Chronic Kidney Disease

Question 1

What is the definition of CKD?

Answer 1

• Kidney damage or GFR<60ml/min per 1.73m² for 3 months or more

Question 2

How is CKD classified?

Answer 2

Question 3

What are the intractable symptoms of CKD5?

Answer 3

• Pruritis (itch)
• Loss of appetite
• Nausea – morning and meat
• Loss of stamina – ‘tiredness’
• Oedema – peripheral and pulmonary
• Muscle cramps
• Peripheral neuropathy
• Pallor
• HTN
• Thirst
• Metallic taste
• Coldness
• Restless legs
• Menstrual irregularity
• Chest pain – beware pericarditis
• Pericardial rub
• Rash/excoriation
• Tachypnoea
• Cachexia

Question 4

How is CKD treated?

Answer 4

• Slow progression
  
  • BP and DM control (more stringent in those with proteinuria - 130/80)
  • In patients with proteinuria, inhibition of the RAAS system confers greater benefit than BP alone (ACE-I, ARB)
  • Treat GN
• Reduce risk of complications
  
  • Exercise, maintain healthy weight, stop smoking
  • Special diet - phosphate, sodium, potassium and water intake
  • Atorvastatin for reduction in CV risk
• Treat complications
  
  • 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 5

How are the consequences of CKD treated?

Answer 5

• Adjust drug doses (e.g. insulin)
• Anaemia (EPO, iron, B12, folate)
• Acidosis (sodium bicarbonate)
• Hyperkalaemia (correct acidosis, restrict diet, stop relevant drugs)
• Abnormal calcium and phosphate metabolism (diagram below)
• Secondary hyperparathyroidism (prevent with phosphate binders, treat with cinacalcet or parathyroidectomy)

Question 6

What are the problems with serum creatinine?

Answer 6

• Exponential relationship means there is slow recognition of loss of the first 70% of renal function and then a sudden rise
• Muscle mass also leads to overestimation of function in women, the elderly and low muscle mass groups (i.e. amputees)

Question 7

What are the problems with eGFR?

Answer 7

• Only validated in whites and African-Americans
• Mean age 50yrs (not validated in elderly)
• Values above 60ml/min not distinguishable
• Not valid in AKI
• Drug dosing (doesn’t take weight into account)
• Pregnancy

Question 8

What are the normal ACR and PCR?

Answer 8

• ACR <2.5
• PCR <20
• Albuminuria is ACR >30
• ACR is about 2/3 of the equivalent PCR result
• Nephrotic range proteinuria is PCR >300 (3g/24hrs)

Question 9

How is CKD investigated?

Answer 9

• eGFR
• Proteinuria (urine albumin:creatinine ratio/ACR)
• Haematuria (urine dipstick)
• Renal ultrasound with accelerated CKD (i.e. APKD, obstruction)