Efficacy and Safety of Parenteral High-Dose Vitamin C Therapy in Pediatric Patients: A Scoping Review

Resuscitation in Paediatric Septic Shock Using Vitamin C and Hydrocortisone (RESPOND): The RESPOND Randomized Controlled Trial Protocol

OBJECTIVES

Pediatric sepsis results in significant morbidity and mortality worldwide. There is an urgent need to investigate adjunctive therapies that can be administered early. We hypothesize that using vitamin C combined with hydrocortisone increases survival free of inotropes/vasopressors support until day 7 compared with standard care. Here we describe the Resuscitation in Paediatric Septic Shock using Vitamin C and Hydrocortisone (RESPOND) trial protocol, which aims to address this hypothesis.

DESIGN

Randomized, open label, controlled, parallel-group, three-arm trial with integrated economic evaluation.

SETTING

Nine Australia and New Zealand PICUs, with interest from additional international sites.

PATIENTS

Children between 7 days and younger than 18 years old who are treated for suspected or confirmed sepsis and receiving inotropes/vasopressors for greater than 1 hour.

INTERVENTIONS

IV vitamin C (100 mg/kg [maximum 5 g] every 6 hr) and hydrocortisone (1 mg/kg [maximum 50 mg] every 6 hr), or IV hydrocortisone alone (1 mg/kg [maximum 50 mg] every 6 hr) or standard care.

MEASUREMENTS AND MAIN RESULTS

Three hundred eighty-four children will be randomly assigned to receive the interventions, or standard care in a 1:1:1 ratio with stratification by steroid administration pre-randomization and hospital site. The primary outcome is time alive and free of inotropes/vasopressors, censored at 7 days. Secondary outcomes include 28-day mortality, survival free of organ support, PICU length of stay, quality of life, functional status and neurodevelopmental vulnerability at 6 months post-enrollment, and hospitalization-related costs. Statistical analysis will be based on an intention-to-treat principle. The study has ethical approval (HREC/20/QCHQ/69922, dated December 21, 2020), is registered in the Australian New Zealand Clinical Trials Registry (ACTRN12621000247875), commenced recruitment on December 8, 2021, and is expected to finish recruitment by mid-2026.

CONCLUSIONS

Dissemination of the results will occur through publication in peer-reviewed journals, presentations at international conferences, and additional consumer-informed pathways.

Evaluation of Parenteral Vitamin C's Effectiveness in Critically Ill Patients: A Systematic Review and Critical Appraisal

Vitamin C, a key nutrient with potent antioxidant and immunomodulatory properties, has been explored for its therapeutic potential in treating severe infections, particularly sepsis. This systematic review aims to evaluate the effectiveness of parenteral vitamin C in improving clinical outcomes in patients with severe infections. A comprehensive search of several databases, including PubMed, EMBASE, and the Cochrane Library, was conducted for studies published between January 2000 and June 2024. Included were randomized controlled trials, observational studies, and case reports that examined the use of parenteral vitamin C in adult patients with severe infections. Data extracted included study design, sample size, intervention specifics, and clinical outcomes. Quality was assessed using tools appropriate to each study design, such as the Cochrane Risk of Bias Tool and the Newcastle-Ottawa Scale. The review included nine studies with diverse methodologies. While individual studies reported benefits such as improved immune function and reduced oxidative stress, larger systematic reviews and meta-analyses did not demonstrate a significant reduction in mortality. The results indicate that while parenteral vitamin C may improve certain biochemical and physiological parameters, these improvements do not consistently translate into enhanced survival or substantial clinical benefits. Parenteral vitamin C shows potential in modulating immune response and reducing oxidative damage in severe infections. However, its impact on key clinical outcomes like mortality and long-term recovery remains uncertain. This review highlights the need for further high-quality, randomized controlled trials to clarify vitamin C's role in managing severe infections and define optimal therapeutic protocols.

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.

Serum Levels of Vitamin C and Thiamin in Children With Suspected Sepsis: A Prospective Observational Cohort Study

OBJECTIVES

Vitamin C and thiamin have been trialed as adjunctive therapies in adults with septic shock but their role in critically ill children is unclear. We assessed serum levels of vitamin C and thiamin in children evaluated for sepsis.

