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.

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.

Relationship of blood thiamine pyrophosphate to plasma phosphate and the response to enteral nutrition plus co-administration of intravenous thiamine during critical illness.

BACKGROUND: Hypovitamin B1 occurs frequently during critical illness but is challenging to predict or rapidly diagnose. The aim of this study was to evaluate whether plasma phosphate concentrations predict hypovitamin B1, enteral nutrition prevents hypovitamin B1 and intravenous thiamine supplementation achieves supraphysiological concentrations in critically ill patients. METHODS: Thirty-two enterally fed critically ill patients, with a plasma phosphate concentration ≤0.65 mmol/L, formed a nested cohort within a larger randomised clinical trial. Patients were assigned to receive intravenous thiamine (200 mg) twice daily, and controls were not administered intravenous thiamine. Thiamine pyrophosphate concentrations were measured at four time points (pre- and post-infusion and 4- and 6-h post-infusion) on days 1 and 3 in those allocated to thiamine and once in the control group. RESULTS: Baseline thiamine pyrophosphate concentrations were similar (intervention 88 [67, 93] vs. control 89 [62, 110] nmol/L, p = 0.49). Eight (25%) patients had hypovitamin B1 (intervention 3 vs. control 5), with two patients in the control group remaining insufficient at day 3. There was no association between baseline phosphate and thiamine pyrophosphate concentrations. Intravenous thiamine achieved supraphysiological concentrations 6 h post first infusion, with concentrations increasing to day 3. In the control group, thiamine pyrophosphate concentrations were not statistically different between baseline and day 3 (mean change: 8.6 [-6.0, 23.1] nmol/L, p = 0.25). CONCLUSIONS: Phosphate concentrations did not predict hypovitamin B1, which was observed in 25% of the participants. Enteral nutrition alone prevented the development of new hypovitamin B1. Administration of a single 200-mg dose of intravenous thiamine achieved supraphysiological concentrations of thiamine pyrophosphate, with repeated dosing sustaining this effect.

Update on vitamin C administration in critical illness.

PURPOSE OF REVIEW: Several studies have recently explored the effects of intravenous vitamin C in sepsis. We aimed to summarize their findings to provide perspectives for future research. RECENT FINDINGS: Sepsis trials examined 6 g/day of intravenous vitamin C with or without the thiamine and/or hydrocortisone compared with placebo or hydrocortisone. Network meta-analysis reported that intravenous vitamin C, thiamine, hydrocortisone, or combinations of these drugs was not proven to reduce long-term mortality. However, the component network meta-analysis suggested an association of high-dose (>6 g/day) and very-high dose vitamin C (>12 g/day) and decreased mortality but with low certainty. The preclinical investigations have, however, advanced to much higher doses of intravenous vitamin C therapy since a scoping review on harm reported that mega-doses of intravenous vitamin C (50-100 g/day) had been administered without any conclusive adverse effects. In a Gram-negative sheep model, renal tissue hypoperfusion was reversed, followed by improvements in kidney function when a mega-dose of vitamin C (150 g/day equivalent) was administered. SUMMARY: The effect of intravenous vitamin C in critically ill patients has yet to be determined and might be dose-dependent. Clinical studies of very high or mega doses of vitamin C are justified by preclinical data.

Effect of adjunctive vitamin C, glucocorticoids, and vitamin B1 on longer-term mortality in adults with sepsis or septic shock: a systematic review and a component network meta-analysis.

