Chronic kidney disease

Question 1

What is CKD?

Answer 1

Long-standing and often deteriorating reduction in renal function due to irreversible loss of nephrons, occuring over years.

Question 2

How does hypertension lead to CKD?

Answer 2

1. Hypertension causes thickening of renal artery walls so narrow lumen
2. Low blood flow to the glomerulus, causing ischaemic injury.
3. This triggers an immune response which leads to glomerular sclerosis and decreased renal function.

Question 3

Give 3 risk factors for CKD.

Answer 3

Acute kidney injury and any causes of AKI (pre-, intra- and post-renal.)
Diabetes (25%) - diabetic nephropathy
Hypertension (20%)
Glomerulonephritis (15%)
Interstitial diseases (10%)
Congenital eg polycystic kidney disease (5%)

Question 4

Give 3 symptoms of CKD

Answer 4

1. Anorexia
2. Nausea/ vomiting/ diarrhoea
3. Restless legs
4. Fatigue and weakness (due to anaemia)
5. Pruritus due to high urea
6. Bone pain
   8 Nocturia, polyuria due to decreased reabsorption.
   (OHCM)

Question 5

Give 3 signs of CKD.

Answer 5

1. polyuria
2. ankle swelling/ oedema.
3. Increased BP.
4. Gradual onset of symptoms
5. Later stages: oligouria, CNS involvement.
   (PTS)

Question 6

What investigations should you do in ?CKD?

Answer 6

Renal USS - small kidneys with increased echogenicity.
Bloods:
Hb - shows normocytic normochromic anaemia.
Glucose - diabetes mellitus
Calcium - decreased
Phosphate - increased
Urine disptick, microbiological cultures, ACR.
Examination - pallow, yellowish tinge, purpura.

Question 7

Define and describe the management of stage 5 CKD.

Answer 7

End-stage renal failure: death is imminent without renal replacement therapy (transplant). GFR <15 if not already on dialysis.
Prepare for dialysis if appropriate.

Question 8

What is uraemia?

Answer 8

High urea in blood. Leads to amennorrhea, impotence.

Question 9

Define and describe the management of stage 1 CKD

Answer 9

Kidney damage present which has been detected by urine test or imaging studies. GFR >90.
Investigate more thoroughly - check for proteinuria and haematuria. (PTS)

Question 10

Define and describe the management of stage 2 CKD

Answer 10

Kidney damage with GFR 60-89.

Renoprotection by controlling blood pressure and having a low-protein diet.

Question 11

Define and describe the management of stage 3 CKD

Answer 11

GFR 30-59. Renoprotection by controlling BP and having a low-protein diet.

Question 12

Define and describe the management of stage 4 CKD

Answer 12

GFR 15-29. Prepare for dialysis if appropriate.

Question 13

Give 3 differences between AKI and CKD.

Answer 13

CKD shows small kidneys while AKI shows normal kidneys
AKI symptoms are more like shock symptoms while CKD is more like serious disease
AKI shows low BP while CDK shows high BP.
AKI shows rapid onset of symptoms while CKD shows slow progression.

Question 14

What are the types of dialysis and which is used more commonly?

Answer 14

Haemodialysis (more common)

Peritoneal dialysis

Question 15

How does haemodialysis work?

Answer 15

In haemodialysis, blood is filtered in a dialysis machine which acts as an artificial kidney, then returned to the body.
Blood is passed over a semi-permeable membrane against dialysis fluid flowing in the opposite direction. Diffusion of solutes occurs down the concentration gradient. A hydrostatic gradient is used to clear excess fluid as required (ultrafiltration).

Question 16

Why should an AV fistula be created prior to dialysis?

Answer 16

An atrioventricular fistula is a surgical anastamosis between an artery and vein, which increases strength and blood flow. This should be created prior to need for dialysis to avoid the infection risk associated with central venous dialysis catheters.

Question 17

How does peritoneal dialysis work?

Answer 17

Blood is filtered within the peritoneal cavity, using the peritoneum as a semi-permeable membrane. A catheter is inserted into the peritoneal cavity and solutes diffuse across. Ultrafiltration is achieved by adding osmotic agents.

Question 18

Give 2 advantages of haemodialysis

Answer 18

4 dialysis-free days a week.

Home dialysis possible for some patients.

Question 19

Give 2 disadvantages of HD

Answer 19

Risk of infection due to access
Hypotension because blood is taken out during HD.
Time-consuming
Have to restrict diet and fluid intake

Question 20

Give 2 advantages of PD

Answer 20

Done at home
More freedom to travel
Fewer restrictions of diet and fluid intake

Question 21

Give 2 disadvantages of PD

Answer 21

Catheter site infection
PD peritonitis
Loss of membrane function over time
Needs to be carried out every day

Question 22

Give 4 drugs that can cause CKD.

Answer 22

DAMN:
Diuretics
ACE inhibitors
Metformin
NSAIDs