Chronic kidney disease

Question 1

What is chronic kidney disease?

Answer 1

Reduced GFR and/or evidence of kidney damage over a long period of time

Question 2

How is GFR assessed?

Answer 2

24 hour urine collection (creatinine clearance)

eGFR (serum creatinine, age, sex & race)

Question 3

Creatinine is a product of the breakdown of what?

Answer 3

Muscle

Question 4

What are the drawbacks of eGFR?

Answer 4

Not sensitive over 60ml/min
Over estimates if muscle mass low
Under estimates if muscle mass high
Only valid is serum creatinine is stable (not acute illness)

Question 5

When might we want to directly measure GFR with nuclear medicine?

Answer 5

Screening for kidney donation

Very high or low muscle mass

Question 6

Describe the stages of CKD

Answer 6

Stage 1 - GFR >90 with evidence of kidney damage
Stage 2 - GFR 60-90 with evidence of kidney damage
Stage 3 - GFR 30-60 (A- 45-60 B- 30-44)
Stage 4 - GFR 15-30
Stage 5 - GFR

Question 7

What do we mean by “evidence of kidney damage”?

Answer 7

Proteinuria
Haematuria
Abnormal imaging

Question 8

How common in CKD?

Answer 8

Mild CKD is fairly common especially in the elderly

Question 9

Why does CKD staging matter if most people don’t progress to severe disease?

Answer 9

Must identify those at risk of progression through the stages
Increased CVS risk is important in patient health

Question 10

Who is likely to progress to severe CKD? Why?

Answer 10

Those with proteinuria (more protein - faster progression)
Younger patients (longer to progress)

Question 11

What are the common causes of CKD?

Answer 11

Diabetes mellitus
Hypertension
Vascular disease (renal artery stenosis, large vessel disease, etc)
Chronic glomerulonephritis
Reflux nephropathy 
Polycystic kidneys

Question 12

How does CKD present?

Answer 12

Asymptomatic until GFR

Question 13

How is CKD managed?

Answer 13

Slow progression
Manage CVS risk
Treat complications
Prepare for replacement therapy

Question 14

How can progression of renal disease be slowed?

Answer 14

Reducing proteinuria - control BP with ACE/ARB +/- spironolactone
Glucose control
Smoking cessation

Question 15

How do ACE/ARBs characteristically affect the kidney when they are started? What is the risk of this? How is this monitored?

Answer 15

Initially reduce GFR –> risk of hyperkalaemia

Blood test a week or so post starting drugs

Question 16

How might you reduce CVS risk in patients with CKD?

Answer 16

Smoking cessation
BP control
Statins (stage 4)

Question 17

What are the complications of CKD?

Answer 17

Anaemia

Bone disease

Question 18

Why is anaemia a complication of CKD?

Answer 18

Erythropoietin (stimulates RBC formation) production declines in CKD

Question 19

If a CKD patient has anaemia what must be measured?

Answer 19

Iron
Vitamin B12
Folate

Can all be other causes of anaemia

Question 20

How is anaemia of CKD treated?

Answer 20

IV iron

If iron doesn’t work weekly/fortnightly SC injection of erythropoietin

Question 21

What is the target haemoglobin in CKD anaemia?

Answer 21

105-125 g/dl

Question 22

If giving erythropoietin for CKD what else must be given?

Answer 22

Iron (as stores depleted)

Question 23

How is vitamin D metabolised in the kidney?

Answer 23

Hydroxylated

Question 24

What happens to vitamin D metabolism in CKD?

Answer 24

Reduced calcium absorption –> secondary hyperparathyroidism

Serum phosphate raised (advanced disease) –> increases PTH secretion

Question 25

Hyperplasia of all parathyroid glands occurs in CKD. T/F

Answer 25

True

Question 26

Explain tertiary hyperparathyroidism and its main complication

Answer 26

Autonomous production of PTH even when serum calcium normal --> hypercalcaemia

Question 27

What is the sequelae of CKD bone disease?

Answer 27

Severe bone disease (pain & imaging changes) uncommon | High phosphate and calcium --> calcification of vessels and heart valves

Question 28

How is bone disease in relation to CKD managed?

Answer 28

``` Alfacalcidol (hydroxylated vit D) Adjustment of phosphate intake in diet Phosphate binders (bind to phosphate in gut to reduce absorption) ```

Question 29

Name three phosphate binders

Answer 29

Calcium carbonate Calcium acetate Sevelamer

Question 30

Name three types of renal replacement therapy

Answer 30

Haemodialysis Peritoneal dialysis Kidney transplant

Question 31

What is the best form of dialysis access? How long does it take to mature?

Answer 31

Arteriovenous fistula | 6 weeks

Question 32

Why is an operation needed in peritoneal dialysis? How long does it take to mature?

Answer 32

Insertion of cannula | 1-2 weeks

Question 33

How long must people be able to live to be considered for a transplant?

Answer 33

At least 5 years

Question 34

When is conservative management indicated over dialysis?

Answer 34

Older patients with multiple co-morbidities | Symptom control still given