We aimed to compare the effects of vitamin C, glucocorticoids, vitamin B1, combinations of these drugs, and placebo or usual care on longer-term mortality in adults with sepsis or septic shock. MEDLINE, Embase, CENTRAL, ClinicalTrials.gov and WHO-ICTRP were searched. The final search was carried out on September 3rd, 2021. Multiple reviewers independently selected randomized controlled trials (RCTs) comparing very-high-dose vitamin C (≥ 12 g/day), high-dose vitamin C (< 12, ≥ 6 g/day), vitamin C (< 6 g/day), glucocorticoid (< 400 mg/day of hydrocortisone), vitamin B1, combinations of these drugs, and placebo/usual care. We performed random-effects network meta-analysis and, where applicable, a random-effects component network meta-analysis. We used the Confidence in Network Meta-Analysis framework to assess the degree of treatment effect certainty. The primary outcome was longer-term mortality (90-days to 1-year). Secondary outcomes were severity of organ dysfunction over 72 h, time to cessation of vasopressor therapy, and length of stay in intensive care unit (ICU). Forty-three RCTs (10,257 patients) were eligible. There were no significant differences in longer-term mortality between treatments and placebo/usual care or between treatments (10 RCTs, 7,096 patients, moderate to very-low-certainty). We did not find any evidence that vitamin C or B1 affect organ dysfunction or ICU length of stay. Adding glucocorticoid to other treatments shortened duration of vasopressor therapy (incremental mean difference, - 29.8 h [95% CI - 44.1 to - 15.5]) and ICU stay (incremental mean difference, - 1.3 days [95% CI - 2.2 to - 0.3]). Metabolic resuscitation with vitamin C, glucocorticoids, vitamin B1, or combinations of these drugs was not significantly associated with a decrease in longer-term mortality.

Therapeutic potential of megadose vitamin C to reverse organ dysfunction in sepsis and COVID-19.

Sepsis induced by bacteria or viruses can result in multiorgan dysfunction, which is a major cause of death in intensive care units. Current treatments are only supportive, and there are no treatments that reverse the pathophysiological effects of sepsis. Vitamin C has antioxidant, anti-inflammatory, anticoagulant and immune modulatory actions, so it is a rational treatment for sepsis. Here, we summarise data that support the use of megadose vitamin C as a treatment for sepsis and COVID-19. Megadose intravenous sodium ascorbate (150 g per 40 kg over 7 h) dramatically improved the clinical state and cardiovascular, pulmonary, hepatic and renal function and decreased body temperature, in a clinically relevant ovine model of Gram-negative bacteria-induced sepsis. In a critically ill COVID-19 patient, intravenous sodium ascorbate (60 g) restored arterial pressure, improved renal function and increased arterial blood oxygen levels. These findings suggest that megadose vitamin C should be trialled as a treatment for sepsis and COVID-19.

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.

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

OBJECTIVES: Recently, several adult trials have investigated the potential benefit of high-dose vitamin C therapy in critically ill patients. In pediatric patients, little is known on the efficacy, safety, and risk of high-dose vitamin C therapy. We aimed to review the efficacy and potential harm associated with high-dose vitamin C treatment. DATA SOURCES: We searched MEDLINE, EMBASE, Cochrane Library, and National Institute of Health Clinical Trials Register. STUDY SELECTION: We included studies in neonatal and pediatric patients who received IV or intra-arterial high-dose vitamin C (ascorbic acid) defined as greater than or equal to 75 mg/kg/d. DATA EXTRACTION: Two independent investigators screened articles and extracted data. DATA SYNTHESIS: We found 1,364 articles, assessed 193 full texts for eligibility, and identified 12 eligible studies. These studies included 855 patients, with 194 receiving high-dose vitamin C. The age of patients who received high-dose vitamin C ranged from 2 hours after delivery to 8.4 years (median 2.4 yr), and the vitamin C dose ranged from 100 to 1,500 mg/kg/d (median 260.5 mg/kg/d). Four studies were double-blind randomized controlled trials, and no clinical efficacy outcome was reported in favor of or against vitamin C. Furthermore, no adverse event or signal of harm was reported with high-dose vitamin C. CONCLUSIONS: In 12 studies with 194 children treated with parenteral high-dose vitamin C, there was no evidence of clinical efficacy or inferior clinical outcomes in double-blind randomized controlled trials, and no reported harmful effects. These findings justify further investigations of this treatment in children.

