Diagnosis and treatment of Wernicke's encephalopathy: A systematic literature review

BACKGROUND

Wernicke's encephalopathy (WE) is a serious neurological disorder that is underdiagnosed. Despite limited clinical guidelines, the standard use of intravenous (IV) thiamine is underutilized and remains an area of research deserving much attention.

OBJECTIVES

We conducted a systematic review using Medline, Embase, and CENTRAL databases to identify and summarize the literature on IV thiamine treatment in WE. Human studies with WE patients who received ≥100 mg of thiamine IV met inclusion criteria. Randomized controlled trials, cross-sectional studies, and case reports were included.

RESULTS

A total of 27 studies were included: 20 case reports, five retrospective studies, one prospective study and one randomized control trial. Of the case reports, 11 (55%) cases were female, and the average age of all cases was 45 years (SD = 15). The other seven studies included 688 patients; the average age was 52 years (SD = 9), and 266 (38.7%) were female. Among the case reports, neurological and clinical findings were used to diagnose WE in 16 (80%) cases. MRI was utilized to diagnose 15 (75%) cases. 500 mg IV thiamine TID was reported in 12 case reports (60%). 18 (90%) of case reports had partial or complete resolution of symptoms following IV thiamine.

CONCLUSION

IV thiamine can alleviate neurological symptoms, cognitive dysfunction, and brain imaging lesions associated with WE. We found key limitations in the evidence for IV thiamine and diagnostic standards for WE. Future targeted research should establish clear diagnostic and treatment guidelines for WE to prevent this serious condition from being underdiagnosed or undertreated.

Thiamine deficiency-related neuropathy: A reversible entity from an endemic area

BACKGROUND AND PURPOSE

Despite thiamine deficiency being a lesser-known entity in modern times, beriberi in various forms, including thiamine deficiency-related neuropathy, remains endemic in Kashmir due to the consumption of polished rice as a staple food. This observational study investigates cases of peripheral neuropathy of unknown etiology and their potential responsiveness to thiamine administration.

METHODS

This prospective study enrolled adult patients presenting to the emergency department with weakness consistent with thiamine deficiency-related neuropathy and conducted a therapeutic challenge with thiamine on 41 patients. Response to thiamine therapy was monitored based on subjective and objective improvements in weakness and power. Patients were divided into thiamine responders (n = 25) and nonresponders (n = 16) based on their response to thiamine therapy and nerve conduction studies.

RESULTS

Most of the baseline characteristics were similar between responders and nonresponders, except the responders exhibited lower thiamine levels and higher partial pressure of oxygen and lactate levels compared to nonresponders. All patients had a history of consuming polished rice and traditional salt tea. Although weakness in the lower limbs was present in both groups, nonresponders were more likely to exhibit weakness in all four limbs. Clinical improvement was observed within 24 h, but proximal muscle weakness persisted for an extended period of time.

CONCLUSIONS

Thiamine deficiency-related neuropathy presents with predominant lower limb weakness, exacerbated by vomiting, poor food intake, psychiatric illness, and pregnancy. Thiamine challenge should be followed by observation of clinical and biochemical response.

Wernicke's Encephalopathy in Acute and Chronic Kidney Disease: A Systematic Review

Thiamine (vitamin B1) deficiency is relatively common in patients with kidney disease. Wernicke's encephalopathy (WE) is caused by vitamin B1 deficiency. Our aim was to systematically review the signs and symptoms of WE in patients with kidney disease. We conducted a systematic literature review on WE in kidney disease and recorded clinical and radiographic characteristics, treatment and outcome. In total 323 manuscripts were reviewed, which yielded 46 cases diagnosed with acute and chronic kidney disease and WE published in 37 reports. Prodromal characteristics of WE were loss of appetite, vomiting, weight loss, abdominal pain, and diarrhea. Parenteral thiamine 500 mg 3 times per day often led to full recovery, while Korsakoff's syndrome was found in those receiving low doses. To prevent WE in kidney failure, we suggest administering high doses of parenteral thiamine in patients with kidney disease who present with severe malnutrition and (prodromal) signs of thiamine deficiency.

Thiamine administration in septic shock: a post hoc analysis of two randomized trials

BACKGROUND

This is a post hoc analysis of combined cohorts from two previous Phase II clinical trials to assess the effect of thiamine administration on kidney protection and mortality in patients with septic shock.

METHODS

Patient-level data from the Thiamine in Septic Shock Trial (NCT01070810) and the Thiamine for Renal Protection in Septic Shock Trial (NCT03550794) were combined in this analysis. The primary outcome for the current study was survival without the receipt of renal replacement therapy (RRT). Analyses were performed on the overall cohort and the thiamine-deficient cohort (thiamine < 8 nmol/L).

RESULTS

Totally, 158 patients were included. Overall, thiamine administration was associated with higher odds of being alive and RRT-free (adjusted odds ratio [aOR]: 2.05 [95% confidence interval (CI) 1.08-3.90]) and not needing RRT (aOR: 2.59 [95% CI 1.01-6.62]). In the thiamine-deficient group, thiamine administration was associated with higher odds of being alive and RRT-free (aOR: 8.17 [95% CI 1.79-37.22]) and surviving to hospital discharge (aOR: 6.84 [95% CI 1.54-30.36]). There was a significant effect modification by baseline thiamine deficiency for alive and RRT-free (interaction, p = 0.016) and surviving to hospital discharge (p = 0.019).

CONCLUSION

In the combined analysis of two previous randomized trials, thiamine administration was associated with higher odds of being alive and RRT-free at hospital discharge in patients with septic shock. This signal was stronger in patients with thiamine deficiency.

Atypical Wernicke's encephalopathy without mental status changes following bariatric surgery in an adolescent patient

Morbid obesity is a systemic disease which can result in chronic complications, including hypertension, diabetes mellitus, depression, osteoarthritis and low self-esteem in the adolescent population.Bariatric surgery can be indicated to treat more severe forms of obesity, but these procedures are not without long-term risks. Therefore, adequate preoperative and postoperative care, which includes preoperative psychosocial evaluation for compliance, ongoing nutrition counselling and vitamin and micronutrient supplementation, is required for all patients, especially adolescent patients, who generally may not comply with medical therapies and/or be able to developmentally fully appreciate or comprehend the health consequences of their behaviours, prior to as well as after bariatric surgery to prevent complications.Thiamine pyrophosphate, an active form of thiamine (also known as vitamin B1, a water-soluble vitamin), which functions as a coenzyme in glucose and energy metabolism, is one such vitamin that requires supplementation postoperatively. It is mandatory for glucose to be administered concomitantly with thiamine, as glucose alone can precipitate Wernicke's encephalopathy (WE) in thiamine-deficient individuals. WE is a medical emergency, with a mortality rate of up to 20%. WE is best understood as a classic triad of mental confusion, gait ataxia and eye movement abnormalities, and atypical WE or Wernicke's syndrome (WS) is seen when the classic triad is not present. Cases that meet some, but do not necessarily meet all three criteria, are referred to as atypical WE or WS which can lead to delayed diagnosis. Atypical WE has an incidence of 19% which can lead to misdiagnosis of a preventable medical emergency with fatal complications.The following case reviews the consequences of post-bariatric thiamine supplementation therapy non-adherence and resulting in a deficiency in an adolescent patient.

