L2- Calcium Homeostasis, Hyper and Hypocalcaemia Flashcards
What is primary hyperaldosteronism?
One of the functions of your adrenal glands is to produce a hormone called aldosterone that plays an active role in your blood pressure. It does this by maintaining the balance of sodium, potassium, and water in your blood. Hyperaldosteronism is an endocrine disorder that involves one or both of your adrenal glands creating too much of a hormone called aldosterone. This causes your body to lose too much potassium and retain too much sodium, which increases water retention, blood volume, and blood pressure.
Who would you screen for primary hyperaldosteronism?
- people with hypokalaemia (low potassium)
- resistant hypertension (tried 3 drugs)
- younger people
What tests would you do to screen for and then confirm a diagnosis of primary hyperaldosteronism?
suppressed renin, normal/ high aldosterone.
confirm with an oral or IV Na+ suppression test.
Would then need to work out the aetiology by ct or metomidate PET scan.
If a patient has primary hyperaldosteronism caused by bilateral hyperplasia, what 2 drugs could you use to treat this with?
Spironolactone
Eplerinone
What is the name of a rare type of tumour of the adrenal gland?
phaeochromocytoma.
How would phaeochromocytoma present?
spells of headache, sweating, pallor, palpitation, anxiety.
hypertension
family history
What are the 3 genetic conditions associated with phaeochromocytoma?
neurofibromatosis type 1 (NF1) -Neurofibromatosis type 1 (NF1) is a genetic condition that causes tumours to grow along your nerves. The tumours are usually non-cancerous (benign).
Multiple endocrine neoplasia type 2 (MEN 2) -Multiple endocrine neoplasia type 2 (MEN2) is a hereditary condition associated with 3 primary types of tumors: medullary thyroid cancer, parathyroid tumors, and pheochromocytoma. MEN2 is classified into subtypes based on clinical features.
Von Hippel- Lindau syndrome- Von Hippel-Lindau syndrome (VHL) is a hereditary condition associated with tumors arising in multiple organs. Tumors in VHL include hemangioblastomas, which are blood vessel tumors of the brain, spinal cord, and eye.
How would you test for phaeochromocytoma?
24 hours urine test, looking for high levels of normetanephrines (metabolite of noradrenaline) and metanephrines (metabolite of adrenalin) and 3 methoxytyromine (metabolite of dopamine).
plasma test to look for noradrenalin, adrenalin and metanephrines.
What drugs would you use to manage phaeochromocytoma?
Alpha blockers- phenoxybenzamine, doxazocin.
Betablockers- propranolol.
What are the 2 physical signs that can be used to detect hypocalcaemia?
Tousseau’s sign- cuff, hand spasm
Chvostek’s sign- tapping the facial nerve.
How does the body increase calcium levels?
The chief cells in the parathryoid gland release parathyroid hormone which increases serum clacium levels by:
How does the body lower calcium levels?
The calcium-sensing receptor (CaSR) detects the calcium levels are too high and stimulates the uptake of calcium by the parathryoid chief cell.