Zinc supplementation as an adjunct therapy for COVID-19: Challenges and opportunities.

An outbreak of a novel coronavirus (COVID-19 or 2019-CoV) infection has posed significant threats to international health and the economy. Patients with COVID-19 are at risk of cytokine storm, acute respiratory distress syndrome (ARDS), reduced blood oxygenation, mechanical ventilation, and a high death rate. Although recent studies have shown remdesivir and dexamethasone as treatment options, there is an urgent need to find a treatment to inhibit virus replication and to control the progression of the disease. Essential biometal zinc has generated a lot of excitement as one of the promising candidates to reduce the severity of COVID-19 infection. Several published observations outlined in the review are the reasons why there is a global enthusiasm that zinc therapy could be a possible therapeutic option. However, the biggest challenge in realising the therapeutic value of zinc is lack of optimal treatment modalities such as dose, duration of zinc supplementation and the mode of delivery. In this review, we discuss the regulatory mechanism that hinges upon the bioavailability of zinc. Finally, we propose that intravenous zinc could circumvent the confounding factors affecting the bioavailability of zinc and allow zinc to achieve its therapeutic potential. If successful, due to advantages such as lack of toxicity, low cost and ease of availability, intravenous zinc could be rapidly implemented clinically.

A pilot double-blind safety and feasibility randomized controlled trial of high-dose intravenous zinc in hospitalized COVID-19 patients.

Zinc inhibits replication of the SARS-CoV virus. We aimed to evaluate the safety, feasibility, and biological effect of administering high-dose intravenous zinc (HDIVZn) to patients with COVID-19. We performed a Phase IIa double-blind, randomized controlled trial to compare HDIVZn to placebo in hospitalized patients with COVID-19. We administered trial treatment per day for a maximum of 7 days until either death or hospital discharge. We measured zinc concentration at baseline and during treatment and observed patients for any significant side effects. For eligible patients, we randomized and administered treatment to 33 adult participants to either HDIVZn (n = 15) or placebo (n = 18). We observed no serious adverse events throughout the study for a total of 94 HDIVZn administrations. However, three participants in the HDIVZn group reported infusion site irritation. Mean serum zinc on Day 1 in the placebo, and the HDIVZn group was 6.9 ± 1.1 and 7.7 ± 1.6 µmol/l, respectively, consistent with zinc deficiency. HDIVZn, but not placebo, increased serum zinc levels above the deficiency cutoff of 10.7 µmol/l (p < .001) on Day 6. Our study did not reach its target enrollment because stringent public health measures markedly reduced patient hospitalizations. Hospitalized COVID-19 patients demonstrated zinc deficiency. This can be corrected with HDIVZn. Such treatment appears safe, feasible, and only associated with minimal peripheral infusion site irritation. This pilot study justifies further investigation of this treatment in COVID-19 patients.

Reversal of the Pathophysiological Responses to Gram-Negative Sepsis by Megadose Vitamin C.

