Thiamine as an adjunctive therapy in cardiac surgery: a randomized, double-blind, placebo-controlled, phase II trial

Whole blood thiamine, intravenous thiamine supplementation and delirium occurrence in the intensive care unit: retrospective cohort analyses

BACKGROUND

Thiamine di-phosphate is an essential cofactor in glucose metabolism, glutamate transformation and acetylcholinesterase activity, pathways associated with delirium occurrence. We hypothesised that a deficiency in whole blood thiamine and intravenous thiamine supplementation could impact delirium occurrence.

AIM

To establish whether a deficiency in whole blood thiamine and/or intravenous thiamine supplementation within 72 h of intensive care admission is associated with delirium occurrence.

METHOD

The first dataset was secondary analysis of a previous study in an intensive care unit in the Netherlands, reported in 2017. The second dataset contained consecutive intensive care admissions 2 years before (period 1: October 2014 to October 2016) and after (period 2: April 2017 to April 2019) routine thiamine supplementation was introduced within 72 h of admission. Delirium was defined as a positive Confusion Assessment Method-Intensive Care Unit score(s) in 24 h.

RESULTS

Analysis of the first dataset (n = 57) using logistic regression showed no relationship between delirium and sepsis or whole blood thiamine, but a significant association with age (p = 0.014). In the second dataset (n = 3074), 15.1% received IV thiamine in period 1 and 62.6% during period 2. Hierarchical regression analysis reported reduction in delirium occurrence in the second period; this did not reach statistical significance, OR = 0.81 (95% CI 0.652-1.002); p = 0.052.

CONCLUSION

No relationship was detected between whole blood thiamine and delirium occurrence on admission, at 24 and 48 h. It remains unclear whether routine intravenous thiamine supplementation during intensive care admission impacts delirium occurrence. Further prospective randomised clinical trials are needed.

Effect of vitamin B1 supplementation on blood creatinine and lactate levels and clinical outcomes in patients in intensive care units: a systematic review and meta-analysis of randomized controlled trials

CONTEXT

The metabolic response to stress can deplete the remaining thiamine stores, leading to thiamine deficiency.

OBJECTIVE

This study is the first meta-analysis of the effectiveness of thiamine supplementation on clinical and biochemical outcomes in adult patients admitted to the intensive care unit (ICU).

DATA SOURCES

Scopus, PubMed, and Cochrane databases were searched to select studies up to 20 November 2022.

STUDY SELECTION

Studies investigating the effect of thiamine supplementation on serum lactate and creatinine levels, the need for renal replacement therapy, length of ICU stay, and mortality rate in ICU patients were selected.

DATA EXTRACTION

After excluding studies based on title and abstract screening, 2 independent investigators reviewed the full texts of the remaining articles. In the next step, a third investigator resolved any discrepancy in the article selection process.

RESULTS

Of 1628 retrieved articles, 8 were selected for final analysis. This study showed that thiamine supplementation reduced the serum creatinine level (P = .03) compared with placebo. In addition, according to subgroup analysis, serum creatinine concentration was significantly lower in patients >60 years old (P < .00001). However, there was no statistically significant difference in the lactate level between the thiamine supplementation and placebo groups (P = .26). Thiamine supplementation did not decrease the risk of all-cause mortality (P = .71) or the need for renal replacement therapy (P = .14). The pooled results of eligible randomized controlled trials also showed that thiamine supplementation did not reduce the length of ICU stay in comparison to the placebo group (P = .39).

CONCLUSION

This meta-analysis provides evidence that thiamine supplementation has a protective effect against blood creatinine increase in ICU patients. However, further high-quality trials are needed to discover the effect of thiamine supplementation on clinical and biochemical outcomes in ICU patients.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO no. CRD42023399710 (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=399710).

Factors associated with increased lactate levels in cardiac surgeries: scoping review

OBJECTIVES

to map the factors associated with increased lactate levels in the postoperative period of cardiac surgery using extracorporeal circulation.

METHODS

this is a scoping review carried out in December 2022, across ten data sources. It was prepared in accordance with the recommendations of the Joanna Briggs Institute and the Preferred Reporting Items for Systematic Reviews and Meta Analyses Extension for Scoping Reviews checklist.

RESULTS

the most recurrent findings in studies regarding the factors responsible for the increase in lactate were: tissue hypoperfusion, cardiopulmonary bypass time and use of vasoactive drugs. In 95% of studies, increased lactate was related to increased patient mortality.