DESIGN

Single-center prospective observational study. Serum levels of vitamin C and thiamin were measured on admission and association with multiple organ dysfunction syndrome (MODS) was explored using logistic regression.

SETTING

Emergency department and PICU in a tertiary children's hospital, Queensland, Australia.

PATIENTS

Children greater than 1 month and less than 17 years evaluated for sepsis.

INTERVENTIONS

Not applicable.

MEASUREMENTS AND MAIN RESULTS

Vitamin levels were determined in 221 children with a median age of 3.5 (interquartile range [IQR] 1.6, 8.3) years. Vitamin C levels were inversely correlated with severity as measured by pediatric Sequential Organ Failure Assessment (Spearman's rho = -0.16, p = 0.018). Median (IQR) vitamin C levels on admission were 35.7 (17.9, 54.1) µmol/L, 36.1 (21.4, 53.7) µmol/L, and 17.9 (6.6, 43.0) µmol/L in children without organ dysfunction, single organ dysfunction, and MODS, respectively (p = 0.017). In multivariable analyses, low levels of vitamin C at the time of sampling were associated with greater odds of MODS (adjusted odds ratio [aOR] 3.04; 95% CI, 1.51-6.12), and vitamin C deficiency was associated with greater odds of MODS at 24 hours after sampling (aOR 3.38; 95% CI, 1.53-7.47). Median (IQR) thiamin levels were 162 (138, 192) nmol/L, 185 (143, 200) nmol/L, and 136 (110, 179) nmol/L in children without organ dysfunction, single organ dysfunction, and MODS, respectively (p = 0.061). We failed to identify an association between thiamin deficiency and either MODS at sampling (OR 2.52; 95% CI, 0.15-40.86) or MODS at 24 hours (OR 2.96; 95% CI, 0.18-48.18).

CONCLUSIONS

Critically ill children evaluated for sepsis frequently manifest decreased levels of vitamin C, with lower levels associated with higher severity.

Scurvy: A treatable forgotten fatal differential diagnosis and potential etiology of leukemia and aplastic anemia in pediatric population

Scurvy is a rare nutritional deficiency disease which is less likely to be suspected and it mostly lead to delayed diagnosis. It can present with features which can mislead clinicians to misdiagnose the condition as leukemia or aplastic anemia. This can subject patients to the wrong management which leads to poor outcome and increased preventable morbidity and mortality. Vitamin C deficiency is still prevalent among pediatric population even in the modern days and should no longer be considered as historical condition. Chromosomal fragility has been greatly accounted for the development of leukemia and aplastic anemia secondary to various triggers. The role of vitamin C toward DNA stability, prevention, and control of mutations have been documented. Vitamin C plays a vital role in hematopoiesis by controlling regulation and prevent dysfunction of hematopoietic stem cells. Scurvy deficiency has been a silent growing clinical problem which needs a high index of suspicion for a clinician to pick it. It should be considered as one among potential differential diagnosis of leukemia and aplastic anemia especially in the pediatric population. History of any dietary restriction should be obtained and addressed properly. Serum vitamin C should be among the essential laboratory workout in diagnosis of both leukemia and aplastic anemia. All patients suspected to have such conditions should be screened and supplemented for vitamin C deficiency irrespective of positive confirmatory test results of leukemia or aplastic anemia since the probability of co-occurrence is likely also. Moreover, studies should be conducted to explore the clinical link, if any, between vitamin C deficiency or insufficiency and development of leukemia and aplastic anemia among the pediatric population given its physiological and genomic role in hematopoiesis. Furthermore, the potential pharmacological therapeutic use of vitamin C in treatment of leukemia and aplastic anemia should be determined clinically.