OBJECTIVES: Oxidative stress appears to initiate organ failure in sepsis, justifying treatment with antioxidants such as vitamin C at megadoses. We have therefore investigated the safety and efficacy of megadose sodium ascorbate in sepsis. DESIGN: Interventional study. SETTING: Research Institute. SUBJECTS: Adult Merino ewes. INTERVENTIONS: Sheep were instrumented with pulmonary and renal artery flow-probes, and laser-Doppler and oxygen-sensing probes in the kidney. Conscious sheep received an infusion of live Escherichia coli for 31 hours. At 23.5 hours of sepsis, sheep received fluid resuscitation (30 mL/kg, Hartmann solution) and were randomized to IV sodium ascorbate (0.5 g/kg over 0.5 hr + 0.5 g/kg/hr for 6.5 hr; n = 5) or vehicle (n = 5). Norepinephrine was titrated to restore mean arterial pressure to baseline values (~80 mm Hg). MEASUREMENTS AND MAIN RESULTS: Sepsis-induced fever (41.4 ± 0.2°C; mean ± se), tachycardia (141 ± 2 beats/min), and a marked deterioration in clinical condition in all cases. Mean arterial pressure (86 ± 1 to 67 ± 2 mm Hg), arterial Po2 (102.1 ± 3.3 to 80.5 ± 3.4 mm Hg), and renal medullary tissue Po2 (41 ± 5 to 24 ± 2 mm Hg) decreased, and plasma creatinine doubled (71 ± 2 to 144 ± 15 µmol/L) (all p < 0.01). Direct observation indicated that in all animals, sodium ascorbate dramatically improved the clinical state, from malaise and lethargy to a responsive, alert state within 3 hours. Body temperature (39.3 ± 0.3°C), heart rate (99.7 ± 3 beats/min), and plasma creatinine (32.6 ± 5.8 µmol/L) all decreased. Arterial (96.5 ± 2.5 mm Hg) and renal medullary Po2 (48 ± 5 mm Hg) increased. The norepinephrine dose was decreased, to zero in four of five sheep, whereas mean arterial pressure increased (to 83 ± 2 mm Hg). We confirmed these physiologic findings in a coronavirus disease 2019 patient with shock by compassionate use of 60 g of sodium ascorbate over 7 hours. CONCLUSIONS: IV megadose sodium ascorbate reversed the pathophysiological and behavioral responses to Gram-negative sepsis without adverse side effects. Clinical studies are required to determine if such a dose has similar benefits in septic patients.

Randomised controlled trial for high-dose intravenous zinc as adjunctive therapy in SARS-CoV-2 (COVID-19) positive critically ill patients: trial protocol.

INTRODUCTION: SARS-CoV-2 (COVID-19) has caused an international pandemic of respiratory illness, resulting in significant healthcare and economic turmoil. To date, no robust vaccine or treatment has been identified. Elemental zinc has previously been demonstrated to have beneficial effects on coronaviruses and other viral respiratory infections due to its effect on RNA polymerase. Additionally, zinc has well-demonstrated protective effects against hypoxic injury-a clear mechanism of end-organ injury in respiratory distress syndrome. We aimed to assess the effect of high-dose intravenous zinc (HDIVZn) on SARS-CoV-2 infection. The end of study analyses will evaluate the reduction of impact of oxygen saturations or requirement of oxygen supplementation. METHODS AND ANALYSIS: We designed a double-blind randomised controlled trial of daily HDIVZn (0.5 mg/kg) versus placebo. Primary outcome measures are lowest oxygen saturation (or greatest level of supplemental oxygenation) for non-ventilated patients and worst PaO2/FiO2 for ventilated patients. Following power calculations, 60 hospitalised patients and 100 ventilated patients will be recruited to demonstrate a 20% difference. The duration of follow-up is up to the point of discharge. ETHICS AND DISSEMINATION: Ethical approval was obtained through the independent Human Research Ethics Committee. Participant recruitment will commence in May 2020. Results will be published in peer-reviewed medical journals. TRIAL REGISTRATION NUMBER: ACTRN126200000454976.

Harm of IV High-Dose Vitamin C Therapy in Adult Patients: A Scoping Review.

