Chronic Kidney Disease

Question 1

What variables are used to calculate the eGFR?

Answer 1

• Serum creatinine
• Age
• Gender
• Ethnicity

Question 2

What is stage 1 CKD classified as?

Answer 2

Greater than 90 ml/min, with some sign of kidney damage on other tests (if all the kidney tests* are normal, there is no CKD)

Question 3

What is stage 2 CKD classified as?

Answer 3

60-90 ml/min with some sign of kidney damage (if kidney tests* are normal, there is no CKD)

Question 4

What is stage 3a CKD classified as?

Answer 4

45-59 ml/min, a moderate reduction in kidney function

Question 5

What is stage 3b CKD classified as?

Answer 5

30-44 ml/min, a moderate reduction in kidney function

Question 6

What is stage 4 CKD classified as?

Answer 6

15-29 ml/min, a severe reduction in kidney function

Question 7

What is stage 5 CKD classified as?

Answer 7

Less than 15 ml/min, established kidney failure - dialysis or a kidney transplant may be needed

Question 8

What are common causes of CKD?

Answer 8

• diabetic nephropathy
• chronic glomerulonephritis
• chronic pyelonephritis
• hypertension
• adult polycystic kidney disease

Question 9

What can patients with CKD develop?

Answer 9

• normocytic anaemia (when eGFR < 35ml/min)
• low vitamin D (1-alpha hydroxylation normally occurs in the kidneys)
• high phosphate
• low calcium: due to lack of vitamin D, high phosphate
• secondary hyperparathyroidism

Question 10

Why does CKD lead to anaemia?

Answer 10

• reduced erythropoietin levels - the most significant factor
• reduced erythropoiesis due to toxic effects of uraemia on bone marrow
• reduced absorption of iron
• anorexia/nausea due to uraemia
• reduced red cell survival (especially in haemodialysis)

Question 11

Why does secondary hyperparathyroidism develop in patients with CKD?

Answer 11

• vit D 1-alpha hydroxylation normally occurs in the kidneys =doesn’t happne
• low calcium due to low vitamin D
• high phosphate develops
• parathyroid hormone activated to increase calcium levels

Question 12

What are the clinical manifestation of secondary hyperparathyroidism in CKD?

Answer 12

• Osteitis fibrosa cystica
• Osteomalacia (low vit D)
• Osteosclerosis
• Osteoporosis

Question 13

What is the mineral bone disease management in CKD?

Answer 13

• reduced dietary intake of phosphate is the first-line management
• phosphate binders
• vitamin D: alfacalcidol, calcitriol
• parathyroidectomy may be needed in some cases

Question 14

What is the management of anaemia in CKD?

Answer 14

• optimisation of iron status (IV iron)

* administration of erythropoiesis-stimulating agents

Question 15

What is used as a marker of CKD, especially for diabetic nephropathy?

Answer 15

• Proteinuria

* Use the albumin:creatinine ratio

Question 16

What is used first line for patients with proteinuria and CKD?

Answer 16

ACEi

*used for coexistent hypertension and CKD

Question 17

What can be used as an antihypertensive in CKD patients when their eGFR falls below 45ml/min?

Answer 17

*Furosemide

added benefit of lowering serum potassium

Question 18

What effect of an ACEi should be expected on eGFR and creatinine?

Answer 18

decrease in eGFR of up to 25% or a rise in creatinine of up to 30% is acceptable on ACEi

Question 19

What drugs should be avoided in renal failure?

Answer 19

• Antibiotics: tetracycline, nitrofuratoin
• NSAIDs
• Lithium
• Metformin