Cardiology Flashcards
(12 cards)
How long does it take to develop thiamine deficiency?
4 weeks
What are the food sources of thiamine? (7)
1) Yeast
2) Organ meat
3) Pork
4) Beef
5) Legumes
6) Whole grains
7) Nuts
What is the function of thiamine? (3)
1) Coenzyme in decarboxylation of alpha keto acids and branch chain amino acids. TCA cycle- pyruvate to Acetyl CoA
2) Thiamine pyrophosphate coenzyme for transketolase reaction for conversion of hexose and pentose phosphates
3) Peripheral nerve conduction
What leads to thiamine deficiency?
1) Poor intake
- Processed foods
- Alcoholism
- TPN
2) Poor absorption
- Bariatric surgery
- Malabsorption syndrome
- Drugs: metformin, verapamil
3) Increased losses
- Hyperemesis
- Diuretic use
- Haemodialysis
4) Increased utilization
- Hyperthyroidism
- Pregnancy
How does alcohol lead to thiamine deficiency? (3)
1) Decreased intestinal absorption
2) Decreased synthesis of thiamine pyrophosphate
3) Increased urinary excretion
In alcoholism with carbohydrate repletion
Always replace thiamine to prevent acute thiamine deficiency and lactic acidosis
How does wet beri beri present?
1) Tachycardia
2) High output congestive heart failure
3) Peripheral oedema
4) Peripheral neuritis
How does dry beri beri present?
- Symmetric motor and sensory peripheral neuropathy
- Decreased reflexes
How does Wernickes Encephalopathy present?
1) Horizontal nystagmus
2) Ophthalmoplegia
3) Cerebellar ataxia
4) Mental impairment
How does Wernicke Korsakoff Syndrome present?
- Same as Wernickes Encephalopathy
- Memory loss
- Psychotic Confabulation
Treatment of thiamine deficiency?
Acute
- 200mg IV tds until no further improvement
- Supplement other deficiencies
- In WKS 500mg IV tds for 2 days then 250mg IV dly for 3 days
All patients
- Continue thiamine 100mg dly
Mechanisms of high output failure in beri berj
- Decreased Systemic vascular resistance
- Increased blood volume
- Decreased myocardial contractility
