Chronic Kidney Disease

Question 1

Definition

Answer 1

• Progressive loss of kidney function over a period of months or years
• The definition is based on the presence of kidney damage or decreased kidney function (i.e. eGFR < 60 ml/min per 1.73 m2) for three months or more

Question 2

Classification

Answer 2

o Stage 1: Normal
• eGFR > 90 ml/min per 1.73 m2 with other evidence of CKD (microalbuminuria, proteinuria, haematuria, structural abnormalities,
biopsy showing glomerulonephritis)

o Stage 2: Mild Impairment
• eGFR 60-89 ml/min per 1.73 m2 with other evidence of CKD

o Stage 3a: Moderate Impairment
• eGFR 45-59 ml/min per 1.73 m2

o Stage 3b: Moderate Impairment
• eGFR 30-44 ml/min per 1.73 m2

o Stage 4: Severe Impairment
• eGFR 15-29 ml/min per 1.73 m2

o Stage 5: Established Renal Failure
• eGFR < 15 ml/min per 1.73 m2 or on dialysis

Question 3

Associations

Answer 3

• In developed countries it is mainly associated with:
o Age
o Diabetes mellitus
o Hypertension
o Obesity
o Cardiovascular disease

Question 4

Risk factors

Answer 4

Other risk factors:
o Arteriopathic renal disease
o Nephropathies
o Family history
o Neoplasia
o Myeloma
o Systemic disease (e.g. SLE)
o Smoking 
o Chronic use of NSAIDs

Question 5

Epidemiology

Answer 5

• COMMON
• Risk increases with age
• Often associated with other diseases (e.g. cardiovascular disease)

Question 6

Presenting symptoms

Answer 6

• Often ASYMPTOMATIC
• May be an incidental finding of a routine blood or urine test

• Symptoms of Severe CKD:
o Anorexia
o Nausea and vomiting
o Fatigue
o Pruritus
o Peripheral oedema
o Muscle cramps
o Pulmonary oedema

• Sexual dysfunction is common

Question 7

Signs on physical examination

Answer 7

• Physical examination rarely reveals many clues
• May show signs of underlying disease (e.g. SLE)
• May show complications of CKD (e.g. anaemia)

• Signs of CKD:
o Skin pigmentation
o Excoriation marks
o Pallor
o Hypertension
o Peripheral oedema
o Peripheral vascular disease

Question 8

Investigations (assessing renal function)

Answer 8

o Urea - not ideal because it varies massively depending on hydration status and
diet

o Creatinine - useful but has limitations. Renal function can drop considerably with minimal change in serum creatinine

o Isotopic GFR - GOLD STANDARD but expensive

Question 9

Investigations (biochemistry)

Answer 9

o Glucose - check for undiagnosed diabetes and diabetic control
o Potassium - raised
o Also check sodium, bicarbonate, calcium, phosphate

Question 10

Investigations (serology)

Answer 10

o Antibodies
• ANA - SLE
• c-ANCA - granulomatosis with polyangiitis (Wegener’s)
• Anti-GBM - Goodpasture’s syndrome

o Hepatitis serology

o HIV serology

Question 11

Investigations (other)

Answer 11

• Urinalysis
o Check for proteinuria/haematuria
o 24 hr urine collection
o Serum or urine protein electrophoresis - check for multiple myeloma

• Imaging
o Ultrasound - check for structural abnormalities
o CT/MRI
o X-Ray KUB - check for stones

• Renal Biopsy