Biochemical measurements in renal disease Flashcards Preview

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Flashcards in Biochemical measurements in renal disease Deck (25)
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1
Q

What tests are used to measure glomerular function (GFR)?

A

Urea
Creatinine
eGFR

2
Q

What is urea?

A

End breakdown product of protein from the colon and liver

3
Q

What is creatinine?

A

Product of protein intake - it will change depending on the muscle mass of a person and the protein intake of a person

4
Q

What is a normal GFR?

A

Around 120 ml/min - anything above is normal

5
Q

What is the issue with creatinine as a measurement of GFR?

A

Between 60-120, the creatinine won’t really change

6
Q

What is the issue with urea as a measurement of GFR?

A

Dependent on the protein content in the diet
Reabsorbed from the renal tubule
Around 25% is eliminated in the liver

7
Q

What are confounders to serum creatinine?

A
Age
Sex
Ethnicity
Muscle mass
Diet
8
Q

What is eGFR?

A

Adjusts for proxies of diet, muscle mass, age, sex and ethnicity

9
Q

How is urinary creatinine clearance calculated?

A

creatinine in the urine x urine volume
DIVIDED BY
creatinine in the serum x duration of collection

10
Q

What is the best way to determine a precise GFR?

A

Cr-EDTA clearance - not used that often

11
Q

What GFR indicated kidney damage?

A

GFR 60-90

12
Q

What GFR indicated moderate kidney damage?

A

30-59

13
Q

What GFR indicated severe kidney damage?

A

15-29

14
Q

What GFR indicates kidney failure?

A

Less than 15

15
Q

How is proteinuria measured?

A

24-hour collection

Protein/creatinine ratio of a spot sample is also helpful

16
Q

What level of proteinuria indicated significant glomerular damage?

A

More than 150mg/day

17
Q

What are the different types of proteinuria?

A
Normal
Overflow (multiple myeloma)
Glomerular (albuminuria) 
Tubular
Secreted
18
Q

What is nephrotic syndrome?

A

Loss of albumin in the capillaries creating a low oncotic pressure, therefore the fluid will leak out of the capillaries into the surrounding tissues (pitting oedema, periorbital swelling)

19
Q

What is microalbuminuria?

A

Excretion of albumin in abnormal quantities by still below the limit of protein detection by dipstick

20
Q

What is the treatment for microalbuminuria?

A

ACEI

21
Q

What can cause an intrinsic kidney tissue damage?

A

Glomerulonephritis

Pyelonephritis

22
Q

What can cause reduced renal perfusion?

A

Hypovolaemia

23
Q

What can cause a post-renal damage?

A

Stones or malignancy

24
Q

What will pre-renal failure show biochemically?

A

Tubules working
Urine sodium <20 mmol/L
Urine/serum urea >10:1
Urine/serum osmolality >1.5:1

25
Q

What will intrinsic renal damage show biochemically?

A

Tubules NOT working
Urine sodium >40mmol/L
Urine/serum urea <3:1
Urine/serum osmolality <1/1:1