Chronic Kidney Disease

Question 1

What is chronic kidney disease?

Answer 1

Chronic reduction in kidney function

Question 2

Causes of CKD (6)

Answer 2

Age-related decline

Diabetes

Hypertension

Glomerulonephritis

Polycystic kidney disease

Medications such as NSAIDS, proton pump inhibitors and lithium

Question 3

Risk factors for CKD (5)

Answer 3

Older age

Hypertension

Diabetes

Smoking

Use of medications that affect the kidneys

Question 4

Presentation of CKD (8)

Answer 4

Usually asymptomatic and diagnosed on routine testing

Pruritus (itching)

Loss of appetite

Nausea

Oedema

Muscle cramps

Peripheral neuropathy

Pallor

Hypertension

Question 5

Investigations for CKD

Answer 5

Estimated glomerular filtration rate (eGFR) - Two tests are required 3 months apart

Proteinuria can be checked using a urine albumin:creatinine ratio (ACR)
result of ≥ 3mg/mmol is significant

Haematuria - urine dipstick

Renal ultrasound - investigate patients with accelerated CKD, haematuria, family history of polycystic kidney disease or evidence of obstruction

Question 6

Stages of CKD

Answer 6

G1 = eGFR >90
G2 = eGFR 60-89
G3a = eGFR 45-59
G3b = eGFR 30-44
G4 = eGFR 15-29
G5 = eGFR <15 (known as “end-stage renal failure”)

Question 7

Complications of CKD (5)

Answer 7

Anaemia
Renal bone disease
Cardiovascular disease
Peripheral neuropathy
Dialysis related problems

Question 8

When to refer to a specialist in CKD

Answer 8

eGFR < 30

ACR ≥ 70 mg/mmol

Accelerated progression defined as a decrease in eGFR of 15 or 25% or 15 ml/min in 1 year

Uncontrolled hypertension despite ≥ 4 antihypertensives

Question 9

Aims of management in CKD

Answer 9

Slow the progression of the disease

Reduce the risk of cardiovascular disease

Reduce the risk of complications

Treating complications

Question 10

How is the progression of CKD slowed?

Answer 10

Optimise diabetic control

Optimise hypertensive control

Treat glomerulonephritis

Question 11

How are the risk of complications reduced in CKD?

Answer 11

Exercise, maintain a healthy weight and stop smoking

Special dietary advice about phosphate, sodium, potassium and water intake

Offer atorvastatin 20mg for primary prevention of cardiovascular disease

Question 12

How are complications of CKD treated? (5)

Answer 12

Oral sodium bicarbonate to treat metabolic acidosis

Iron supplementation and erythropoietin to treat anaemia

Vitamin D to treat renal bone disease

Dialysis in end stage renal failure

Renal transplant in end stage renal failure

Question 13

When are ACEi offered to patients with CKD?

Answer 13

Diabetes plus ACR > 3mg/mmol

Hypertension plus ACR > 30mg/mmol

All patients with ACR > 70mg/mmol

Question 14

Why do CKD patients get anaemia?

Answer 14

Healthy kidney cells produce EPO

Damaged kidney cells in CKD cause a drop in erythropoietin

Question 15

How does chronic kidney disease-mineral and bone disorder (CKD-MBD) occur?

Answer 15

High serum phosphate occurs due to reduced phosphate excretion

Low active vitamin D due to reduced kidney function
Active vitamin D is essential in calcium absorption from the intestines and kidneys
Also regulates bone turnover

Secondary hyperparathyroidism - More PTH due to low serum calcium and high serum phosphate
Leads to increased osteoclast activity

Leads to the absorption of calcium from bone
Osteomalacia -
increased turnover of bones without adequate calcium supply
Osteosclerosis occurs when the osteoblasts respond by increasing their activity to match the osteoclasts - new tissue not properly mineralised due to low calcium

Question 16

How is chronic kidney disease-mineral and bone disorder (CKD-MBD) managed?

Answer 16

Active forms of vitamin D (alfacalcidol and calcitriol)

Low phosphate diet

Bisphosphonates can be used to treat osteoporosis