Chronic kidney disease

Question 1

Define

Answer 1

pathological abnormality such as haematuria or proteinuria or a reduction in the GFR < 60 ml/min per 1.73 m2 for three months or more

Question 2

What are the stages?

Answer 2

o Stage 1: Normal
• Kidney damage with normal or increased 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
• Kidney damage with eGFR 60-89 ml/min per 1.73 m2 with other evidence of CKD
o Stage 3a: Moderate Impairment
• Kidney damage with moderate decrease in eGFR 45-59 ml/min per 1.73 m2
o Stage 3b: Moderate Impairment
• Kidney damage with moderate decrease in eGFR 30-44 ml/min per 1.73 m2
o Stage 4: Severe Impairment
• Kidney damage with severe decrease in eGFR 15-29 ml/min per 1.73 m2
o Stage 5: Established Renal Failure
• Kidney failure eGFR < 15 ml/min per 1.73 m2 or on dialysis

Question 3

What are the risk factors?

Answer 3

•	In developed countries it is mainly associated with:
o	Age (>50 years)
o	Diabetes mellitus (most common cause – 1/3 of diabetics will develop kidney disease)
o	Hypertension (second most common cause)
o	Obesity 
o	Cardiovascular disease 
o	Black or Hispanic ethnicity
o	Microalbuminuria 
•	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 4

Epidemiology

Answer 4

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

Question 5

What are the presenting symptoms?

Answer 5

• 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 (accumulation of waste products)
o Peripheral oedema
o Muscle cramps
o Pulmonary oedema (leading to dyspnoea and orthopnoea)
• Sexual dysfunction is common

Question 6

What are the signs?

Answer 6

• 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 7

What are the 1st investigations?

Answer 7

• Assessment of Renal Function
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 (>97 in men, >105 in women)
o Isotopic GFR - GOLD STANDARD but expensive
• Biochemistry
o Glucose - check for undiagnosed diabetes and diabetic control
o Potassium - raised
o Also check sodium, bicarbonate, calcium, phosphate
• Serology
o Antibodies
• ANA - SLE
• c-ANCA - granulomatosis with polyangiitis (Wegener’s)
• Anti-GBM - Goodpasture’s syndrome
o Hepatitis serology
o HIV serology
• Urinalysis
o Check for proteinuria/haematuria
o Check microalbumin in urine
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
• Estimation of GFR (<60)

Question 8

What are some investigations to consider?

Answer 8

renal biopsy,

serology