CONCLUSIONS

discussing the causes of possible complications in cardiac surgery patients is important for preparing the team and preventing complications, in addition to ensuring quality recovery.

Management of Vasoplegic Shock in the Cardiovascular Intensive Care Unit after Cardiac Surgery

Vasoplegic shock after cardiac surgery is characterized by hypotension, a high cardiac output, and vasodilation. Much of the understanding of this pathologic state is informed by the understanding of septic shock. Adverse outcomes and mortality are increased with vasoplegic shock. Early recognition and a systematic approach to its management are critical. The need for vasopressors to sustain an adequate blood pressure as well as pharmacologic adjuncts to mitigate the inflammatory inciting process are necessary. The rationale behind vasopressor escalation and consideration of adjuncts are discussed.

Thiamine for Renal Protection in Septic Shock (TRPSS): A Randomized, Placebo-controlled, Clinical Trial

Rationale: Kidney injury is common and associated with worse outcomes in patients with septic shock. Mitochondrial resuscitation with thiamine (vitamin B1) may attenuate septic kidney injury. Objectives: To assess whether thiamine supplementation attenuates kidney injury in septic shock. Methods: The TRPSS (Thiamine for Renal Protection in Septic Shock) trial was a multicenter, randomized, placebo-controlled trial of thiamine versus placebo in septic shock. The primary outcome was change in serum creatinine between enrollment and 72 hours after enrollment. Measurements and Main Results: Eighty-eight patients were enrolled (42 patients received the intervention, and 46 received placebo). There was no significant between-groups difference in creatinine at 72 hours (mean difference, -0.57 mg/dl; 95% confidence interval, -1.18, 0.04; P = 0.07). There was no difference in receipt of kidney replacement therapy (14.3% vs. 21.7%, P = 0.34), acute kidney injury (as defined by stage 3 of the Kidney Disease: Improving Global Outcomes acute kidney injury scale; 54.7% vs. 73.9%, P = 0.07), or mortality (35.7% vs. 54.3%, P = 0.14) between the thiamine and placebo groups. Patients who received thiamine had more ICU-free days (median [interquartile range]: 22.5 [0.0-25.0] vs. 0.0 [0.0-23.0], P < 0.01). In the thiamine-deficient cohort (27.4% of patients), there was no difference in rates of kidney failure (57.1% thiamine vs. 81.5% placebo) or in-hospital mortality (28.6% vs. 68.8%) between groups. Conclusions: In the TRPSS trial, there was no statistically significant difference in the primary outcome of change in creatinine over time. Patients who received thiamine had more ICU-free days, but there was no difference in other secondary outcomes. Clinical trial registered with www.clinicaltrials.gov (NCT03550794).

Evaluation of whole blood thiamine pyrophosphate concentrations in critically ill patients receiving chronic diuretic therapy prior to admission to Turkish intensive care units: A pragmatic, multicenter, prospective study

BACKGROUND/OBJECTIVES

Thiamine plays a pivotal role in energy metabolism. The aim of the study was to determine serial whole blood TPP concentrations in critically ill patients receiving chronic diuretic treatment before ICU admission and to correlate TPP levels with clinically determined serum phosphorus concentrations.

SUBJECTS/METHODS

This observational study was performed in 15 medical ICUs. Serial whole blood TPP concentrations were measured by HPLC at baseline and at days 2, 5 and 10 after ICU admission.

RESULTS

A total of 221 participants were included. Of these, 18% demonstrated low TPP concentrations upon admission to the ICU, while 26% of participants demonstrated low levels at some point during the 10-day study period. Hypophosphatemia was detected in 30% of participants at some point during the 10-day period of observation. TPP levels were significantly and positively correlated with serum phosphorus levels at each time point (P < 0.05 for all).

CONCLUSIONS

Our results show that 18% of these critically ill patients exhibited low whole blood TPP concentrations on ICU admission and 26% had low levels during the initial 10 ICU days, respectively. The modest correlation between TPP and phosphorus concentrations suggests a possible association due to a refeeding effect in ICU patients requiring chronic diuretic therapy.

