Electrolyte Imbalance

Question 1

Endocrine causes of hypokalemia?

Answer 1

Conns,
Cushing’s,
Liddles,
Bartters syndrome

Question 2

What is bartters syndrome?

Answer 2

Inherited cause of disfunction of NKCC2 cotransporter in loop of henle. (Same as action of furosemide)

Features - normotension, polyuria, poly dipsia, childhood (failure to thrive), weakness,

Question 3

What special tests can be used to elicit signs of hypocalemia on clinical examination?

Answer 3

Trousseau sign - after blood pressure, hand spasm with finger adduction and wrist flextion.

Chvosteks sign - tap over parotid (c7), facial muscle twitch,

Question 4

What’s the Acid-base balance show in Cushing’s and why?

Answer 4

Hypokalemia metabolic alkalosis

High cortisol levels - interact with mineralocorticoid receptors (like in cons) cause low K, low H and high Na.

Question 5

Deficiency of which mineral can cause hypocalemia and low PTH secretion?

Answer 5

Magnesium

Question 6

What’s the treatment for acute hypercalcaemia?

Answer 6

• rehydration with normal saline

- bisphosphonates can be used (IV bisphosphonate if calcium >3)

Question 7

When to treat hypocalcemia?

Answer 7

IV calcium gluconate if frank tetany or level <1.9

Oral calcium supplements if symptoms persist post surgery (parathyriodectomy) and consider vit d.

If just had surgery - might take time for calcium to normalise - can observe