Descriptive spectrum of thiamine deficiency in pregnancy: A potentially preventable condition

OBJECTIVE

Pregnancy, a nutritionally demanding situation in terms of macro- and micronutrient supply owing to heightened maternal, placental, and fetal needs, significantly affects thiamine reserves. Thiamine deficiency during pregnancy and the postpartum period, presenting with varied manifestations and outcomes, is a relatively common condition in our population. The study aimed to understand the various manifestations and outcomes of acute thiamine deficiency in pregnant and postpartum women, emphasizing the significance of early recognition and thiamine therapy to prevent serious complications during pregnancy and after childbirth.

METHODS

This prospective study conducted in a tertiary care center in North India enrolled consecutive pregnant and postpartum women presenting with clinical features consistent with thiamine deficiency disorders, such as thiamine deficiency-related neuropathy, high-output heart failure, heart failure with reduced ejection fraction, Wernicke's encephalopathy, gastric beriberi, and thiamine-responsive acute pulmonary hypertension. In addition to capturing medical history including drug intake, dietary consumption, and comorbidities, women underwent brief relevant clinical examinations and laboratory assessments, including whole-blood thiamine levels. Response to intravenous thiamine supplementation was also monitored.

RESULTS

Data of 31 women (12 pregnant, 19 postpartum) with a diagnosis of acute thiamine deficiency and a mean age of 28.88 ± 2.69 years were analyzed. The mean thiamine level was 1.28 ± 0.44 μg/dL with mean blood lactate of 3.46 ± 3.33. The most common presentation was gastric beriberi (n = 10), followed by paraparesis (n = 6), high-output heart failure (n = 6), acute pulmonary hypertension, heart failure with reduced ejection fraction (n = 3 each), and an acute confusional state (n = 2). All patients responded to thiamine challenge.

CONCLUSION

In the context of borderline thiamine status, particularly in our population with endemic thiamine deficiency and heightened demand for thiamine during pregnancy and the peripartum period, the deficiency can have varied and serious manifestations of dry and wet beriberi. Early recognition of the clinical features and thiamine therapy can be life-saving. There is a need for validated clinical criteria owing to the non-availability of thiamine testing in resource-limited settings.

Wernicke encephalopathy: limitations in a laboratory and radiological diagnosis

Wernicke encephalopathy is an emergent neurological disorder caused by vitamin B1 (thiamine) deficiency. Here, we present a case of Wernicke encephalopathy in a male patient in his 70s with normal serum thiamine levels and MRI findings on admission. He had a history of heavy alcohol consumption and a gradual decrease in food intake. On arrival at the hospital, his consciousness was impaired which persisted even after glucose replacement. Moreover, horizontal nystagmus and cerebellar ataxia were observed. Head CT scan and MRI revealed no abnormal findings. Further, his serum thiamine level was within the normal range. The patient was clinically diagnosed with Wernicke encephalopathy, and high-dose thiamine therapy was started. Then, his symptoms improved immediately. Thus, in case of clinical suspicion, treatment for Wernicke encephalopathy must be initiated promptly even in patients with normal serum thiamine levels.

Treatment variability and its relationships to outcomes among patients with Wernicke's encephalopathy: A multicenter retrospective study

BACKGROUND

Despite guidelines and recommendations, Wernicke's encephalopathy (WE) treatment lacks evidence, leading to clinical practice variability.

AIMS

Given the overall lack of information on thiamine use for WE treatment, we analyzed data from a large, well-characterized multicenter sample of patients with WE, examining thiamine dosages; factors associated with the use of different doses, frequencies, and routes; and the influence of differences in thiamine treatment on the outcome.

METHODS

This retrospective study was conducted with data from 443 patients from 21 centers obtained from a nationwide registry of the Spanish Society of Internal Medicine (from 2000 to 2012). Discharge codes and Caine criteria were applied for WE diagnosis, and treatment-related (thiamine dosage, frequency, and route of administration) demographic, clinical, and outcome variables were analyzed.

RESULTS

We found marked variability in WE treatment and a low rate of high-dose intravenous thiamine administration. Seventy-eight patients out of 373 (20.9%) received > 300mg/day of thiamine as initial dose. Patients fulfilling the Caine criteria or presenting with the classic WE triad more frequently received parenteral treatment. Delayed diagnosis (after 24h hospitalization), the fulfillment of more than two Caine criteria at diagnosis, mental status alterations, and folic acid deficiency were associated significantly with the lack of complete recovery. Malnutrition, reduced consciousness, folic acid deficiency, and the lack of timely thiamine treatment were risk factors for mortality.

CONCLUSIONS

Our results clearly show extreme variability in thiamine dosages and routes used in the management of WE. Measures should be implemented to ensure adherence to current guidelines and to correct potential nutritional deficits in patients with alcohol use disorders or other risk factors for WE.

Thiamine deficiency disorders in women and children

Thiamine (vitamin B1) is available in common foods such as the outer husk of rice and is necessary for normal cardiovascular, neurological and metabolic processes. Thiamine deficiency is common in many parts of Asia and Africa, affecting up to a third or more of children and women of child-bearing age. The diagnosis is based on clinical suspicion, especially when noting heart failure in infants, encephalopathy in patients of any age, and peripheral neuropathy in older children and adults. Blood tests for whole-blood thiamine diphosphate (the quantity of biologically active thiamine present) and erythrocyte transketolase activity (the functional impact of thiamine) are not always readily available in areas where thiamine deficiency is common. Treatment is safe and effective, although dosing guidelines vary widely; 50 mg daily for 5 days is probably effective for treating acute thiamine deficiency disorders, and ongoing adequate thiamine intake is also needed. Prevention efforts depend on local and regional circumstances, including dietary diversification, food fortification, and/or supplementation of children and women at risk.Abbreviations: HIC: high-income countries; LMIC: low- and middle-income countries; MRI: magnetic resonance imaging; TDD: thiamine deficiency disorders.

