8 - renal biochemistry

Question 1

Give some roles of the kidney

Answer 1

Regulates extra cellular fluid volume and electrode balance
Excretion of waste products
Selective reabsorption
Secondary endocrine function (production of erythropoietin and renin)

Question 2

What does erythropoietin do?

Answer 2

stimulates RBC production

Question 3

What does renin do?

Answer 3

It is involved in the renin angiotensin aldersterone system which balances sodium, potassium and water levels in the blood stream.

Question 4

How does hypovaleamia impact electrolyte levels?

Answer 4

It causes low sodium and potassium (hyponatremia and hypokaleamia)

Question 5

What is the role of aldosterone?

Answer 5

It causes reabsorption of sodium (and therefore water) in the nephron

Question 6

What does ADH (vasopressin) do?

Answer 6

Increases reabsorption of water in the collecting ducts if the kidney

Question 7

What are some causes of hypernatraemia?

Answer 7

Water depletion, excessive sodium intake and renal failure

Question 8

How would you treat hypernatraemia?

Answer 8

Oral water or IV with 5% dextrose

Question 9

What are clinical signs of hypernatraemia?

Answer 9

Decreased urine output, dry mucus membranes and low blood pressure (or high of salt gain

Question 10

What is a cause of oedematous hyponatraemia?

Answer 10

Heart failure

Question 11

How would you treat oedematous hyponatraemia?

Answer 11

Diuretic, restrict fluid and treat the underlying condition

Question 12

What is a cause of non-oedematous hyponatraemia?

Answer 12

An increase in release of ADH secretion (Syndrome of inappropriate antidiuresis) which can be caused by an infection or malignancy

Question 13

What are some causes of hyponatraemia via sodium loss?

Answer 13

Vomiting and diarrhoea, lack of sodium intake and lack of aldersterone

Question 14

What are some clinical signs of hyponatraemia via sodium loss?

Answer 14

Tachycardia and hypotension

Question 15

How would you treat hyponatraemia via sodium loss?

Answer 15

Oral correction of sodium loss or aldersterone therapy if it is caused by lack of aldersterone

Question 16

What can hyperkalemia cause?

Answer 16

cardiac arrest

Question 17

What can hypokalemia lead to?

Answer 17

Weak, cardiac arrhythmias

Question 18

What are some causes of hyperkalaemia?

Answer 18

Renal failure, adrenal failure and release of potassium from damaged cells

Question 19

How would you treat hyperkalaemia?

Answer 19

Calcium glauconate to protect the heart and insulin and glucose and dialysis to reduce potassium levels

Question 20

What are some causes of hypokalaemia?

Answer 20

Vomiting, diarrhoea and diuretics

Question 21

How do you treat hypokalaemia?

Answer 21

Oral or IV potassium (slowly with ECG monitoring)

Question 22

What are some biochemical findings of acute renal failure?

Answer 22

Concentrated urine, increased serum urea and creatinine and hyperkalaemia

Question 23

What are some causes of acute renal failure?

Answer 23

Pre-renal - damage to kidney’s blood supply
Renal - damage time kidney tissue
Post-renal - obstruction blocks urinary drainage

Question 24

How do you treat acute kidney failure?

Answer 24

Treat the underlying causes and use dialysis if necessary

Question 25

What are some biochemical findings of chronic renal failure?

Answer 25

Hyperkalaemia and high serum urea and creatinine

Question 26

What is the management of chronic renal failure?

Answer 26

Sodium restriction
Dietary protein restriction
Diuretics
Oral exchange resin (to reduce potassium)
Dialysis and transplant in the long term