Thiamine for the Treatment of Cardiac Arrest-Induced Neurological Injury: A Randomized, Blinded, Placebo-Controlled Experimental Study

Background Thiamine supplementation has demonstrated protective effects in a mouse model of cardiac arrest. The aim of this study was to investigate the neuroprotective effects of thiamine in a clinically relevant large animal cardiac arrest model. The hypothesis was that thiamine reduces neurological injury evaluated by neuron-specific enolase levels. Methods and Results Pigs underwent myocardial infarction and subsequently 9 minutes of untreated cardiac arrest. Twenty minutes after successful resuscitation, the pigs were randomized to treatment with either thiamine or placebo. All pigs underwent 40 hours of intensive care and were awakened for assessment of functional neurological outcome up until 9 days after cardiac arrest. Nine pigs were included in both groups, with 8 in each group surviving the entire intensive care phase. Mean area under the curve for neuron-specific enolase was similar between groups, with 81.5 μg/L per hour (SD, 20.4) in the thiamine group and 80.5 μg/L per hour (SD, 18.3) in the placebo group, with an absolute difference of 1.0 (95% CI, -57.8 to 59.8; P=0.97). Likewise, there were no absolute difference in neurological deficit score at the end of the protocol (2 [95% CI, -38 to 42]; P=0.93). There was no absolute mean group difference in lactate during the intensive care period (1.1 mmol/L [95% CI, -0.5 to 2.7]; P=0.16). Conclusions In this randomized, blinded, placebo-controlled trial using a pig cardiac arrest model with myocardial infarction and long intensive care and observation for 9 days, thiamine showed no effect in changes to functional neurological outcome or serum levels of neuron-specific enolase. Thiamine treatment had no effect on lactate levels after successful resuscitation.

The effect of cardiopulmonary bypass on blood thiamine concentration and its association with post-operative lactate concentration

Objective

Cardiothoracic surgery is a large field in Australia, and evidence suggests post-cardiopulmonary bypass (CPB) hyperlactataemia is associated with higher morbidity and mortality. Low thiamine levels are a potentially common yet treatable cause of hyperlactataemia and may occur in the setting of exposure to CPB non-biological material. We hypothesized that cardiopulmonary bypass would result in decreased whole-blood thiamine levels, which may therefore result in increased whole-blood lactate levels in the post-operative period.

Methods

Adult patients undergoing non-emergent CPB were recruited in a single centre, prospective, analytic observational study at Townsville University Hospital, Australia. The primary outcome was a comparison of pre- and post-CPB thiamine diphosphate level, secondarily aiming to assess any relationship between lactate and thiamine levels. Prospective pre- and post-CPB blood samples were taken and analysed at a central reference laboratory.

Results

Data was available for analysis on 78 patients. There was a statistically significant increase in thiamine diphosphate level from pre-CPB: 1.36 nmol/g Hb, standard deviation (SD) 0.31, 95% confidence intervals (CI) 1.29–1.43, to post-CPB: 1.77 nmol/g Hb, SD 0.53, 95% CI 1.43–1.88, p value < 0.001. There was a non-statistically significant (p > 0.05) trend in rising whole-blood lactate levels with increasing time. Analysis of lactate levels at varying time periods found a significant difference between baseline measurements and increased levels at 13–16 h (p < 0.05). There was no significant relationship observed between whole-blood thiamine levels and post-operative lactate levels.

Conclusion

Whole-blood thiamine levels were found to increase immediately post-CPB in those undergoing elective cardiac surgery. There was no correlation between whole-blood thiamine levels and post-operative arterial lactate levels.

Is it time to reconsider the administration of thiamine alone or in combination with vitamin C in critically ill patients? A meta-analysis of clinical trial studies

BACKGROUND

Although the effect of thiamine alone or in combination with vitamin C has been studied in multiple trials (RCT and interventional studies), their results are inconsistent. This meta-analysis aimed to assess impact of thiamine administration alone, thiamine in combination with vitamin C, and co-administration of low-dose hydrocortisone, vitamin C and thiamine (HVT) on clinical outcomes in critically ill patients.

METHODS AND MATERIALS

After electronic searches on PubMed, Scopus, Cochrane Library, and Web of Science databases, initially 3367 papers were found, and 20 interventional studies were included in our analysis. We assessed the risk-difference between treatment and control (standard treatment) groups by pooling available data on ICU length of stay, number of ventilator free days, mortality, and changes in Sequential Organ Failure Assessment (SOFA) scores.