Thiamine-Responsive Megaloblastic Anaemia With Hypothyroidism, A Puzzling Association

Background

Thiamine-responsive megaloblastic anaemia (TRMA) is characterized by the classic trio of diabetes mellitus, sensorineural hearing loss, and megaloblastic anaemia, typically emerging subtly between infancy and adolescence. Administration of high-dose thiamine often yields improvements in anaemia and occasionally in diabetes. Uncommon manifestations include optic atrophy, congenital heart defects, short stature, and stroke. In this specific case, a 5-year-old diagnosed with insulin-dependent diabetes mellitus (IDDM) since the age of one presented with symptoms such as polyuria, fever, and vomiting, revealing an HbA1c of 10.64. Further examinations disclosed compromised hearing and vision. A negative antibody workup and a thyroid profile indicating hypothyroidism prompted additional investigations, including Brainstem Evoked Response Audiometry (BERA) and retinal examination, confirming bilateral sensorineural hearing loss and maculopathy, respectively. A comprehensive blood count unveiled megaloblastic anaemia. Genetic profiling confirmed a homozygous mutation in the SLC19A2 gene, thus diagnosing TRMA. An early diagnosis, coupled with genetic confirmation, enables timely intervention, with patients responding positively to high-dose thiamine. Genetic counselling plays a pivotal role in enlightening families about the disease and its inheritance patterns, fostering awareness and understanding.

Thiamine responsive high output heart failure of adults: an under-recognized entity

Thiamine deficiency, commonly presenting as dry and wet beriberi, a lesser-known entity in the present era, is increasingly being reported from Kashmir, a north Indian state. The present study aims to present the clinical profile of patients presenting with high-output heart failure (HOHF). Subjects with a primary diagnosis of denovo heart failure and features suggestive of HOHF were recruited; those who responded to intravenous administration of thiamine alone (responders) were adults with no co-morbidities and those who required other medications particularly diuretics (non-responders) were elderly with co-morbidities and underlying heart disease. Responders showed considerably lower mean thiamine pyrophosphate (TPP) levels and higher mean lactate and venous oxygen saturation than non-responders. More importantly, the mean drop in lactate and SVO2 following thiamine therapy was more in responders. In a setting of high risk for thiamine deficiency, features suggestive of HOHF along with elevated lactate and higher venous oxygen saturation, a response to thiamine challenge may serve as surrogate marker of thiamine deficiency.

Diagnostic Dilemma of Lactic Acidosis in an Infant After Liver Transplant: A Case Report

Thiamine is the cofactor of many enzymes involved in energy metabolism. Patients under total parenteral nutrition are at risk for thiamine deficiency if there is renal thiamine loss or increased thiamine requirements to mitigate systemic diseases. Thiamine deficiency symptoms include seizures, neuropathy, ataxia, peripheral vasodilation, myocardial insufficiency, sudden collapse, and death. In this report, we present an infant liver transplant recipient with progressive lactic acidosis that responded well to thiamine replacement to mitigate a lack of thiamine in total parenteral nutrition.

Wernicke encephalopathy and beriberi disease presenting as STEMI-equivalent

Thiamine deficiency is commonly associated with malnutrition, alcoholism and bariatric surgery. Thiamine deficiency can manifest in different ways, especially in developing countries: as peripheric neuropathy, as Wernicke encephalopathy or as beriberi disease. The authors present the case of a 72-year-old male, with a hiatal hernia that led to thiamine deficiency due to malnutrition. The initial clinical manifestation was an ST-elevation myocardial infarct equivalent, an ECG with a shark-fin pattern that evolved to a Wellens type B pattern. The patient evolved with severe altered mental status. A Wernicke encephalopathy diagnosis was confirmed by MRI; the patient was medicated with high-dose thiamine, with quick recovery, both neurologic and cardiac. The clinical history and response to treatment confirm the diagnosis of Wernicke encephalopathy and beriberi disease.

Early detection of thiamine deficiency by non-thyroidal illness syndrome in a hemodialysis patient

An 88-year-old male patient on maintenance hemodialysis (HD) therapy experienced gradual losses in appetite and liveliness during the course of 1 month. Physical examinations revealed no abnormalities. However, blood testing indicated non-thyroidal illness syndrome (NTIS) typically observed in patients with severe illness, with serum levels of thyroid stimulating hormone, free triiodothyronine, and free thyroxine of 0.17 μIU/mL, < 1.0 pg/mL, and 0.23 ng/dL, respectively. Brain magnetic resonance imaging to exclude the possibility of central hypothyroidism unexpectedly displayed slight abnormalities inside of the thalami that were characteristic of Wernicke's encephalopathy. Additional examination disclosed low serum thiamine of 20 ng/mL. Thiamine injections of 100 mg at every HD treatment rapidly restored his appetite, liveliness, and NTIS findings. HD patients are at a particularly high risk of thiamine deficiency (TD) and associated severe symptoms due to losses of thiamine during HD sessions. However, its non-specific initial symptoms, including decreases in appetite and liveliness, as well as undetectability in routine blood tests complicate early detection, resulting in underdiagnosis and more severe outcomes. In the present case, TD manifested only as non-specific symptoms and was ultimately revealed by the presence of NTIS, which was resolved with thiamine supplementation. Thus, NTIS might assist in the early detection of TD as an initial sign in HD patients.

Protocatechuic Acid Prevents Some of the Memory-Related Behavioural and Neurotransmitter Changes in a Pyrithiamine-Induced Thiamine Deficiency Model of Wernicke-Korsakoff Syndrome in Rats

The purpose of this research was to investigate the effects of protocatechuic acid (PCA) at doses of 50 and 100 mg/kg on the development of unfavourable changes in cognitive processes in a pyrithiamine-induced thiamine deficiency (PTD) model of the Wernicke-Korsakoff syndrome (WKS) in rats. The effects of PCA were assessed at the behavioural and biochemical levels. Behavioural analysis was conducted using the Foot Fault test (FF), Bar test, Open Field test, Novel Object Recognition test (NOR), Hole-Board test and Morris Water Maze test (MWM). Biochemical analysis consisting of determination of concentration and turnover of neurotransmitters in selected structures of the rat CNS was carried out using high-performance liquid chromatography. PTD caused catalepsy (Bar test) and significantly impaired motor functions, leading to increased ladder crossing time and multiplied errors due to foot misplacement (FF). Rats with experimentally induced WKS showed impaired consolidation and recall of spatial reference memory in the MWM test, while episodic memory related to object recognition in the NOR was unimpaired. Compared to the control group, rats with WKS showed reduced serotonin levels in the prefrontal cortex and changes in dopamine and/or norepinephrine metabolites in the prefrontal cortex, medulla oblongata and spinal cord. PTD was also found to affect alanine, serine, glutamate, and threonine levels in certain areas of the rat brain. PCA alleviated PTD-induced cataleptic symptoms in rats, also improving their performance in the Foot Fault test. In the MWM, PCA at 50 and 100 mg/kg b.w. improved memory consolidation and the ability to retrieve acquired information in rats, thereby preventing unfavourable changes caused by PTD. PCA at both tested doses was also shown to have a beneficial effect on normalising PTD-disrupted alanine and glutamate concentrations in the medulla oblongata. These findings demonstrate that certain cognitive deficits in spatial memory and abnormalities in neurotransmitter levels persist in rats that have experienced an acute episode of PTD, despite restoration of thiamine supply and long-term recovery. PCA supplementation largely had a preventive effect on the development of these deficits, to some extent also normalising neurotransmitter concentrations in the brain.

