Biochemistry iRAT/tRAT questions Flashcards
What is the key mechanism by which the kidneys regulate blood volume?
Excretion of sodium
How can central and nephrogenic diabetes insipidus be distinguished?
administration of DDAVP, the synthetic analogue of ADH
How can primary and secondary adrenal insufficiency be distinguished?
Measurement of ACTH levels (high in primary, low in secondary)
Why are changes such as osteitis fibrosa cystica rarely seen any more?
Hypercalcaemia as a result of primary hyperparathyroidism is usually picked up much earlier now, before these changes manifest
Why are patients with hypercalcaemia always rehydrated early in management?
Hypercalcaemia interferes with proximal tubular reabsoprtion of sodium and water; hence patients are usually dehydrated
What are the most likely causes of hyperkalaemia?
Haemolysis
Renal failure
Anti-hypertensive drugs e.g. ACE inhibitors, spironolactone
