Clinical Biochemistry 2

Question 1

What is GFR?

Answer 1

Glomerulus Filtrate Rate - used for overall health and drug excretion

Question 2

What is used as a proxy marker for GFR and why?

Answer 2

Creatinine as it is completely filtered by the kidneys and reabsorbed

Question 3

State the Cockcroft-Gault equation.

Answer 3

CrCl (mL/min) = (140-age) x weight x (1.23 male/1.04 female)/SrCr (μmol/L)

Question 4

What is the genera, rule when calculating creatinine clearance?

Answer 4

• 50 – 20 mL/min - mild impairment
• 20- 10 mL/min - moderate
• < 10mL/min - severe

Question 5

When would there be inaccuracy with GFR?

Answer 5

• Significant muscle wastage is present.
• Patients with low muscle mass.
• Cachexic patients.
• Rapidly changing serum creatinine levels.