Chronic kidney disease

Question 1

Define CKD

Answer 1

a reduction in kidney function, characterised by a reduction in GFR, which is not reversible and may be progressive

Question 2

What is a normal adult 2-kidney GFR?

Answer 2

120ml/min/1.73m^2

Question 3

How is CKD staged?

Answer 3

CGA

Cause
Glomerular stage
Albuminuria stage

Question 4

Markers of kidney disease

Answer 4

GFR<60
albuminuria/haematuria
electrolyte abnormalities due to tubular disorders
structural/histological abnormalities
kidney transplantation

Question 5

How long does kidney damage have to last to be CKD?

Answer 5

> 3 months (more than one blood test/urine sample)

or expected to last >3 months (transplant, polycystic kidneys etc)

Question 6

How are pre-renal, renal and post-renal AKIs treated?

Answer 6

pre-renal = good perfusing pressure (fluids) and oxygen delivery

renal = remove nephrotoxins, treat inflammation

post-renal = ensure free urinary flow

Question 7

CKD causes

Answer 7

diabetes
hypertension
renovascular disease
reflux disease
obstructive uropathy
autosomal dominant polycystic kidney disease
glomerulonephritis
unknown

Question 8

CKD management (1,2,3a)

Answer 8

identify cause - US, biopsy, urine dip
treat cardiovascular risk factors - BP, DM, smoking, weight, activity, salt, proteinuria
monitor progression

Question 9

What is the blood pressure target in CKD?

Answer 9

systolic below 140
diastolic below 90

if diabetic or ACR>70:
- systolic below 130
- diastolic below 80

Question 10

Why are ACE-is/ARBs used in CKD?

Answer 10

block angiotensin 2
dilate efferent arteriole
reduce GFR but increase tubular blood flow

Question 11

How much is creatinine allowed to rise on ACE-is/ARBs?

Answer 11

<30% is acceptable

Question 12

What is normal rate of GFR decline after 40?

Answer 12

1ml/min/year after 40

Question 13

CKD management (3b,4)

Answer 13

ongoing risk factor management

non-glomerular functions start to be relevant (iron-erythropoietin balance, calcium-phosphate balance)

tubular function can start to decline (low potassium diet, oral bicarbonate)

Question 14

Complications of CKD

Answer 14

anaemia of CKD
mineral bone disorder of CKD
salt and water, acid-base disorders
uraemia
disease-specific complications

Question 15

When should EPO replacement be considered in CKD?

Answer 15

if circulating iron stores are well replaced (ferritin 200-500, TFsat >20%) and Hb still low

Question 16

EPO side effect

Answer 16

hypertension

Question 17

What happens to phosphate in CKD? What effects does this have?

Answer 17

hyperphosphataemia
tubular function declines, phosphate builds up
high phosphate lowers calcium
parathyroid responds to low calcium –> 2ndry hyperparathyroidism
eventually 3rdry parathyroidism

Question 18

Uraemia symptoms

Answer 18

GI disturbances
uraemic encephalopathy
pericarditis
leg cramps
restless legs
mood and sleep disturbance
gout
fatigue, lethargy

Question 19

CKD management (5)

Answer 19

prepare for RRT
close monitoring of progression
may need fluid ration - can start to get problems with salt and water

Question 20

What are the options for renal replacement therapy?

Answer 20

haemodialysis
peritoneal dialysis
transplantation (cadaveric waiting list/planned living donor)

Question 21

How can you help to preserve veins in haemodialysis/end-stage renal failure patients?

Answer 21

no bloods/cannulae from elbow to wrist
avoid subclavian lines if possible
never use HD line or fistula for bloods/access

Question 22

Dialysis drawbacks

Answer 22

only replace glomerulotubular functions of kidney and incompletely at that
returns you to GFR of ~15
poor at clearing phosphate
not a great quality of life

Question 23

When to start dialysis in CKD?

Answer 23

creatinine stops being useful measure in CKD 5

guided by sx or intractable biochemistry:
- unmanageable salt-water/potassium
- nausea, vomiting, weight loss, protein malnutrition
- uraemic encephalopathy

Question 24

When should dialysis not be started in CKD?

Answer 24

conservative management is appropriate for many frail elderly/unwell patients

symptom management:
- low protein diet
- fluid rationing
- antihistamines for pruritis
- antiemetics for nausea

Question 25

Stage 1 CKD criteria

Answer 25

eGFR>90 but other tests have detected signs of kidney damage

Question 26

Stage 2 CKD criteria

Answer 26

eGFR 60-89
and other signs of kidney damage

Question 27

Stage 3a CKD criteria

Answer 27

eGFR 45-59

Question 28

Stage 3b CKD criteria

Answer 28

eGFR 30-44

Question 29

Stage 4 CKD criteria

Answer 29

eGFR 15-29

Question 30

Stage 5 CKD criteria

Answer 30

eGFR <15