Calcium And Parathyroid Hormone 07.12.23

Question 1

Parathyroid hormone actions

Answer 1

Slide 4

Question 2

What Does a small change in serum calcium result in a large or small change in PTH?

Answer 2

Large - slide 8

Question 3

Hypocalcaemia - what two measurements in the blood are low?

Answer 3

Low total serum calcium and low ionised calcium

Question 4

What is the equation for corrected calcium?

Answer 4

Total serum calcium + 0.02 * (40 - serum albumin)

Question 5

Consequences of hypocalcaemia

Answer 5

Parasthesia (pins and needles)
Muscle spasm (hands and feet, larynx, premature labour)
Seizures
Basal ganglia calcification
Cataracts
ECG abnormalities (long QT interval)

Question 6

What are the 2 signs used to check for hypocalcaemia

Answer 6

Chvostek’s sign (tap over the facial nerve, look for spasm of facial muscles)

Trousseau’s sign (inflate the blood pressure cuff to 20mm Hg above systolic for 5 minutes)

Question 7

What are the common symptoms and consequences of hypercalaemia?

Answer 7

Thirst (polyuria)
Nausea
Constipation
Confusion —> coma

Renal stones
ECG abnormalities (short QT)

Question 8

Causes of hypercalcaemia

Answer 8

Malignancy —> bone mets, myeloma, PTHrP, lymphoma
Primary hyperparathyroidism

Question 9

What % of hypercalcaemic cases are caused by malignancy or primary hyperparathyroidism

Answer 9

90%

Other 10% is thiazides, thyrotoxicosis, sarcoidosis, familial hypocalciuric/benign hypercalcaemia, immobilisation, milk-alkali, adrenal insufficiency, phaeochromocytoma

Question 10

Consequences of primary hyperparathyroidism

Answer 10

Bones (osteitis fibrosis cystica, osteoporosis)
Kidney stones
Psychic groans (confusion)
Abdominal moans (constipation, acute pancreatitis)

Question 11

In cases of primary hyperparathyroidism, 80% are due to what

Answer 11

Single benign adenoma

Question 12

In cases of primary hyperparathyroidism, 15-20% are due to what

Answer 12

Four gland hyperplasia

Question 13

See parathyroid handout (word doc)