Flashcards in Calcium homeostasis and metabolism Deck (28):
How does hypocalcaemia present?
Paraesthesia (fingers, toes, perioral)
Which two signs suggest hypocalaemia?
Chovsteks (facial nerve)
Trousseau (carpopedal spasm)
What is a sign of hypocalaemia on an ECG?
Prolonged QT interval
What are the causes of hypocalcaemia?
Vitamin D deficiency (rickets, osteomalacia)
Chronic renal failure
How is acute hypocalcaemia?
IV calcium gluconate
What are the causes of hypoparathyroidism?
What is the management of chronic hypocalcaemia?
Vitamin D - 1alpha calcidol (tablet) or cholecalciferol (injection)
How does hypomagnesaemia cause hypocalcaemia?
Magnesium is essential for calcium release from cells >
Intracellular calcium is high >
PTH release inhibited >
Skeletal and muscle receptors less sensitive to calcium
How is hypomagnesaemia treated?
Calcium and magnesium replacement
What are the causes of hypomagnesaemia?
Medication (thiazides, PPI)
What is pseudohypoparathyroidism?
Genetic dysfunction of G protein Gs alpha subunit causing PTH resistance
How does pseudohypoparathyroidism present?
Bone abnormalities/McCune Albright
What is pseudo-pseudohypoparathyroidism?
Pseudohypoparathyroidism but with normal calcium levels
Can you change between pseudo-pseudohypoparathyroidism to pseudohypoparathyroidism?
Where do humans get their vitamin D from?
The sun and their diet
How do the terms rickets and osteomalacia differ?
Softening of the bones
Rickets - children
Osteomalacia - adults
How does vitamin D deficiency arise?
Lack of sunlight
Chronic renal failure
How does osteomalacia present?
Dental defects (caries)
What x-ray feature is associated with vitamin D deficiency?
What deficiency does chronic renal failure cause?
Vitamin D deficiency --> secondary hypoparathyroidism
What changes to vitamin D does chronic renal failure cause?
25 OH vit D may be normal or high
1,25 OH vit D will be low
How should chronic renal failure be treated in terms of vitamin D correction?
Titrate levels of vitamin D to match PTH
Phosphate binders (to get rid of elevated blood phosphate)
What are the biochemical results of someone with UV related vitamin D deficiency?
High alk phosphate
Low vitamin D
What are the long term risks of vitamin D deficiency?
What is the treatment for chronic vitamin D deficiency?
Vitamin D3 tablets
Adcal D3 (calcium + vit D)
What is X-linked hypophosphataemia? What other name does it go by?
Genetic mutation causing decreased phosphate reabsorption and thus rickets
Vitamin D resistant rickets
What is the biochemical profile of someone with hypophosphataemia?
High vitamin D