RESULTS

The results of present studies revealed no significant effect of thiamine in combination with vitamin C, and HVT on number of free days of ventilation. Thiamine alone supplementation was associated with high mortality percentage (WMD: 5.17%; 95% CI: 2.67, 7.67). Thiamine in combination with vitamin C had no significant impact on mortality rate. In contrast, HVT could decrease mortality rate (WMD: - 7.23%; 95% CI: - 10.31, - 4.16; I-square: 0.0%). There was no significant effect of thiamine alone, co-administration of thiamine and vitamin C, and HVT on ICU length of stay. The results of the meta-analysis showed that thiamine alone and HVT supplementation had no significant effect on SOFA score. Interestingly, co-supplementation of thiamine and vitamin C had a significant decreasing effect on SOFA score (WMD: - 0.73; 95% CI: - 1.29, - 0.17; I-square: 0.0%).

CONCLUSION

In contrast to HVT, thiamine supplementation alone was associated with increased mortality rate in ICU. However, co-supplementation of thiamine and vitamin C had a significant decreasing effect on SOFA score.

The effects of cardiovascular and orthopaedic surgery on vitamin concentrations: a narrative review of the literature and mechanisms of action

Given the rise in worldwide chronic diseases, supplemented by an aging population, the volume of global major surgeries, encompassing cardiac and orthopedic procedures is anticipated to surge significantly. Surgical trauma can be accompanied by numerous postoperative complications and metabolic changes. The present review summarized the results from studies assessing the effects of orthopedic and cardiovascular surgery on vitamin concentrations, in addition to exploring the possible mechanisms associated with changes in concentrations. Studies have revealed a potentially severe depletion in plasma/serum concentrations of numerous vitamins following these surgeries acutely. Vitamins C, D and B1 appear particularly vulnerable to significant depletions, with vitamin C and D depletions consistently transpiring into inadequate and deficient concentrations, respectively. The possible multifactorial mechanisms impacting postoperative vitamin concentrations include changes in hemodilution and vitamin utilization, redistribution, circulatory transport and absorption. For a majority of vitamins, there has been a lack of investigation into the effects of both, cardiac and orthopedic surgery. Additionally, studies were predominantly restricted to short-term postoperative investigations, primarily performed within the first postoperative week of surgery. Overall, results indicated that further examination is necessary to determine the severity and clinical significance of the possible depletions in vitamin concentrations that ensue cardiovascular and orthopedic surgery.

Delirium in Critical Illness Patients and the Potential Role of Thiamine Therapy in Prevention and Treatment: Findings from a Scoping Review with Implications for Evidence-Based Practice

INTRODUCTION

Thiamine is a water-soluble vitamin and is necessary for energy metabolism. Critically ill patients are at particular risk of developing thiamine deficiency and related complications. One of the complications that can occur is delirium. Delirium is a disorder that affects the body's response to treatment, length of stay in the ward, mortality, long-term cognitive impairment, and significantly increases treatment costs. In addition, studies show that delirium medication is more effective in preventing than in treating delirium. Given its low cost, availability, and minimal risk of side effects, thiamine supplementation could prove to be a relevant strategy in the prevention and treatment of delirium.

METHODS

PubMed, Cochrane Library, Ovid, and ClinicalTrials.gov databases were searched using relevant keywords that focus on the use of thiamine to prevent or treat delirium in critically ill patients.

RESULTS

Seven articles were included in the analysis.

CONCLUSION

The small number of studies and considerable heterogeneity prevent conclusions supporting the use of thiamine as an adjuvant in the prevention and treatment of delirium among critically ill patients. There is a need for high-quality, large-scale randomized clinical trials to confirm the beneficial effects of thiamine in the prevention and treatment of delirium.

Thiamine levels in Indonesian children with congenital heart diseases undergoing surgery using cardiopulmonary bypass machine

BACKGROUND

This study evaluated thiamine levels in Indonesian children with congenital heart diseases before and after cardiopulmonary bypass and their relationship with clinical and surgical outcomes.

METHOD

A prospective, single center cross-sectional study was conducted to evaluate thiamine levels in 25 children undergoing congenital heart diseases surgery with cardiopulmonary bypass procedure. Thiamine levels were quantified using a high-performance liquid chromatography method.

RESULT

Preoperative thiamine deficiency was observed in one subject. Thiamine levels did not differ statistically between nutritional status and clinical outcomes categories. There were no significant changes in thiamine levels before and after cardiopulmonary bypass (median pre versus post (P_25-75): 50 ng/mL (59.00-116.00) and 83.00 ng/mL (70.00-101.00), p = 0.84), although a significant reduction in thiamine levels were observed with longer cardiopulmonary bypass duration (p = 0.017, R = -0.472).