[Thiamin: Simply a vitamin?]

Vitamin B1 also known as thiamin is an essential vitamin assuring body functioning and comes exclusively from food. Vitamin B1 deficiency is an under-diagnosed disease because it is less frequently suspected in high income countries. However, its risk factors, like alcohol and malnutrition, are common in the general population. Thiamin deficiency can lead to three clinical entities, Gayet-Wernicke encephalopathy, which can progress to Korsakoff encephalopathy, wet Beriberi and its dry form. These diseases are associated with high mortality and heavy long-term sequelae. Rapid diagnosis enables timely treatment.

Cardiac Dysfunction Due to Thiamine Deficiency after Hemodialysis for Biguanide-related Lactic Acidosis

Biguanide is an ideal drug for the treatment of type 2 diabetes mellitus. When used appropriately, the incidence of lactic acidosis is reported to be very low. Risk factors associated with biguanide-related lactic acidosis include chronic kidney disease, congestive heart failure, alcohol use, severe dehydration, shock, hypoxic states, sepsis, and advanced age. We herein report a case of cardiac dysfunction due to thiamine deficiency after hemodialysis in a patient with suspected biguanide-related lactic acidosis. Patients who develop severe lactic acidosis while taking biguanides should be given a large dose of thiamine without delay, given the possibility of thiamine deficiency as a complication.

Identification of Wernicke Encephalopathy in a Patient Presenting With Altered Mental Status and Dehydration

INTRODUCTION

Providing glucose before thiamine can cause or exacerbate Wernicke encephalopathy, a potentially life-threatening condition associated with a variety of neurological impairments.

CASE PRESENTATION

An emaciated, middle-aged woman with a longstanding history of alcohol abuse and an undifferentiated seizure disorder presented to a local emergency department with altered mental status of unknown duration. Initial labs showed signs of acute kidney injury and she could not tolerate oral intake. Overnight, dextrose-containing maintenance fluids were started. The next day, she had an acute deterioration of mental status. Empiric therapy for Wernicke encephalopathy was begun, resulting in resolution of most of her symptoms over a matter of days.

DISCUSSION

It is generally recommended to administer thiamine treatment prior to glucose in patients with suspected thiamine deficiency. The Caine criteria can assist in the decision to start empiric treatment to prevent delays in thiamine therapy.

CONCLUSION

Wernicke encephalopathy is a disease with high morbidity that is usually treated with the generally benign therapy of thiamine. Given the risk of harm of untreated Wernicke encephalopathy and the benign nature of treatment, clinicians should have a low threshold to provide thiamine therapy.

Visual Disturbances in a Grave's Disease Patient After Sleeve Gastrectomy

Wernicke encephalopathy (WE) is a neuropsychiatric disorder that results from untreated severe thiamine deficiency, frequently described as a triad of ophthalmoplegia, ataxia, and confusion. While this triad is commonly used to describe WE, all three symptoms are observed in less than 20 percent of individuals with this diagnosis. Most commonly, WE is observed in individuals with significant alcohol use and associated malnutrition resulting in thiamine deficiency. However, this condition can also be diagnosed in patients with other sources of malnutrition, and less frequently in hypermetabolic states such as those with hyperthyroidism. Due to its broad clinical presentation and numerous causes, Wernicke encephalopathy can be difficult to diagnose. Diagnosis of WE guides management, as glucose before IV thiamine administration can be detrimental. Therefore, it is essential to understand the complexities of WE. In this paper, we discuss a patient who presented to the emergency department complaining of central vision loss, change in color perception, tinnitus, and difficulty walking two months post gastric sleeve and a recently diagnosed and, possibly inadequately treated, hyperthyroidism. The combination of recent sleeve gastrectomy and hyperthyroidism likely led to thiamine malabsorption and hypermetabolism, resulting in WE.

High proportion of thiamine deficiency in referred cancer patients with delirium: a retrospective descriptive study

BACKGROUND/OBJECTIVES

Recent studies have revealed thiamine deficiency (TD) as a cause of delirium in cancer patients. However, the extent to which Wernicke encephalopathy is present and in what patients is not well understood.

SUBJECTS/METHODS

In this retrospective descriptive study, we investigated referred cancer patients who were diagnosed with delirium by a psycho-oncologist to clarify the proportion of TD, the therapeutic effect of thiamine administration, and the factors involved in its onset.

RESULTS

Among 71 patients diagnosed with delirium by a psycho-oncologist, TD was found in 45% of the patients. Intravenous administration of thiamine led to a recovery in about 60% of these patients. We explored the factors associated with TD using a multivariable regression model with a Markov chain Monte Carlo imputation procedure. We found an association between TD and chemotherapy (adjusted odds ratio, 1.98 [95% confidence interval, 1.04-3.77]); however, there were no significant associations between TD and the other factors we considered.

CONCLUSIONS

TD is not particularly rare in delirium patients undergoing psychiatric consultation. The delirium was resolved in more than half of these patients by intravenous administration of thiamine. Oncologists should consider TD as a cause of delirium in cancer patients. Further prospective study is needed to clarify the relationship between TD and delirium in cancer patients.

Wernicke's encephalopathy - An oddball complication of nephrotic syndrome

Metabolic encephalopathies are a common cause of altered mental status in various states of malnutrition. However, a high index of suspicion is required to recognize them and differentiate Metabolic Disorders from other causes of altered mental status such as infections. A 6-year old with steroid-resistant nephrotic syndrome (NS), peritonitis, and prolonged diarrhea and vomiting, developed a brief episode of altered mental status six days after starting tacrolimus. On imaging, there were features suggestive of Wernicke's encephalopathy and it ruled out other causes of seizure in the given scenario. The child was treated with thiamine supplementation and the changes reversed four weeks after treatment. This is to emphasize that although an uncommonly reported complication of nephrotic state, one should have a high index of suspicion for these metabolic encephalopathies, especially in the setting of malnutrition, where these children are highly predisposed to multivitamin deficiency.