OBJECTIVES: The potential harm associated with the use of IV vitamin C has not been systematically assessed. We aimed to review the available evidence on harm related to such treatment. DATA SOURCES: We searched MEDLINE, EMBASE, Cochrane Library, National Institute of Health Clinical Trials Register, and World Health Organization International Clinical Trials Registry Platform. STUDY SELECTION: We included studies in adult population that reported harm related to IV high-dose vitamin C which we defined as greater than or equal to 6 g/d, greater than or equal to 75 mg/kg/d, or greater than or equal to 3 g/m/d. DATA EXTRACTION: Two independent investigators screened records and extracted data. DATA SYNTHESIS: We identified 8,149 reports, of which 650 full text were assessed for eligibility, leaving 74 eligible studies. In these studies, 2,801 participants received high-dose vitamin C at a median (interquartile range) dose of 22.5 g/d (8.25-63.75 g/d), 455 mg/kg/d (260-925 mg/kg/d), or 70 g/m/d (50-90 g/m/d); and 932 or more adverse events were reported. Among nine double-blind randomized controlled trials (2,310 patients), adverse events were reported in three studies with an event rate per patient for high-dose vitamin C identical to placebo group in one study (0.1 [1/10] vs 0.1 [1/10]), numerically lower in one study (0.80 [672/839] vs 0.82 [709/869]), and numerically higher in one study (0.33 [24/73] vs 0.23 [17/74]). Six double-blind randomized controlled trials reported no adverse event in either group. Five cases of oxalate nephropathy, five cases of hypernatremia, three cases of hemolysis in glucose-6-phosphate dehydrogenase deficiency patients, two cases of glucometer error, and one case of kidney stones were also reported overall. CONCLUSIONS: There is no consistent evidence that IV high-dose vitamin C therapy is more harmful than placebo in double-blind randomized controlled trials. However, reports of oxalate nephropathy, hypernatremia, glucometer error, and hemolysis in glucose-6-phosphate dehydrogenase deficiency patients warrant specific monitoring.

A Pilot, Double-Blind, Randomized, Controlled Trial of High-Dose Intravenous Vitamin C for Vasoplegia After Cardiac Surgery.

OBJECTIVE: To conduct a pilot feasibility and physiologic efficacy study of high-dose vitamin C in patients with vasoplegia after cardiac surgery. DESIGN: Prospective, double-blind, randomized, controlled trial. SETTING: Two tertiary intensive care units (ICUs). PARTICIPANTS: Post-cardiac surgery patients with vasoplegia. INTERVENTIONS: The authors randomly assigned the patients to receive either high-dose intravenous vitamin C (1,500 mg every 6 hours) or placebo. The primary outcome was time from randomization to resolution of vasoplegia. Secondary outcomes included total norepinephrine equivalent dose in the first 2 days, ICU length of stay, ICU mortality, and in-hospital mortality. MEASUREMENTS AND MAIN RESULTS: The authors studied 50 patients (25 patients in each arms). The mean (standard deviation) time to resolution of vasoplegia was 27.0 (16.5) hours in the vitamin C group versus 34.7 (41.1) hours in the placebo group (mean decrease with vitamin C of 7.7 hours, 95% confidence interval -10.5 to 25.9, p = 0.40). The median (interquartile range) norepinephrine equivalent dose in the first 2 days was 64.9 (23.5-236.5) µg/kg versus 47.4 (21.4-265.9) µg/kg in the vitamin C and placebo group (p = 0.75). The median duration of ICU admission was similar (1.4 [0.5-2.5] days and 1.5 [0.5-3.3] days in the vitamin C and placebo group; p = 0.36). Only 1 patient, in the vitamin C arm, died. CONCLUSION: In patients with post-cardiac surgery vasoplegia, high-dose vitamin C infusion was feasible, appeared safe, and, within the limitations of a pilot study, did not achieve statistically faster resolution of vasoplegia.

Sustained High-dose Thiamine Supplementation in High-risk Cardiac Patients Undergoing Cardiopulmonary Bypass: A Pilot Feasibility Study (The APPLY trial).