CONCLUSION

Thiamine levels were not significantly impacted by cardiac surgery except in patients undergoing extremely long cardiopulmonary bypass duration. However, clinical outcome was not affected by thiamine levels.

Effect of thiamine supplementation in critically ill patients: A systematic review and meta-analysis

INTRODUCTION

Several studies have previously shown the benefit of thiamine supplementation in critically ill patients. In order to fully appraise the available data, we performed a meta-analysis of 18 published studies.

METHODS

A thorough systematic search was conducted. The studies enrolling critically ill patients receiving thiamine supplementation was compared with the standard of care (SOC) group. Data was analyzed using RevMan 5.4. Clinical outcomes were pooled using Odds Ratio (OR) and mean differences.

RESULT

Eighteen studies (8 RCTs and 10 cohort studies) met the criteria for quantitative synthesis. In the analysis of RCTs, thiamine supplementation showed 42% lower odds of developing ICU delirium (OR 0.58, 95% CI, 0.34-0.98). A reduction in mortaliy was observed on performing fixed effect model analysis however, a level of statistical significance could not be reached on performing randon effect model analysis (OR, 0.78; 95% CI, 0.59 to 1.04). Further sub-group analysis of 13 studies in patients with sepsis, there was no difference in mortality between the two groups (OR, 0.83; 95% CI, 0.63 to 1.09).

CONCLUSION

Thiamine supplementation in critically ill patients showed a reduction in the incidence of ICU delirium among RCTs. However, there was no significant benefit in terms of overall mortality, and mortality in patients with sepsis. Further, large scale randomized prospective studies are warranted to investigate the role of thiamine supplementation in critically ill patients.

Effects of thiamine on vasopressor requirements in patients with septic shock: a prospective randomized controlled trial

Background

Thiamine, an essential vitamin for aerobic metabolism and glutathione cycling, may decrease the effects of critical illnesses. The objective of this study was to determine whether intravenous thiamine administration can reduce vasopressor requirements in patients with septic shock.

Methods

This study was a prospective randomized double-blind placebo-controlled trial. We included adult patients with septic shock who required a vasopressor within 1–24 h after admission between March 2018 and January 2019 at a tertiary hospital in Thailand. Patients were divided into two groups: those who received 200 mg thiamine or those receiving a placebo every 12 h for 7 days or until hospital discharge. The primary outcome was the number of vasopressor-free days over 7 days. The pre-defined sample size was 31 patients per group, and the study was terminated early due to difficult recruitment.

Results

Sixty-two patients were screened and 50 patients were finally enrolled in the study, 25 in each group. There was no difference in the primary outcome of vasopressor-free days within the 7-day period between the thiamine and placebo groups (mean: 4.9 days (1.9) vs. 4.0 days (2.7), p = 0.197, mean difference − 0.9, 95% CI (− 2.9 to 0.5)). However, the reductions in lactate (p = 0.024) and in the vasopressor dependency index (p = 0.02) at 24 h were greater among subjects who received thiamine repletion vs. the placebo. No statistically significant difference was observed in SOFA scores within 7 days, vasopressor dependency index within 4 days and 7 days, or 28-day mortality.

Conclusions

Thiamine was not associated to a significant reduction in vasopressor-free days over 7-days in comparison to placebo in patients with septic shock. Administration of thiamine could be associated with a reduction in vasopressor dependency index and lactate level within 24 h. The study is limited by early stopping and low sample size.

Trial registration

TCTR, TCTR20180310001. Registered 8 March 2018, http://www.clinicaltrials.in.th/index.php?tp=regtrials&menu=trialsearch&smenu=fulltext&task=search&task2=view1&id=3330.

Supplementary Information

Supplementary information accompanies this paper at 10.1186/s12871-020-01195-4.

