Hypo/hypercalcemia Flashcards
What is role of calcium?
Co-factor in coagulation
Skeletal mineralisation
Membrane stabilisation
Neuronal conduction
Explain homeostasis of calcium?
Decreased serum calcium cause increase PTH
Increased PTH - increase bone resorb, increase Ca absorb on kidney and SI
Role of PTH?
- Kidney - increase Ca reabsorb increase hydroxylation of vitamin D
- Bone- increase bone remodelling reabsorb >form
- Intestine - no direct effect - increase Ca absorb due increase hydroxylated vit D
What is calcium homeostasis an example of?
Negative feedback
What is hypocalcemia?
Low serum albumin = low total serum calcium
Need to use corrected calcium levels to diagnose
Cause hypocalcaemia?
Vit D deficiency, osteomalacia
Hypoparathyroidism
Effect and consequence hypocalcaemia?
Effect: renal failure, Mg deficiency, acute pancreatitis
Consequence: muscle spasm, parathesia, dental hypoplasia, ECG abnormalities
Clinical signs seen in hypocalacemia?
Chovestek’s sign - look for spasm of facial nerve
Trousseau’s sign - inflate cuff will get hand clenched
What would you expect to see in vitamin D deficiency?
Decrease calcium - increased PTH
Decreased phosphate
Appropriate
What would you expect to see in hypoparathyroidism?
Decrease Ca, PTH and increased phosphate
Inappropriate
What would you expect to see in pseudohypoparathyroidsim?
Decreased calcium, increased PTH, increased phosphate
Appropriate
Caused by resistance to PTH
Management hypoparathyroidism?
Asymptomatic: oral calcium supplement AdCal, vit D if deficient
Severe: calcium gluconate
What causes hypercalcaemia?
Malignancy, diuretics, adrenal sufficiency
What could cause false diagnosis of hypercalcemia?
Touriquet on too long
Old and haemolysed sample
What would you see in malignancy causing hypercalcemia?
Increased Ca, decreased PTH
Appropriate
