Endocrinology: Acute Hypercalcaemia Flashcards
Outline the pathophysiology of hypercalcaemia.
Normal = 2.12-2.65mmol/L
Hyperparathyroidism = increased PTH = increased release from bone stores = high Ca
Malignancy = bone break down and release of Ca
Sarcoidosis = uncontrolled synthesis of 1,25-dihydroxyvitamin D3 by macrophages = increased absorption of calcium in the intestine
Outline the aetiology of hypercalcaemia.
Malignancy = bone mets, myeloma, PTHrP
Primary hyperparathyroidism
Sarcoidosis
Vit D intoxication
Thyrotoxicosis
Kidney failure
What are the signs and symptoms of hypercalcaemia?
Abdo pain
Vomiting
“stones, bones, abdominal groans, thrones and psychiatric overtones”
Constipation
Polyuria
Depression
Anorexia, weight loss
Weakness
HTN
Confusion
Renal stones
Renal failure
How would you investigate hypercalcaemia?
PTH = increased indicates hyperparathyroidism
US parathyroid glands
CXR = ? sarcoidosis
Malignancy = decreased albumin, decreased Cl, alkalosis, decreased K, increased alk phos, myeloma (bence-jones), PSA, CT CAP
Bloods = U+Es, vit D, alk phos, phosphate
How would you manage hypercalcaemia?
Correct dehydration = IV 0.9 saline
Bisphosphonates = prevent bone resorption by inhib osteoclasts (need close monitoring - can give Ca in hypoCa)
Malignancy = chemotherapy
Sarcoidosis = steroids
When pt is fully rehydrated furosemide can be used to promote renal excretion of Ca
What are the complications of hypercalcaemia?
Osteoporosis
Kidney stones
Confusion, dementia
What malignancies typically cause hypercalcaemia and what are the mechanisms?
Primary (by spreading to bone) = breast, kidney, lung, thyroid, prostate, ovary
Bone related = multiple myeloma, leukaemia
Increased bone turnover releasing Ca into the bloodstream
What drugs can help lower calcium? What is their mechanism of action?
Bisophosphonates = prevent bone resorption by inhib osteoclasts
Calcitonin (miacalcin) = inhibits osteoclasts, increasing excretion
Calcimimetics = controls overactive parathyroid
Prednisone = inhibits vit D metabolism