Risk of Hypovitaminosis and Vitamin C Deficiency in Pediatric Patients Undergoing Cardiopulmonary Bypass

Vitamin C levels are known rapidly decrease in adult critical illness. Vitamin C scavenges free radicals, provides critical protection of the endothelial barrier, and improves endothelial responsiveness to catecholamines. Children with congenital heart disease and undergoing cardiac surgery might be at increased risk for low circulating vitamin C levels. A prospective single-center observational study investigated perioperative changes in vitamin C levels in critically ill Children who underwent congenital heart surgery using CPB. Vitamin C serum levels were collected preoperatively and postoperatively (upon admission to the ICU, 24 and 72 h). Linear mixed-effect model was used to estimate mean circulating concentration of vitamin C and to estimate changes in concentration over time. Primary outcome was change in circulating levels of vitamin C before and after CPB. Secondary outcomes were hospital length of stay (LOS), acute kidney injury (AKI), and illness severity. Forty-one patients with a median age of 4.5 [interquartile range (IQR) 2.6-65.6] months at the time of surgery were consented and enrolled. Median CPB duration was 130 [90-175] minutes, and hospital LOS was 9.1 [5.2-19] days. Mean vitamin C levels (μmol/L) before CPB, at PICU admission, 24 h, and 72 h were 82.0 (95% CI 73.4-90.7), 53.4 (95% CI 44.6,62.0), 55.1 (95% CI 46.3,63.8), and 59.2 (95% CI 50.3,68.1), respectively. Upon postoperative admission to the PICU, vitamin C levels decreased by 28.7 (95% CI 20.6-36.8; p < 0.001) μmol/L, whereas levels at 24 and 72 h recovered and did not differ substantially from concentrations reported upon PICU admission (p > 0.15). Changes in vitamin C concentration were not associated with CPB time, STAT mortality category, age, or PIM3. Three patients had post-CPB hypovitaminosis C or vitamin C deficiency. Reduction in vitamin C levels was not associated with hospital LOS (p = 0.673). A 25 μmol/L decrease in vitamin C levels upon PICU admission was associated with developing AKI (aOR = 3.65; 95% CI 1.01-18.0, p = 0.049). Pediatric patients undergoing cardiac surgery with CPB showed decreased vitamin C levels during the immediate postoperative period. Effects of hypovitaminosis C and vitamin C deficiency in this population remain unclear.

Vitamin C Deficiency in Critically Ill Children: Prospective Observational Cohort Study

OBJECTIVES

To evaluate the presence of vitamin C deficiency in critically ill children admitted to the PICU.

DESIGN

Single-center prospective observational cohort study.

SETTING

A 28-bed PICU and a pediatric outpatient sedation room of a tertiary-care teaching hospital.

PATIENTS

Two pediatric patient groups 0-21 years old were studied: a PICU group and a group receiving deep sedation for elective outpatient procedures (noncritical care group).

INTERVENTIONS

Vitamin C level was drawn for the PICU group within 24 hours of admission. Vitamin C level was drawn prior to start of deep sedation for the noncritical group.

MEASUREMENT AND MAIN RESULTS

Vitamin C deficiency was present in 11/60 (18%) in the PICU group and 0/21 (0%) of the noncritical group (p < 0.05).

CONCLUSIONS

Vitamin C deficiency was prevalent in our patients admitted to PICU.

Serum Ascorbic Acid and Thiamine Concentrations in Sepsis: Secondary Analysis of the Swiss Pediatric Sepsis Study

OBJECTIVES

To determine circulating levels of ascorbic acid (VitC) and thiamine (VitB1) in neonates and children with blood culture-proven sepsis.

DESIGN

Nested single-center study of neonates and children prospectively included in the Swiss Pediatric Sepsis Study.

SETTING

One tertiary care academic hospital.

PATIENTS

Sixty-one neonates and children 0-16 years old.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

VitC and VitB1 were quantified in serum of patients (median age, 10.5 mo; interquartile range [IQR], 0.5-62.1 mo) with blood culture-proven sepsis. Median time between sepsis onset and sampling for measurement of vitamins was 3 days (IQR, 2-4 d). Median serum levels of VitC and VitB1 were 32.4 μmol/L (18.9-53.3 μmol/L) and 22.5 nmol/L (12.6-82 nmol/L); 36% of the patients (22/61) had low VitC and 10% (6/61) had VitC deficiency; and 72% (44/61) had low VitB1 and 13% (8/61) had VitB1 deficiency. Children with low VitC were older (p = 0.007) and had higher C-reactive protein (p = 0.004) compared with children with VitC within the normal range. Children with low VitB1 levels were older (p = 0.0009) and were less frequently receiving enteral or parenteral vitamin supplementation (p = 0.0000003) compared with children with normal VitB1 levels.

