Thiamine Deficiency

OVERVIEW

  • Thiamine Deficiency = Beri-Beri (wet or dry)
  • lack of thiamine pyrophosphate or Vitamin B1
  • can progress slowly or quickly and be fatal
  • water-soluble vitamin
  • limited storage in body (30mg)
  • stores of thiamine last around 1 month

ACTIONS

  • acts as a co-enzyme in carbohydrate metabolism through the decarboxylation of alpha ketoacids
  • co-enzyme for transketolase in pentose monophosphate pathway (formation of glucose)
  • co-enzyme for conversion of pyruvate into acetyl-CoA (if blocked leads to lactate production)

CAUSES

  • inadequate intake (alcoholics, diet, starvation)
  • decreased absorption (intestinal disease, alcoholism, malnutrition, gastric bypass, folate deficiency)
  • increased consumption (hyperthyroidism, pregnancy, lactation, fever)
  • increased depletion (diarrhoea, diuretics, dialysis)
  • severe liver disease (impairs its use)
  • folate deficiency (thiamine regenerated via proton donation from NADH -> folate required to have enough dihydrofolate reductase to regenerate NADH)

CLINICAL FEATURES

Dry Beri-Beri

  • bilateral, peripheral sensory and motor neuropathy with weakness and hyporeflexia

Wernicke encephalopathy

  • altered mental state
  • ophthalmoplegia with horizontal nystagmus
  • ataxia and vestibular dysfunction
  • fever and vomiting may be present

Korsakoff encephalopathy

  • progressive mental impairment characterised by short-term memory loss and confabulation
  • chronic and irreversible

Wet Beri-Beri

  • tachycardia
  • vasodilation
  • high cardiac output
  • fluid overload
  • cardiac failure

INVESTIGATIONS

  • lactic acidosis
  • echocardiography
  • blood thiamine, pyruvate, alpha-ketoglutarate and glyoxylate levels
  • thiamine loading test erythrocyte transketolase activity preloading and post-loading is the best indicator of thiamine deficiency (look for  increase of >5% in enzyme activity
  • urinary thiamine and methylglyoxal

MANAGEMENT

Prevention and treatment of thiamine deficiency

  • thiamine 100 mg orally daily

Prevention and treatment of thiamine deficiency in severe alcoholics

  • thiamine 100 to 200 mg IV daily for 3 days
  • then thiamine 100 mg orally daily

Treatment of Wernicke encephalopathy

  • thiamine 500 mg IV infusion over 30 minutes, 3 times daily for 3 days
  • then thiamine 250 mg IV or IM, daily for 3 to 5 days or until clinical improvement ceases

Supportive care monitoring

  • optimise nutrition
  • treat underlying cause, e.g. chronic alcoholism with liver disease
  • treat complications e.g. heart failure

SHOULD THIAMINE BE GIVEN BEFORE GLUCOSE IN HYPOGLYCAEMIA?

  • Traditional teaching is to never treat hypoglycaemia prior to giving thiamine due to risk of precipitating Wernicke encephalopathy – this is a myth – never delay treatment of hypoglycemia
  • The concern is that an excessive carbohydrate load will lead to the build up of toxic metabolites when the activity of these enzymes is reduced because of thiamine deficiency
  • There are no reported instances of a single bolus of glucose precipitating Wernicke encephalopathy
  • Prolonged carbohydrate administration (e.g. from total parenteral nutrition) without thiamine supplementation has been reported to precipitate Wernicke’s encephalopathy

References and Links

LITFL

  • Critical Care Drug Manual — Thiamine
  • Toxicology Conundrum 037 — Hypoglycaemia, but how? (includes discussion of need to replace thiamine prior to treatment)

Journal articles and textbooks

  • Donnino MW, Vega J, Miller J, Walsh M. Myths and misconceptions of Wernicke’s encephalopathy: what every emergency physician should know. Ann Emerg Med. 2007 Dec;50(6):715-21. PMID: 17681641
  • Hack JB, Hoffman RS. Thiamine before glucose to prevent Wernicke encephalopathy: examining the conventional wisdom. JAMA. 1998 Feb 25;279(8):583-4. PMID: 9486750

CCC 700 6

Critical Care

Compendium

Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also the Innovation Lead for the Australian Centre for Health Innovation at Alfred Health and Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of two amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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