Thiamine treatment preserves cardiac function against ischemia injury via maintaining mitochondrial size and ATP levels

Thiamine (vitamin B1) is necessary for energy production, especially in the heart. Recent studies have demonstrated that thiamine supplementation for cardiac diseases is beneficial. However, the detailed mechanisms underlying thiamine-preserved cardiac function have not been elucidated. To this end, we conducted a functional analysis, metabolome analysis, and electron microscopic analysis to unveil the mechanisms of preserved cardiac function through supplementation with thiamine for ischemic cardiac disease. Male Sprague-Dawley rats (around 10 wk old) were used. Following pretreatment with or without thiamine pyrophosphate (TPP; 300 µM), hearts were exposed to ischemia (40 min of global ischemia followed by 60 min of reperfusion). We measured the left ventricle developed pressure (LVDP) throughout the protocol. The LVDP during reperfusion in the TPP-treated heart was significantly higher than that in the untreated heart. Metabolome analysis was performed using capillary electrophoresis-time-of-flight mass spectrometry, and it revealed that the TPP-treated heart retained higher adenosine triphosphate (ATP) levels compared with the untreated heart after ischemia. The metabolic pathway showed that there was a significant increase in fumaric acid and malic acid from the tricarboxylic acid cycle following ischemia. Electron microscope analysis revealed that the mitochondria size in the TPP-treated heart was larger than that in the untreated heart. Mitochondrial fission in the TPP-treated heart was also inhibited, which was confirmed by a decrease in the phosphorylation level of DRP1 (fission related protein). TPP treatment for cardiac ischemia preserved ATP levels probably as a result of maintaining larger mitochondria by inhibiting fission, thereby allowing the TPP-treated heart to preserve contractility performance during reperfusion.NEW & NOTEWORTHY We found that treatment with thiamine can have a protective effect on myocardial ischemia. Thiamine likely mediates mitochondrial fission through the inhibition of DRP1 phosphorylation and the preservation of larger-sized mitochondria and ATP concentration, leading to higher cardiac contractility performance during the subsequent reperfusion state.

Efficacy of Thiamine in the Treatment of Postcardiac Arrest Patients: A Randomized Controlled Study

Background

Thiamine administration has been shown to improve survival in a postcardiac arrest animal study. We aimed to evaluate the efficacy of thiamine in comatose out-of-hospital cardiac arrest (OHCA) patients following return of spontaneous circulation.

Methods

A randomized, double-blinded, placebo-controlled study was conducted. Thirty-seven OHCA patients were randomly assigned to receive either thiamine 100 mg every 8 hours or a placebo. The primary outcome was 28-day all-cause mortality.

Results

Over the course of 2 years, 37 patients were randomized to either receive thiamine (n = 20) or a placebo (n = 17). The primary outcome was not different between the groups: 10/20 (50%) in the thiamine group vs. 8/17 (47.1%) in the placebo group (P=0.93 by the log-rank test). There were no significant differences in secondary outcomes between the groups (good neurological outcome, lactate level, and S100B level).

Conclusions

In this study, there were no significant differences in survival outcome. Further studies with a larger population are necessary to confirm these results.

Melatonin for the treatment of sepsis: the scientific rationale

Sepsis affects 30 million people worldwide, leading to 6 million deaths every year (WHO), and despite decades of research, novel initiatives are drastically needed. According to the current literature, oxidative imbalance and mitochondrial dysfunction are common features of septic patients that can cause multiorgan failure and death. Melatonin, alongside its traditionally accepted role as the master hormonal regulator of the circadian rhythm, is a promising adjunctive drug for sepsis through its anti-inflammatory, antiapoptotic and powerful antioxidant properties. Several animal models of sepsis have demonstrated that melatonin can prevent multiorgan dysfunction and improve survival through restoring mitochondrial electron transport chain (ETC) function, inhibiting nitric oxide synthesis and reducing cytokine production. The purpose of this article is to review the current evidence for the role of melatonin in sepsis, review its pharmacokinetic profile and virtual absence of side effects. While clinical data is limited, we propose the adjunctive use of melatonin is patients with severe sepsis and septic shock.

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.

