6: Biochemistry of renal disease Flashcards Preview

Renal Week 2 2017/18 > 6: Biochemistry of renal disease > Flashcards

Flashcards in 6: Biochemistry of renal disease Deck (24)
Loading flashcards...
1

Why is inulin a good marker for GFR?

Freely filtered

Not reabsorbed

Not secreted

2

Why isn't inulin always used as a marker for GFR?

Needs to be injected into patient

3

Why isn't urea used as a marker of GFR?

Recycled in kidneys and reabsorbed in GI tract - so GFR isn't constant

4

Which natural substance is used as a marker of GFR?

What's the one caveat?

Creatinine

Small amount secreted into the tubules from capillaries, so can overestimate GFR

5

As GFR decreases, what happens to [creatinine] of the plasma?

Increases

As kidneys can't filter it

6

At high GFRs, [creatinine]serum (is / isn't) useful for estimating kidney function.

isn't sensitive at high GFRs

only sensitive when GFR is low

7

What is clearance?

Volume of plasma cleared of a substance PER MINUTE

8

What two factors affect your creatinine levels?

Muscle mass

Diet

9

Because a biochemist can't gauge a patient's muscle mass and diet off of a sheet of paper, what is used to estimate their creatinine production instead?

Age

Sex

Ethnicity

10

What is the difference between GFR and eGFR?

eGFR modified based on age, sex and ethnicity

As these can affect creatinine production rates

11

Which type of creatinine clearance is more sensitive?

What estimate is better than both of them?

Urinary creatinine > Serum creatinine

eGFR

12

How can the degree of proteinuria be estimated?

24h urine protein collection (gold standard)

Protein/creatinine ratio (more convenient, less accurate)

Urinalysis (even more convenient, least accurate)

 

13

What excretion of protein is an indicator of severe glomerular damage?

> 150 mg/day

14

What is biopsied to diagnose multiple myeloma?

Bone marrow

15

What type of proteinuria is caused by multiple myeloma?

Which type of protein accumulates?

Overflow proteinuria

Bence-Jones protein

16

What type of renal syndrome is seen when the glomeruli are very leaky to proteins?

Nephrotic syndrome

17

What are the signs of nephrotic syndrome?

Proteinuria

Fluid retention and oedema - (pitting) oedema

Hypoalbuminaemia

Hyperlipidaemia

18

What is microalbuminaemia?

Proteinuria in levels undetectable by a urinalysis dipstick

19

Microalbuminaemia is the earliest sign of which disease in diabetics?

Nephropathy

20

Which drugs can slow the progression of renal disease detected early by microalbuminaemia?

ACE inhibitors

ARBs

21

What are some pre-renal causes of oligouria?

What is the mechanism?

Blood loss

Hypovolaemia e.g sepsis

Mechanism: decreased renal perfusion

22

What are some post-renal causes of oligouria?

What is the mechanism of it?

Kidney stones

Malignancy

Blockage of urine flow

23

What are some renal causes of oligouria?

Glomerulonephritis

Nephrotoxic substances

24

If urine osmolality decreases, what is dysfunctional?

Renal tubules

not hyperconcentrating urine anymore