dosage (RR = 0.72, p = 0.03, 546 patients), while no beneficial effect was noted with high IVVC dosage (RR = 0.74, p = 0.13, I2 = 60%, 1,165 patients). The durations of vasopressor [mean difference (MD): −37.75 h, 404 patients) and mechanical ventilation (MD: −47.29 h, 388 patients) use were shorter in the IVVC group than those in the controls, while there was no significant difference in other prognostic outcomes (e.g., length of stay in intensive care unit/hospital) between the two groups.

Conclusion

Although intravenous vitamin C as a monotherapy reduced pooled mortality, durations of vasopressor use and mechanical ventilation, further research is required to support our findings and to identify the optimal dosage of vitamin C in the critical care setting.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022371090.

The outcome of IV vitamin C therapy in patients with sepsis or septic shock: a meta-analysis of randomized controlled trials

BACKGROUND

To update a meta-analysis of randomized controlled trials (RCTs) and further explore the outcome of IV vitamin C (IVVC) administration in sepsis or septic shock patients.

METHODS

This study is a meta-analysis of RCTs. The RCTs of vitamin C therapy in sepsis or septic shock were searched in PubMed, EMBASE and Clinical Trials.gov from inception to January 16, 2023. We registered the protocol with PROSPERO (CRD42022354875). The primary outcome was delta Sequential Organ Failure Assessment (SOFA) score at 72-96 h. Two reviewers independently assessed RCTs according to eligibility criteria: (1) study type: RCT; (2) patient population: patients ≥ 18 years with sepsis or septic shock; (3) intervention: IVVC at any doses as monotherapy or combined with thiamine or and hydrocortisone compared with standard of care, no intervention or placebo (defined as control group); (4) the RCT described short-term mortality or SOFA score. Then, two authors independently extracted related information from RCTs.

RESULTS

Eighteen RCTs (n = 3364 patients) were identified in this meta-analysis. There were significant effects in the delta SOFA score from baseline to 72-96 h (MD, - 0.62; 95% CI, - 1.00 to - 0.25; p = 0.001) and the duration of vasopressor use (MD, - 15.07; 95% CI, - 21.59 to - 8.55; p < 0.00001) with IVVC therapy. Treatment with IVVC was not shown to improve short-term mortality (OR, 0.89; 95% CI, 0.77 to 1.04; p = 0.14); nevertheless, dose at 25-100 mg/kg/d subgroup associated with a significant reduction in short-term mortality (OR, 0.80; 95% CI, 0.65 to 0.97; p = 0.03). An increase adverse event was observed in IVVC therapy (OR, 1.98; 95% CI, 1.06 to 3.68; p = 0.03).

CONCLUSION

In this meta-analysis, IVVC in sepsis or septic shock patients significantly improved delta SOFA score and reduced the duration of vasopressor use, whereas it was not associated with reduction in short-term mortality and had higher adverse events.

Current role of high dose vitamin C in sepsis management: A concise review

Sepsis and septic shock are common diagnoses for patients requiring intensive care unit admission and associated with high morbidity and mortality. In addition to aggressive fluid resuscitation and antibiotic therapy, several other drugs have been tried as adjuvant therapies to reduce the inflammatory response and improve outcomes. Vitamin C has been shown to have several biological actions, including anti-inflammatory and immunomodulatory effects, which may prove beneficial in sepsis management. Initial trials showed improved patient outcomes when high dose vitamin C was used in combination with thiamine and hydrocortisone. These results, along with relative safety of high-dose (supra-physiological) vitamin C, encouraged physicians across the globe to add vitamin C as an adjuvant therapy in the management of sepsis. However, subsequent large-scale randomised control trials could not replicate these results, leaving the world divided regarding the role of vitamin C in sepsis management. Here, we discuss the rationale, safety profile, and the current clinical evidence for the use of high-dose vitamin C in the management of sepsis and septic shock.

Efficacy of Vitamin C Supplementation on Chronic Obstructive Pulmonary Disease (COPD): A Systematic Review and Meta-Analysis

Background

In recent years, the pleiotropic roles of antioxidants have drawn extensive attention in various diseases. Vitamin C is a well-known antioxidant, and it has been used to treat patients with chronic obstructive pulmonary disease (COPD). This systematic review and meta-analysis aim to demonstrate the impact of vitamin C supplementation in patients with COPD.

Methods

We searched PubMed, Embase, Cochrane Library, Web of Science, Chinese National Knowledge Infrastructure (CNKI), SinoMed, Wanfang, and China Science and Technology Journal Database (cqvip.com) for eligible randomized controlled trials (RCTs) from their respective inception to May 18^th, 2021, by using the searching terms of COPD, vitamin C, and RCTs. A meta-analysis was performed to evaluate the effects of vitamin C on lung function, antioxidant levels, and nutritional conditions in COPD patients by using Review Manager (Version 5.4).

Results

Ten RCTs including 487 participants were eligible for our study. Meta-analysis results showed that vitamin C supplementation (≥400 mg/day) can significantly improve the forced expiratory volume in one second as a percentage (FEV1%) in COPD (SMD:1.08, 95% CI:0.03, 2.12, P=0.04). Moreover, vitamin C supplementation significantly improved the ratio of forced expiratory volume in 1 second and forced vital capacity (FEV1/FVC) (WMD:0.66, 95% CI: 0.26, 1.06, P=0.001), vitamin C level in serum (SMD:0.63, 95% CI: 0.02, 1.24, P=0.04) and glutathione (GSH) level in serum (SMD:2.47, 95% CI: 1.06, 3.89, P=0.0006). While no statistically significant difference was observed in body mass index (BMI), fat-free mass index (FFMI), vitamin E level and superoxide dismutase (SOD) level in serum.

Conclusion

Vitamin C supplementation could increase the levels of antioxidation in serum (vitamin C and GSH) and improve lung function (FEV1% and FEV1/FVC), especially in patients treated with vitamin C supplementation greater than 400 mg/day. However, further prospective studies are needed to explore the role of vitamin C in improving nutritional status.