Thiamine deficiency affects glucose transport and β-oxidation in rats

Thiamine is recognized as a cofactor for many enzymes involved in intermediary metabolism responsible for energy production. Animal model of thiamine deficiency (TD) included direct evaluation of glucose uptake by estimation of ³H‐deoxyglucose transport across red blood cells membranes and β‐oxidation of fatty acids in isolated leucocytes. Feeding of animals with the thiamine‐deficient diet (0.018 mg/kg diet) for 30 days resulted in disturbances in energy production. The thiamine intake was limited not only by vitamin B₁ deficiency in the diet, but also by time‐dependent drop of feed consumption by rats fed this diet. At the end of experiment, diet consumption in this group of rats was 52% lower than in the control group. This was accompanied by low glucose uptake by erythrocytes of rats suffering vitamin B₁ deficiency for longer time. At the end of experimental period, glucose uptake was over 2 times lower in TD erythrocytes than in control RBC. Such drop of energy production was not compensated by delivery of energy from fatty acid degradation. In leucocytes from TD rats, the β‐oxidation was also suppressed. Observed significant decrease of serum insulin from 2.25 ± 0.25 ng/ml (day 0) to 1.94 ± 0.17 ng/ml (day 30) might have significant impact on observed energy production disorders. The results from this study indicate that the thiamine deficiency significantly reduces feed intake and causes modest abnormalities in glucose and fatty acid utilization.

Ascorbic acid, corticosteroids, and thiamine in sepsis: a review of the biologic rationale and the present state of clinical evaluation

The combination of thiamine, ascorbic acid, and hydrocortisone has recently emerged as a potential adjunctive therapy to antibiotics, infectious source control, and supportive care for patients with sepsis and septic shock. In the present manuscript, we provide a comprehensive review of the pathophysiologic basis and supporting research for each element of the thiamine, ascorbic acid, and hydrocortisone drug combination in sepsis. In addition, we describe potential areas of synergy between these therapies and discuss the strengths/weaknesses of the two studies to date which have evaluated the drug combination in patients with severe infection. Finally, we describe the current state of current clinical practice as it relates to the thiamine, ascorbic acid, and hydrocortisone combination and present an overview of the randomized, placebo-controlled, multi-center Ascorbic acid, Corticosteroids, and Thiamine in Sepsis (ACTS) trial and other planned/ongoing randomized clinical trials.

Thiamine Deficiency: An Important Consideration in Critically Ill Patients

Thiamine is an essential cofactor for 4 enzymes involved in the production of energy (ATP) and the synthesis of essential cellular molecules. The total body stores of thiamine are relatively small, and thiamine deficiency can develop in patients secondary to inadequate nutrition, alcohol use disorders, increased urinary excretion and acute metabolic stress. Patients with sepsis are frequently thiamine deficient, and patients undergoing surgical procedures can develop thiamine deficiency. This deficiency can cause congestive heart failure, peripheral neuropathy, Wernicke's encephalopathy, Korsakoff's syndrome and gastrointestinal beriberi. In addition, thiamine deficiency can contribute to the development of intensive care unit complications, such as heart failure, delirium, critical care neuropathy, gastrointestinal dysfunction and unexplained lactic acidosis. Consequently, clinicians need to consider thiamine deficiency in patients admitted to intensive care units and the development of thiamine deficiency during the management of critically ill patients. Intravenous thiamine can correct lactic acidosis, improve cardiac function and treat delirium.

Current Evidence about Nutrition Support in Cardiac Surgery Patients-What Do We Know?

Nutrition support is increasingly recognized as a clinically relevant aspect of the intensive care treatment of cardiac surgery patients. However, evidence from adequate large-scale studies evaluating its clinical significance for patients&rsquo; mid- to long-term outcome remains sparse. Considering nutrition support as a key component in the perioperative treatment of these critically ill patients led us to review and discuss our understanding of the metabolic response to the inflammatory burst induced by cardiac surgery. In addition, we discuss how to identify patients who may benefit from nutrition therapy, when to start nutritional interventions, present evidence about the use of enteral and parenteral nutrition and the potential role of pharmaconutrition in cardiac surgery patients. Although the clinical setting of cardiac surgery provides advantages due to its scheduled insult and predictable inflammatory response, researchers and clinicians face lack of evidence and several limitations in the clinical routine, which are critically considered and discussed in this paper.

Lactate Elevation During and After Major Cardiac Surgery in Adults: A Review of Etiology, Prognostic Value, and Management

Elevated lactate is a common occurrence after cardiac surgery. This review summarizes the literature on the complex etiology of lactate elevation during and after cardiac surgery, including considerations of oxygen delivery, oxygen utilization, increased metabolism, lactate clearance, medications and fluids, and postoperative complications. Second, the association between lactate and a variety of outcomes are described, and the prognostic role of lactate is critically assessed. Despite the fact that elevated lactate is strongly associated with many important outcomes, including postoperative complications, length of stay, and mortality, little is known about the optimal management of postoperative patients with lactate elevations. This review ends with an assessment of the limited literature on this subject.