The impact of thiamine deficiency and benfotiamine treatment on Nod-like receptor protein-3 inflammasome in microglia

Thiamine-dependent processes are critical in cerebral glucose metabolism, it is abnormity induces oxidative stress, inflammation and neurodegeneration. Nod-like receptor protein-3 (NLRP3) inflammasome-mediated inflammation is closely related to neurologic diseases and can be activated by oxidative stress. However, the impact of thiamine deficiency on NLRP3 inflammasome activation remains unknown. In this study, we found that NLRP3 inflammasomes were significantly activated in the microglia of thiamine deficiency mice model. In contrast, benfotiamine dampened inflammation NLRP3 mediated in BV2 cells stimulated with LPS and ATP through reducing mitochondrial reactive oxygen species levels and mitigating autophagy flux defect. These data identify an important role of thiamine metabolism in NLRP3 inflammasome activation, and correcting thiamine metabolism through benfotiamine provides a new therapeutic strategy for NLRP3 inflammasome related neurological, metabolic, and inflammatory diseases.

Case of hypoactive delirium precipitated by thiamine deficiency

Thiamine is an essential cofactor in the process of nucleic acid synthesis. Neuronal tissues are especially sensitive to thiamine deficiency, manifesting as Wernicke's encephalopathy (WE). The typical triad of WE, encephalopathy, oculomotor dysfunction and gait ataxia, is only present in less than one-third of the cases. We present the case of a middle-aged man with hypoactive delirium due to presumed thiamine deficiency, who had a prolonged hospital course and a delayed diagnosis of the cause of altered mental status. The presentation of this disorder solely as a decreased level of consciousness is uncommon but has been reported in the literature. It is essential to recognise WE as a treatable condition that may manifest only as a hypoactive delirium. The delay in the diagnosis and treatment may lead to coma and death.

Subclinical thiamine deficiency identified by pretreatment evaluation in an esophageal cancer patient

Despite the fact that both thiamine deficiency (TD) and Wernicke encephalopathy (WE) have been observed to some degree in cancer patients, such cases of TD and/or WE reported to date have all been diagnosed after the initiation of treatment. We here report a case of TD that presented without the commonly accepted triad of WE symptoms based on a total nutritional evaluation prior to the onset of treatment for cancer. The patient was a 71-year-old man with esophageal cancer who was referred to the oncology outpatient clinic for evaluation to determine the treatment plan. Although he did not present with delirium, cerebellar signs, or ocular symptoms, TD was suspected based on a reduction in appetite lasting 2 months as thiamine stores in the body are depleted in as few as 18 days. Blood findings showed a marked decline in serum thiamine level supported, which the diagnosis of TD. This case revealed the existence of a cancer patient with subclinical TD prior to the onset of treatment for cancer. Due to the fact that TD can occur without the characteristic symptoms as in this case, we believe it is important that total nutritional evaluation of cancer patients always be considered.

Wernicke Encephalopathy and Lactic Acidosis in Thiamine Deficiency

Thiamine deficiency can cause encephalopathy (Wernicke) and lactic acidosis. Herein we report a 6-year-old girl on total parenteral nutrition (TPN) who developed lactic acidosis and neurological symptoms due to improper vitamin replacement, which responded to thiamine injection. The MRI brain findings were not typical for Wernicke encephalopathy.

Improving thiamine prescribing at an academic hospital network using the computerized provider order entry system: a cohort study

BACKGROUND

Oral thiamine therapy is frequently prescribed to patients at risk for thiamine deficiency despite recommendations emphasizing the need for high doses of parenteral thiamine to reverse brain thiamine deficits. We evaluated the effect of changes to the computerized provider order entry system on the proportion of prescriptions for parenteral thiamine treatment (primary outcome) and dosages prescribed (secondary outcome) within our academic hospital network.

METHODS

We obtained data from the pharmacy information system recording thiamine prescribed to inpatients at University Health Network hospitals (Toronto, Ontario) before (Jan. 1, 2010, to Dec. 31, 2011) and after (Nov. 21, 2013, to Apr. 30, 2017) changes to the computerized provider order entry system promoting the use of higher dosages (≥ 200 mg) of parenterally administered thiamine. Patients receiving thiamine as part of total parenteral nutrition were excluded from analyses, as thiamine prescribing was automated and unlikely to be affected by the intervention.

RESULTS

A total of 6105 thiamine prescriptions were written for 2907 patients before the intervention and 12 787 thiamine prescriptions for 8032 patients after the intervention. The proportion of prescriptions for parenteral treatment increased from 55.5% (3386/6105) to 92.5% (11 829/12 787) after the intervention (p < 0.001). Increases in prescribing of parenteral thiamine treatment were sustained or enhanced across the 3.4-year observation period and were realized across all hospital services. Prescriptions for higher dosages of thiamine increased from 1.1% (65/6105) to 61.4% (7845/12 787) after the intervention (p < 0.001).

INTERPRETATION

Changes to the computerized provider order entry system were associated with sustained increases in the proportion of prescriptions for high-dose parenteral thiamine therapy. Similar approaches may be leveraged to align prescriber behaviour with well-accepted practice parameters in other areas of medicine.

Establishing a case definition of thiamine responsive disorders among infants and young children in Lao PDR: protocol for a prospective cohort study

INTRODUCTION

Diagnosis of infantile thiamine deficiency disorders (TDD) is challenging due to the non-specific, highly variable clinical presentation, often leading to misdiagnosis. Our primary objective is to develop a case definition for thiamine responsive disorders (TRD) to determine among hospitalised infants and young children, which clinical features and risk factors identify those who respond positively to thiamine administration.

METHODS AND ANALYSIS

This prospective study will enrol 662 children (aged 21 days to <18 months) seeking treatment for TDD symptoms. Children will be treated with intravenous or intramuscular thiamine (100 mg daily for a minimum of 3 days) alongside other interventions deemed appropriate. Baseline assessments, prior to thiamine administration, include a physical examination, echocardiogram and venous blood draw for the determination of thiamine biomarkers. Follow-up assessments include physical examinations (after 4, 8, 12, 24, 36, 48 and 72 hours), echocardiogram (after 24 and 48 hours) and one cranial ultrasound. During the hospital stay, maternal blood and breast-milk samples and diet, health, anthropometric and socio-demographic information will be collected for mother-child pairs. Using these data, a panel of expert paediatricians will determine TRD status for use as the dependent variable in logistic regression models. Models identifying predictors of TRD will be developed and validated for various scenarios. Clinical prediction model performance will be quantified by empirical area under the receiver operating characteristic curve, using resampling cross validation. A frequency-matched community-based cohort of mother-child pairs (n=265) will serve as comparison group for evaluation of potential risk factors for TRD.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from The National Ethics Committee for Health Research, Ministry of Health, Lao PDR and the Institutional Review Board of the University of California Davis. The results will be disseminated via scientific articles, presentations and workshops with representatives of the Ministry of Health.

