Urinary System 8 - What happens when the kidneys stop working?

Question 1

What happens when the kidneys stop working?

Answer 1

• Loss of excretory function
• Loss of homeostatic function
• Loss of endocrine function (loss of erythropoitin production and vitamin D)
• Abnormality of glucose homeostasis (decreased gluconeogenesis)

Question 2

List the symptoms of kindey disease

Answer 2

• Extreme lethargy, weakness, anorexia
• Hypotension (can have hypertension)
• Elevated urea and creatinine
• Metabolic acidosis
• Anaemia
• These symptoms of tubulointerstitial disorders
• Most common to retain sodium and have hypertension
• Increased cardiovascular risk

Question 3

What causes symptoms of lethargy and anaemia?

Answer 3

• Accumulation of nirogenous waste
• Acidosis, hyponatraemia, volume depletion
• Anaemia

Question 4

What are the complications of acidosis?

Answer 4

• Increased H+ entry into cells in exchange for K+
• Cause hyperkalaemia
• Hyperkalaemia causes arrhythmias, shown by initial loss of p waves, tented t waves, bradycardia and arrest

Question 5

List the increased cardiovascular risks associated with kidney failure

Answer 5

• Hypertension
• Secondary cardiac effects
• Endothelial effects
• Lipid abnormalities

Question 6

How can acute and chronic loss of kindey function be identified?

Answer 6

• Acute has an unchanged renal size, and no history of high creatinine
• Chronic often has reduced kidney size, previously abnormal creatinine and chronic urearnic symptoms

Question 7

List the methods of assessing GFR

Answer 7

• Urea
• Creatinine
• Creatinine clearance
• Inulin clearance
• Radionuclide studies

Question 8

How effective is urea in assessing GFR?

Answer 8

• Poor indicator

- Confounded by diet, GI bleeding, drugs, liver function

Question 9

How effective is creatinine in assessing GFR?

Answer 9

• Affected by muscle mass, age, race and sex

- Look at the patient when interpreting the results

Question 10

How effective is creatinine clearance in assessing GFR?

Answer 10

• Difficult for elderly patients to collect a sample

- Overestimates GFR

Question 11

How effective is inulin clearance at assessing GFR?

Answer 11

• Laborius, only used for research purposes

Question 12

How effective are radionuclide studies at assessing GFR?

Answer 12

• EDTA clearance

- Reliable but expensive

Question 13

List the long term changes required in renal failure

Answer 13

• Dialysis
• Low potassium diet and fluid restriction
• Vitamin D suppliments and erythropoietin injections