Calcium & Vitamin D Flashcards
What electrolyte imbalance could be causing these symptoms?
Bone pain, renal stones, groans, psychic moans, abdominal pain, vomiting, polyuria, polydipsia, depression, anorexia, weight loss, tiredness, hypertension, confusion.
Hypercalcemia
What is the abnormality present on an ECG in someone with hypercalcemia?
Short QT complex
What are the causes of hypercalcemia?
- Malignancy from bone metastases, myeloma, PTHrP
- Primary hyperparathyroidism
- Sarcoidosis, FHH
What are the typical blood test results in hypercalcemia?
- High phosphate, ALP indicates malignancy
2. High PTH indicates hyperparathyroidism
What is the treatment for hypercalcemia?
- IV saline
- Bisphosphonate - pamidronate
- Chemotherapy in malignancy, prednisolone in sarcoidosis
What electrolyte imbalance could be causing these symptoms?
Cramps, numbness, paraesthesia, spasms, seizures, Trousseau’s sign, Chvostek’s sign.
Hypocalcaemia
What is Trousseau’s sign and what does it indicate?
- Blood pressure cuff inflated, causes spasm in hand at wrist, MCP, IP
- Hypocalcaemia
What is Chvostek’s sign and what does it indicate?
- Tap facial nerve anterior to ear, contraction of ipsilateral facial muscles.
- Hypocalcaemia
What are the causes of hypocalcaemia if phosphate is high?
CKD, low Mg, hypoparathyroidism
What are the causes of hypocalcaemia if phosphate is normal or low?
Vitamin D deficiency or osteomalacia
What is the treatment for hypocalcaemia?
- Mild - oral calcium
- CKD - calcitriol, phosphate binders
- Severe - 10ml 10% calcium gluconate
What is the underlying histology in primary hyperparathyroidism?
80% solitary adenoma, 20% hyperplasia of the gland.
What signs/symptoms might someone with primary hyperparathyroidism have?
- Hypercalcaemia - weak, polydipsia, polyuria, renal stones, abdominal pain, pancreatitis, duodenal ulcers.
- Bone resorption - pain, fractures, osteopenia, osteoporosis
What are the findings of investigations in primary hyperparathyroidism?
- High calcium and parathyroid hormone
- Low phosphate, increased ALP from bone
- Raised 24-hour urinary calcium excretion
What is the treatment of primary hyperparathyroidism?
- Mild - increase fluid intake
2. Severe - removal of adenoma
What is the effect of secondary hyperparathyroidism on serum calcium and parathyroid hormone?
- Low calcium
2. Raised PTH
What are the causes and treatment for secondary hyperparathyroidism?
- Causes - low vitamin D, CKD
2. Treatment - phosphate binders, vitamin D
What is the effect of tertiary hyperparathyroidism on serum calcium and parathyroid hormone?
- High calcium
2. Very high PTH
What is the main cause of tertiary hyperparathyroidism
Often occurs after prolonged secondary hyperparathyroidism (seen in CKD)
What is malignant hyperparathyroidism?
- Parathyroid hormone releasing peptide produced by squamous cell lung cancer, breast cancer, and renal cell carcinoma.
- PTH is low, PTHrP is raised
What causes primary hypoparathyroidism, what is the effect on calcium and phosphate, and how is it treated?
- Low PTH due to gland failure - autoimmune, congenital
- Low calcium, high/normal phosphate
- Calcium, calcitriol
What are the causes of secondary hypoparathyroidism?
Radiation, surgery, hypomagnesaemia.
What is pseudohypoparathyroidism, what is the effect on calcium and parathyroid hormone, and how is it treated?
- Failure of cell to respond to PTH - short 4th and 5th metacarpals, round face, short stature, reduced IQ.
- Low calcium, raised/normal PTH
- Calcium and calcitriol
What is the difference between pseudohypoparathyroidism and pseudopseudohypoparathyroidism?
Pseudopseudohypoparathyroidism is the same as pseudohypoparathyroidism but has normal biochemistry.