TRIAL REGISTRATION NUMBER

NCT03626337.

Thiamine Deficiency in a Nondrinker and Secondary Pulmonary Edema after Thiamine Replenishment

A 48-year-old man was brought to our emergency room with acute abdominal pain and systemic edema, indicating acute circulatory failure with lactic acidosis. Furosemide treatment paradoxically worsened the systemic edema and induced confusion. He had no drinking history but hardly ate legumes or meats containing thiamine. Administration of fursultiamine dramatically improved the symptoms and subsequently caused pulmonary edema. Thiamine deficiency may occur in nondrinkers with an unbalanced diet. In this condition, diuretic therapy can worsen the symptoms before thiamine supplementation by promoting the flushing of water-soluble vitamins but is needed for the management of secondary pulmonary edema after thiamine replenishment.

Genetic defects of thiamine transport and metabolism: A review of clinical phenotypes, genetics, and functional studies

Thiamine is a crucial cofactor involved in the maintenance of carbohydrate metabolism and participates in multiple cellular metabolic processes within the cytosol, mitochondria, and peroxisomes. Currently, four genetic defects have been described causing impairment of thiamine transport and metabolism: SLC19A2 dysfunction leads to diabetes mellitus, megaloblastic anemia and sensory-neural hearing loss, whereas SLC19A3, SLC25A19, and TPK1-related disorders result in recurrent encephalopathy, basal ganglia necrosis, generalized dystonia, severe disability, and early death. In order to achieve early diagnosis and treatment, biomarkers play an important role. SLC19A3 patients present a profound decrease of free-thiamine in cerebrospinal fluid (CSF) and fibroblasts. TPK1 patients show decreased concentrations of thiamine pyrophosphate in blood and muscle. Thiamine supplementation has been shown to improve diabetes and anemia control in Rogers' syndrome patients due to SLC19A2 deficiency. In a significant number of patients with SLC19A3, thiamine improves clinical outcome and survival, and prevents further metabolic crisis. In SLC25A19 and TPK1 defects, thiamine has also led to clinical stabilization in single cases. Moreover, thiamine supplementation leads to normal concentrations of free-thiamine in the CSF of SLC19A3 patients. Herein, we present a literature review of the current knowledge of the disease including related clinical phenotypes, treatment approaches, update of pathogenic variants, as well as in vitro and in vivo functional models that provide pathogenic evidence and propose mechanisms for thiamine deficiency in humans.

An Adult Case of Thiamine-Sensitive Megaloblastic Anemia Syndrome Accidentally Diagnosed Myelodysplastic Syndrome

Thiamine-responsive megaloblastic anemia (TRMA) syndrome is a rare disease comprising a classic triad of megaloblastic anemia, diabetes mellitus, and early-onset sensorineural deafness. TRMA can generally be diagnosed in early childhood. Early diagnosis is important to prevent complications that may develop soon. As it is a rare disease, diagnosis may sometimes be difficult. We present a rare case of an adult patient with TRMA who had been mistakenly diagnosed with myelodysplastic syndrome (MDS), whose anemia was corrected only after thiamine treatment was started.

Review of thiamine deficiency disorders: Wernicke encephalopathy and Korsakoff psychosis

Wernicke encephalopathy (WE) and Korsakoff psychosis (KP), together termed Wernicke-Korsakoff syndrome (WKS), are distinct yet overlapping neuropsychiatric disorders associated with thiamine deficiency. Thiamine pyrophosphate, the biologically active form of thiamine, is essential for multiple biochemical pathways involved in carbohydrate utilization. Both genetic susceptibilities and acquired deficiencies as a result of alcoholic and non-alcoholic factors are associated with thiamine deficiency or its impaired utilization. WKS is underdiagnosed because of the inconsistent clinical presentation and overlapping of symptoms with other neurological conditions. The identification and individualized treatment of WE based on the etiology is vital to prevent the development of the amnestic state associated with KP in genetically predisposed individuals. Through this review, we bring together the existing data from animal and human models to expound the etiopathogenesis, diagnosis, and therapeutic interventions for WE and KP.

Thiamine deficiency and cardiovascular disorders

BACKGROUND AND AIM

Thiamine, also known as vitamin B1, functions as a cofactor in the metabolism of carbohydrates and amino acids. Thiamine deficiency has been suggested to be associated with many cardiovascular diseases (CVDs) and risk factors including type 1 and type 2 diabetes (T1D and T2D, respectively), obesity, chronic vascular inflammation, dyslipidemia, heart failure (HF), myocardial infarction (MI) and conduction defects, and depression. The aim of this review was to explore the evidence of thiamine deficiency among subjects with CVDs or risk factors, illustrate the theories explaining the thiamine-CVDs associations, and describe the effect of thiamine supplementation.

METHODS

Human and animal studies were collected from various scientific databases following the PRISMA guidelines without limitation regarding the publication year. Studies investigating the prevalence of thiamine deficiency among patients with CVDs and the effect of thiamine supplementation on their conditions were summarized.

RESULTS AND CONCLUSIONS

Thiamine deficiency could have a role in the development of CVDs. Future studies should focus on the impact of thiamine supplementation on reversing CVDs and risk factors associated with its deficiency.

Pharmacogenomics in diabetes: outcomes of thiamine therapy in TRMA syndrome

AIMS/HYPOTHESIS

Diabetes is one of the cardinal features of thiamine-responsive megaloblastic anaemia (TRMA) syndrome. Current knowledge of this rare monogenic diabetes subtype is limited. We investigated the genotype, phenotype and response to thiamine (vitamin B1) in a cohort of individuals with TRMA-related diabetes.

METHODS

We studied 32 individuals with biallelic SLC19A2 mutations identified by Sanger or next generation sequencing. Clinical details were collected through a follow-up questionnaire.

RESULTS

We identified 24 different mutations, of which nine are novel. The onset of the first TRMA symptom ranged from birth to 4 years (median 6 months [interquartile range, IQR 3-24]) and median age at diabetes onset was 10 months (IQR 5-27). At presentation, three individuals had isolated diabetes and 12 had asymptomatic hyperglycaemia. Follow-up data was available for 15 individuals treated with thiamine for a median 4.7 years (IQR 3-10). Four patients were able to stop insulin and seven achieved better glycaemic control on lower insulin doses. These 11 patients were significantly younger at diabetes diagnosis (p = 0.042), at genetic testing (p = 0.01) and when starting thiamine (p = 0.007) compared with the rest of the cohort. All patients treated with thiamine became transfusion-independent and adolescents achieved normal puberty. There were no additional benefits of thiamine doses >150 mg/day and no reported side effects up to 300 mg/day.

