Calcium regulation

Question 1

PTH is secreted from what type of cell?

Answer 1

Chief cells of the parathyroid hormone which have calcium and vit d receptors

Question 2

What are the actions of PTH?

Answer 2

Activates osteoclasts, acts on kidneys to stimulate reabsorption of calcium, stimulates activation Vit D

Question 3

Draw the vitamin d activation pathway.

Answer 3

Question 4

What are the causes for hypercalcaemia?

Answer 4

C- Calcium supplementation

H- Hyperparathyroidism

I- Iatrogenic (thiazides)

M- Milk alkali syndrome

P- Paget disease of the bone

A- Acromegaly and Addisons disease

N- Neoplasia

Z- Zollinger Ellison syndrome

E- Excessive vit A

E- Excessive vit D

S- Sarcoidosis

Question 5

What are the signs and symptoms of acute hypercalcaemia?

Answer 5

Renal - polyuria and polydipsia

Gastrointestinal- anorexia, vomiting, constipation, abdominal pain

CNS- confusion, lethargy, depression

Question 6

What are the signs and symptoms of chronic hypercalcaemia?

Answer 6

Renal - polyuria, polydipsia, stones

Gastrointestinal- anorexia, vomiting, constipation, abdominal pain

CNS- confusion, lethargy, depression

Bone pain, fracture

Question 7

What is the management of hypercalcaemia?

Answer 7

6L 0.9% Saline over 24 hours

IV bisphosphonate (Zolendronate 4mg).

If the pt is resistant to bisphosphonates then they should receive Im calcitonin or PO steroids

Question 8

What are the causes of hypocalcaemia?

Answer 8

Acute pancreatitis

Hypoparathyroidism

Question 9

What condition can chronic hypocalcaemia lead to?

Answer 9

Osteomalacia

Question 10

What are the signs and symptoms of hypocalcaemia?

Answer 10

Bone and muscle pain

Proximal myopathy

Neuromuscular irritability- parasthesia, dystonia, anxiety, tetany, convulsions, Trousseau and Chvostek’s signs

Question 11

Calcium>3 is almost always what?

Answer 11

Malignancy

Question 12

High calcium with low phosphate is indicative of what?

Answer 12

Hyperparathyroidism

Question 13

High calcium with high phosphate could be which 4 things?

Answer 13

Myeloma, Vitamin D excess, bony malignancy, sarcoidosis

Question 14

High calcium with high ALP could be which 3 things?

Answer 14

Bone metastasis, sarcoidosis, lithium toxicity

Question 15

High calcium with high PTH indicates what? What 3 conditions can cause this?

Answer 15

Parathyroid overactivity.

Hyperparathyroidism, familial hypocalcuric hypercalcemia, lithium toxicity

Question 16

What ECG changes are present in hypercalcaemic patients?

Answer 16

Short QT intervals

Question 17

What are Trosseau and Chvosteks signs?

Answer 17

• Chvostek’s sign is the twitching of the facial muscles in response to tapping over the area of the facial nerve.
• Trousseau’s sign is carpopedal spasm caused by inflating the blood-pressure cuff to a level above systolic pressure for 3 minutes.

Question 18

What are the investigations of low calcium?

Answer 18

Corrected albumin as hypocalcaemia is usually an artefact of low albumin

PTH

Phosphate, vitamin D and magnesium

Question 19

Low calcium with high phosphate indicates?

Answer 19

CKD, hypoparathyroidism, vit D deficiency, hypomagnasaemia

Question 20

Low calcium with low phosphate indicates?

Answer 20

Pancreatitis, bone disease

Question 21

What ECG changes are present low calcium?

Answer 21

Long QT

Question 22

How is low calcium managed?

Answer 22

In the emergency department, magnesium and calcium (in their many different forms) are the only medications necessary to treat hypocalcemic emergencies. The consulting endocrinologist may choose to prescribe any of the various vitamin D supplements depending on laboratory workup findings, and oral calcium supplementation for outpatient therapy.