OBJECTIVE: To test the feasibility and investigate possible cardiovascular effects of a sustained high-dose intravenous thiamine protocol in patients undergoing combined valvular and coronary artery bypass graft surgery. DESIGN: Randomized, placebo-controlled, pilot feasibility trial. SETTING: Cardiac surgery department of a tertiary hospital. PARTICIPANTS: Forty patients undergoing combined valvular and coronary artery bypass surgery. INTERVENTIONS: Intravenous thiamine (600 mg on the day of surgery, and 400 mg/day on postoperative days 1, 2, and 3) or placebo. MEASUREMENTS AND MAIN RESULTS: The primary feasibility endpoints were recruitment rate and protocol compliance. Secondary endpoints included markers of possible biological and physiological effects. The mean recruitment rate was 8 patients per month and protocol compliance was 97.5%. There were no differences in median peak postoperative lactate (2.7 mmol/L [interquartile range [IQR] 1.4-4.6] for thiamine v 2.5 mmol/L [IQR 1.4-3.6] for placebo; p = 0.53), median peak postoperative creatinine (104 µmol/L [IQR 92.5-129] for thiamine v 99 µmol/L [IQR 86.5-109.5] for placebo; p = 0.53), median nadir postoperative cardiac index (1.8 L/min/m2 [IQR 1.5-2.1] for thiamine v 2.2 L/min/m2 [IQR 1.5-2.5] for placebo; p = 0.25), or the number of patients on vasopressor/inotropic agents (thiamine, 12 [63%]; placebo, 12 [60%]; p = 0.80), or in the total inotrope/vasopressor dose 0.14 µg/kg for thiamine v 0.12 µg/kg for placebo; p = 0.88). CONCLUSIONS: A double-blind trial of sustained high-dose intravenous thiamine supplementation in higher-risk cardiac surgery patients was feasible and appeared to be safe. However, such treatment did not demonstrate evidence of biological or physiological effects.

Vitamin C measurement in critical illness: challenges, methodologies and quality improvements.

Background There is renewed interest in high-dose vitamin C interventions in clinical medicine due to its antioxidant properties, safe use and cost-effectiveness. Yet, randomised control trials (RCTs) employing these interventions are failing to include robust analytical methodology and proper sample handling and processing techniques. Consequently, comparisons between studies becomes impossible as there is no metrological traceability and results may be prone to pre-analytical errors. Content Through published vitamin C stability studies, method comparison papers and data from vitamin C external quality assurance programs, an assessment was made on the functionality of current methods for critically ill patient samples. Summary Data was obtained from two external quality assurance programs, two papers assessing sample stability and interlaboratory agreement and a publication on vitamin C method comparisons. A shift from spectrophotometric and enzymatic methodologies to high performance liquid chromatography (HPLC) greatly improved the variability and interlaboratory agreement. Therefore, the current analytical performance of vitamin C HPLC methodologies are acceptable for the requirements of a high-dose vitamin C RCTs. Outlook Recommendations across the total testing process of vitamin C have been provided to improve the quality of the results. The harmonisation of sample handling and processing procedures will further improve the reliability of current analytical methodologies.

Renal Medullary Hypoxia: A New Therapeutic Target for Septic Acute Kidney Injury?

Renal tissue hypoxia has been implicated as a critical mediatory factor in multiple forms of acute kidney injury (AKI), including in sepsis. In sepsis, whole-kidney measures of macrocirculatory flow and oxygen delivery appear to be poor predictors of microcirculatory abnormalities. Studies in experimental hyperdynamic septic AKI have shown that the renal medulla is particularly susceptible to hypoxia early in sepsis, even in the presence of increased global renal blood flow and oxygen delivery. It has been proposed that an early onset of progressive renal medullary hypoxia, leading to oxidative stress and inflammation, can initiate a downward spiral of cellular injury culminating in AKI. Recent experimental studies have shown that clinical therapies for septic AKI, including, fluids, vasopressors, and diuretics, have distinct effects on renal macrocirculation and microcirculation. Herein, we review the clinical and experimental evidence of alterations in global and regional kidney perfusion and oxygenation during septic AKI and associated therapies. We justify the need for investigation of the effects of therapies on renal microcirculatory perfusion and oxygenation. We propose that interventions that do not worsen the underlying renal pathophysiologic and reparative processes in sepsis will reduce the development and/or progression of AKI more effectively.