CONCLUSIONS/INTERPRETATION

In TRMA syndrome, diabetes can be asymptomatic and present before the appearance of other features. Prompt recognition is essential as early treatment with thiamine can result in improved glycaemic control, with some individuals becoming insulin-independent.

DATA AVAILABILITY

SLC19A2 mutation details have been deposited in the Decipher database ( https://decipher.sanger.ac.uk/ ).

Wet beriberi with multiple organ failure remarkably reversed by thiamine administration: A case report and literature review

RATIONALE

Circulatory failure, especially with low systemic vascular resistance (SVR), as observed in septic shock, thyrotoxicosis, and anemia, is a particular pattern that should suggest thiamine (vitamin B1) deficiency. The clinical picture of wet beriberi secondary to thiamine deficiency only demonstrates non-specific clinical manifestations. For a diagnosis of wet beriberi, medical history is very important. Interestingly, imprisonment was also found to be related to thiamine deficiency. This article presents a rare case of wet beriberi associated with multiple organ failure (MOF) in a prison patient with years of heavy alcohol consumption.

PATIENT CONCERNS

The patient reported repetitive symptoms of nausea, vomiting, respiratory distress, and palpitations for a period of 1 month; dyspnea and edema for 5 days; and decreased blood pressure and urine volume for 2 days.

DIAGNOSES

The heart failure patient had a history of dietary deficiency. Right heart catheterization showed high cardiac output (CO) and low SVR. Measurement of serum thiamine concentration was low. The most important factor was that the hemodynamic indices were remarkably reversed by thiamine administration.

INTERVENTIONS

The patient started treatment with thiamine (100 mg) by intramuscular injection, together with basic supportive care.

OUTCOMES

The hemodynamic indices improved within 12 hours after thiamine administration. Echocardiographic examinations revealed right ventricular function improvement within a few days, which were normal within a month.

LESSONS

A diagnosis of wet beriberi should be considered for a prison patient who has unexplained heart failure, lactic acidosis, and/or MOF. Moreover, the patient should be empirically given thiamine administration without delay.

Wet Beriberi Associated with Hikikomori Syndrome

Wet beriberi, characterized by high cardiac output with predominantly right-sided heart failure and lactic acidosis, is a disease caused by thiamine deficiency, and is rarely seen in modern society. However, patients with social withdrawal syndrome, also known as hikikomori syndrome, may be a new population at risk of thiamine deficiency. Hikikomori syndrome, first recognized in Japan, is becoming a worldwide issue. A 39-year-old Japanese patient was brought to our hospital, with a 3-week history of progressive shortness of breath and generalized edema. The patient had right-sided high-output heart failure, lactic acidosis, and Wernicke-Korsakoff syndrome. Because of his history of social isolation, we diagnosed hikikomori syndrome according to the Japanese government's definition, which is as follows: lifestyle centered at home; no interest or willingness to attend school or work; persistence of symptoms beyond 6 months; and exclusion of other psychiatric and developmental disorders. Considering his diagnosis of hikikomori syndrome and social isolation, we suspected malnutrition, particularly thiamine deficiency, and successfully treated him. Clinicians should be aware of the potential risk of thiamine deficiency associated with hikikomori syndrome and initiate thiamine replacement in cases of high-output heart failure associated with lactic acidosis.

Wernicke encephalopathy in a patient after liver transplantation: A case report

Wernicke encephalopathy (WE) is an acute neurological disorder resulting from vitamin B1 deficiency, which is common in chronic alcoholism and is rare in acute liver failure. So far, there are 2 cases of WE reported after liver transplantation. Here, we report a case of a 45-year-old nonalcoholic male patient who developed psychiatric and neurological disturbance 15 d after receiving orthotopic liver transplantation because of hepatitis B-related cirrhosis and portal hypertension. Brain magnetic resonance imaging (MRI) showed symmetric high-signal intensities in the periaqueductal area. The patient was diagnosed with WE and given intravenous high-dose vitamin B1 immediately. His neurological disturbance resolved in 7 d after receiving the vitamin B1. Brain MRI after 5 mo showed nearly complete recovery. Most WE cases may be misdiagnosed in patients after liver transplantation, and we should pay more attention to its onset.

Epileptic seizures in nonalcoholic Wernicke's encephalopathy: a case report and literature review

Wernicke encephalopathy (WE) is characterized by eye signs, cerebellar dysfunction, and confusion. Epileptic seizures are rare in nonalcoholic WE. We reviewed the clinical, laboratory, radiological, and prognostic characteristics of nonalcoholic WE accompanied by epileptic seizures. We reported 1 case and searched similar cases using PubMed, WoK, Ovid, and Embase. WE was diagnosed according to dietary deficiencies, clinical symptoms and brain magnetic resonance imaging (MRI). We reviewed 13 patients (median age, 27 years; 5 men) with clear histories of thiamine deficiency and symptoms of typical WE. The type of epileptic seizures reported in the 13 cases reviewed was generically reported as seizures or convulsions in 4 patients; 7 patients had generalized tonic-clonic seizures, 1 partial seizure, and 1 generalized convulsive status epileptics. Two patients had epileptic seizures as the first symptom of WE. Laboratory tests mainly indicated metabolic acidosis and electrolyte disturbances. Electroencephalography may present as normal patterns, increased slow waves or epileptic discharge. Six patients had cortical lesions on brain MRI. These lesions were usually diffuse and band-like, and sometimes involved all lobes either symmetrically or asymmetrically, with the frontal lobe as the most susceptible area. All cortical lesions were accompanied by non-cortical lesions typical of WE. Brain MRI abnormalities, after thiamine treatment, mostly disappeared on follow-up MRIs. The patients had good prognoses. Only 1 patient had repeated seizures, and there were no comas or deaths. Patients with nonalcoholic WE accompanied by seizures are young and generally have good prognoses. Most patients experienced generalized convulsive seizures, which may have been related to abnormal cerebral cortical metabolism due to subacute thiamine deficiency.