CONCLUSIONS

In this cohort of newborns and children with sepsis, low and deficient VitC and VitB1 levels were frequently observed. Age, systemic inflammation, and vitamin supplementation were associated with vitamin levels during sepsis.

Metabolic resuscitation in pediatric sepsis: a narrative review

Sepsis, defined as infection with associated organ dysfunction, accounts for most childhood deaths due to infection globally. Evidence for the optimal support of children with septic shock refractory to the initial sepsis management bundle remains minimal. There is an urgent need for more effective interventions. Administration of hydrocortisone in children with septic shock might fasten shock resolution, and has been shown to dampen the systemic host immune response, augment adrenergic effects, and support the stress response. Ascorbic acid (vitamin C) is one of the most powerful naturally occurring antioxidants and has beneficial effects on multiple pathways which are severely deranged during septic shock. A regimen combining hydrocortisone, ascorbic acid, and thiamine termed "metabolic resuscitation" or "HAT therapy" has been tested in large trials in critically ill adults with sepsis with conflicting results. Available information on intravenous ascorbic acid indicates an excellent safety profile even at very high doses both in adults and children. Given the pharmacological properties and beneficial effects shown both in vitro and in animal studies, and its safety profile, ascorbic acid either as a single therapy or as part of HAT treatment represents a promising candidate for future pediatric sepsis treatments. While pediatric age groups may be more susceptible to ascorbic acid deficiency during sepsis, there is a lack of high-quality trial data on HAT therapy in this age group. A single centre retrospective study identified potential for mortality benefit in children with septic shock, and the results from a randomized controlled pilot trial are being awaited. It is imperative for pediatric research on ascorbic acid and HAT in children with sepsis to critically investigate key questions related to pharmacology, dosing, timing, feasibility, safety, effects on short- and long-term outcomes, and generalisability in view of the global burden of sepsis.

Resuscitation in Paediatric Sepsis Using Metabolic Resuscitation-A Randomized Controlled Pilot Study in the Paediatric Intensive Care Unit (RESPOND PICU): Study Protocol and Analysis Plan

Introduction: Septic shock remains amongst the leading causes of childhood mortality. Therapeutic options to support children with septic shock refractory to initial resuscitation with fluids and inotropes are limited. Recently, the combination of intravenous hydrocortisone with high dose ascorbic acid and thiamine (HAT therapy), postulated to reduce sepsis-related organ dysfunction, has been proposed as a safe approach with potential for mortality benefit, but randomized trials in paediatric patients are lacking. We hypothesize that protocolised early use of HAT therapy ("metabolic resuscitation") in children with septic shock is feasible and will lead to earlier resolution of organ dysfunction. Here, we describe the protocol of the Resuscitation in Paediatric Sepsis Using Metabolic Resuscitation-A Randomized Controlled Pilot Study in the Paediatric Intensive Care Unit (RESPOND PICU). Methods and Analysis: The RESPOND PICU study is an open label randomized-controlled, two-sided multicentre pilot study conducted in paediatric intensive care units (PICUs) in Australia and New Zealand. Sixty children aged between 28 days and 18 years treated with inotropes for presumed septic shock will be randomized in a 1:1 ratio to either metabolic resuscitation (1 mg/kg hydrocortisone q6h, 30 mg/kg ascorbic acid q6h, 4 mg/kg thiamine q12h) or standard septic shock management. Main outcomes include feasibility of the study protocol and survival free of organ dysfunction censored at 28 days. The study cohort will be followed up at 28-days and 6-months post enrolment to assess neurodevelopment, quality of life and functional status. Biobanking will allow ancillary studies on sepsis biomarkers. Ethics and Dissemination: The study received ethical clearance from Children's Health Queensland Human Research Ethics Committee (HREC/18/QCHQ/49168) and commenced enrolment on June 12th, 2019. The primary study findings will be submitted for publication in a peer-reviewed journal. Trial Registration: Australian and New Zealand Clinical Trials Registry (ACTRN12619000829112). Protocol Version: V1.8 22/7/20.