Vitamin C therapy for patients with sepsis or septic shock: a protocol for a systematic review and a network meta-analysis.

INTRODUCTION: Vasoplegia is common and associated with a poor prognosis in patients with sepsis and septic shock. Vitamin C therapy in combination with vitamin B1 and glucocorticoid, as well as monotherapy in various doses, has been investigated as a treatment for the vasoplegic state in sepsis, through targeting the inflammatory cascade. However, the combination effect and the relative contribution of each drug have not been well evaluated. Furthermore, the best combination between the three agents is currently unknown. We are planning a systematic review (SR) with network meta-analysis (NMA) to compare the different treatments and identify the combination with the most favourable effect on survival. METHODS AND ANALYSIS: We will include all randomised controlled trials comparing any intervention using intravenous vitamin C, vitamin B1 and/or glucocorticoid with another or with placebo in the treatment of sepsis. We are interested in comparing the following active interventions. Very high-dose vitamin C (≥12 g/day), high-dose vitamin C (≥6 g/day), vitamin C (<6 g/day); low-dose glucocorticoid (<400 mg/day of hydrocortisone (or equivalent)), vitamin B1 and combinations of the drugs above. The primary outcome will be all-cause mortality at the longest follow-up within 1 year but 90 days or longer postrandomisation. All relevant studies will be sought through database searches and trial registries. All reference selection and data extraction will be conducted by two independent reviewers. We will conduct a random-effects NMA to synthesise all evidence for each outcome and obtain a comprehensive ranking of all treatments. We will use the surface under the cumulative ranking curve and the mean ranks to rank the various interventions. To differentiate between the effect of combination therapies and the effect of a component, we will employ a component NMA. ETHICS AND DISSEMINATION: This SR does not require ethical approval. We will publish findings from this systematic review in a peer-reviewed scientific journal and present these at scientific conferences. PROSPERO REGISTRATION NUMBER: CRD42018103860.

Pharmacokinetic data support 6-hourly dosing of intravenous vitamin C to critically ill patients with septic shock.

OBJECTIVES: To study vitamin C pharmacokinetics in septic shock. DESIGN: Prospective pharmacokinetic study. SETTING: Two intensive care units. PARTICIPANTS: Twenty-one patients with septic shock enrolled in a randomised trial of high dose vitamin C therapy in septic shock. INTERVENTION: Patients received 1.5 g intravenous vitamin C every 6 hours. Plasma samples were obtained before and at 1, 4 and 6 hours after drug administration, and vitamin C concentrations were measured by high performance liquid chromatography. MAIN OUTCOME MEASURES: Clearance, volume of distribution, and half-life were calculated using noncompartmental analysis. Data are presented as median (interquartile range [IQR]). RESULTS: Of the 11 participants who had plasma collected before any intravenous vitamin C administration, two (18%) were deficient (concentrations < 11 µmol/L) and three (27%) had hypovitaminosis C (concentrations between 11 and 23 µmol/L), with a median concentration 28 µmol/L (IQR, 11-44 µmol/L). Volume of distribution was 23.3 L (IQR, 21.9-27.8 L), clearance 5.2 L/h (IQR, 3.3-5.4 L/h), and half-life 4.3 h (IQR, 2.6-7.5 h). For the participants who had received at least one dose of intravenous vitamin C before sampling, T0 concentration was 258 µmol/L (IQR, 162- 301 µmol/L). Pharmacokinetic parameters for subsequent doses were a median volume of distribution 39.9 L (IQR, 31.4-44.4 L), clearance 3.6 L/h (IQR, 2.6-6.5 L/h), and half-life 6.9 h (IQR, 5.7-8.5 h). CONCLUSION: Intravenous vitamin C (1.5 g every 6 hours) corrects vitamin C deficiency and hypovitaminosis C and provides an appropriate dosing schedule to achieve and maintain normal or elevated vitamin C levels in septic shock.