Beta cell function and clinical course in three siblings with thiamine-responsive megaloblastic anemia (TRMA) treated with thiamine supplementation

Three siblings with thiamine-responsive megaloblastic anemia (TRMA) with a homozygous c.454delGGCATinsAT mutation in SLC19A2 are described. The index case presented at 14 months' old with severe non-ketotic hyperglycemia, dehydration, seizures and sinovenous thrombosis. She was started on insulin and developed sensorineural hearing loss around 2 years old. Two siblings were found to have the same mutation and were started on thiamine. One sibling developed transient hyperglycemia after several years of thiamine supplementation of 12 mg/kg that resolved with an increased thiamine dose (23 mg/kg). A younger sibling continues to remain diabetes-free on thiamine (24 mg/kg). The clinical course in this family suggests that there is an effect of thiamine on pancreatic beta cell function in patients with TRMA given the resolution of impaired fasting glucose with increasing thiamine dose in one sibling and the lack of diabetes to date in the siblings that were treated early with thiamine.

The Dramatic Recovery of a Patient with Biguanide-associated Severe Lactic Acidosis Following Thiamine Supplementation

Biguanides are a drug of choice for the treatment of type 2 diabetes mellitus. Although they can cause lactic acidosis in susceptible patients with predisposing risk factors, the incidence of lactic acidosis is reported to be very low when they are used properly. We herein present a case of biguanide-associated severe lactic acidosis complicated with thiamine deficiency that was provoked without predisposing factors for thiamine deficiency. Diabetic patients taking biguanide may be predisposed to thiamine deficiency, even when there is no evidence of risk factors, and the high-dose administration of thiamine may be essential in the treatment of this otherwise under-recognized disorder.

[Wernicke encephalopathy and dry beriberi; late complications after bariatric surgery performed on a patient with a psychiatric history]

A 38-year-old woman was admitted in a psychiatric hospital because of memory disorders. Dry beriberi and Korsakoff's syndrome, as a late neuropsychiatric manifestation of Wernicke's encephalopathy, were established. The beriberi symptoms decreased slowly, but the patient's memory impairments persisted. These clinical features were caused by a thiamine deficiency. Gastric bypass surgery is associated with an increased risk of thiamine deficiency. Excessive alcohol consumption and poor compliance with vitamin deficiency treatment both contributed to the rapid onset of these disorders. The case we describe demonstrates how important it is that patients who have undergone bariatric surgery are prescribed the correct vitamin supplements and that the treatment is continued for an appropriate period of time; this treatment is particularly important in the case of patients who are also suffering from an comorbid alcohol-related disorder.

Reversal of Refractory Congestive Heart Failure after Thiamine Supplementation: Report of a Case and Review of Literature

Patients with refractory heart failure comprise a very important subgroup of patients with congestive heart failure. Before assuming that this condition simply reflects advanced, perhaps terminal, myocardial dysfunction, potentially reversible factors should be sought carefully. We describe a 58-year-old Hispanic man with a diagnosis of idiopathic dilated cardiomyopathy who presented with symptoms of severe congestive heart failure, glossitis, and peripheral neuropathy. His hemodynamic profile was characterized by refractory low-output cardiac failure and decreased vascular resistance. Thiamine deficiency was documented by a high thiamine pyrophosphate effect. His clinical condition was quickly reversed with thiamine administration. This response to thiamine administration supports the diagnosis and indicates that thiamine deficiency may play an important etiologic role in the deterioration of cardiac function in some patients with congestive heart failure.

The Long-Term Cost to the UK NHS and Social Services of Different Durations of IV Thiamine (Vitamin B1) for Chronic Alcohol Misusers with Symptoms of Wernicke's Encephalopathy Presenting at the Emergency Department

BACKGROUND

Wernicke's encephalopathy (WE) is an acute neuropsychiatric condition caused by depleted intracellular thiamine, most commonly arising in chronic alcohol misusers, who may present to emergency departments (EDs) for a variety of reasons. Guidelines recommend a minimum 5-day course of intravenous (IV) thiamine in at-risk patients unless WE can be excluded.

OBJECTIVE

To estimate the cost impact on the UK public sector (NHS and social services) of a 5-day course of IV thiamine, vs a 2- and 10-day course, in harmful or dependent drinkers presenting to EDs.

METHODS

A Markov chain model compared expected prognosis of patients under alternative admission strategies over 35 years. Model inputs were derived from a prospective cohort study, expert opinion via structured elicitation and NHS costing databases. Costs (2012/2013 price year) were discounted at 3.5 %.

RESULTS

Increasing treatment from 2 to 5 days increased acute care costs but reduced the probability of disease progression and thus reduced the expected net costs by GBP87,000 per patient (95 % confidence interval GBP19,300 to GBP172,300) over 35 years.

CONCLUSIONS

Increasing length of stay to optimize IV thiamine replacement will place additional strain on acute care but has potential UK public sector cost savings. Social services and the NHS should explore collaborations to realise both the health benefits to patients and savings to the public purse.

[Thiamine deficiency caused lactic acidosis in patient with malnutrition]

A case is presented, where preoperative malnutrition was the most likely explanation to elevated lactate levels during and after surgery. Poor circulation, a common cause of elevated lactate during surgery, was excluded. The elevated lactate levels were normalized after intravenous administration of thiamine. Thiamine is an essential cofactor in carbohydrate metabolism for energy production. Thiamine deficiency is common among ICU patients. Clinical suspicion of malnutrition should lead to early parenteral administration of thiamine without specific laboratory confirmation of thiamine deficiency.

Thiamine prescribing practices within university-affiliated hospitals: a multicenter retrospective review

BACKGROUND

Patients with suspected thiamine deficiency should receive treatment with parenteral thiamine to achieve the high serum thiamine levels necessary to reverse the effects of deficiency and to circumvent problems with absorption common in the medically ill.

OBJECTIVE

To quantify rates of parenteral administration of thiamine across university-affiliated hospitals and to identify factors associated with higher rates of parenteral prescribing.

DESIGN

Multicenter, retrospective observational study of thiamine prescriptions.

METHODS

Prescriptions for thiamine were captured from computerized pharmacy information systems across participating centers, providing information concerning dose, route, frequency, and duration of thiamine prescribed from January 2010 to December 2011.

SETTING

Fourteen university-affiliated tertiary care hospitals geographically distributed across Canada, including 48,806 prescriptions for thiamine provided to 32,213 hospitalized patients.

RESULTS

Parenteral thiamine accounted for a statistically significant majority of thiamine prescriptions (57.6%, P < 0.001); however, oral thiamine constituted a significant majority of the total doses prescribed (68.4%, z = 168.9; P < 0.001). Protocols prioritizing parenteral administration were associated with higher rates of parenteral prescribing (61.3% with protocol, 45.8% without protocol; P < 0.001). Patients admitted under psychiatry services were significantly more likely to be prescribed oral thiamine (P < 0.001).

CONCLUSIONS

Although parenteral thiamine accounted for a statistically significant majority of prescriptions, oral thiamine was commonly prescribed within academic hospitals. Additional strategies are needed to promote parenteral thiamine prescribing to patients with suspected thiamine deficiency.