Lecture 3 - Chronic Kidney Disease

Question 1

CKD Definition

Answer 1

• The presence of kidney damage or decreased kidney function for three or more months, irrespective of the cause.
• GFR less than 60

Question 2

Stage 1 CKD

Answer 2

• Kidney damage with normal or increased GFR
• ≥90 (mL/min/1.73m²)

Question 3

Stage 2 CKD

Answer 3

• Kidney damage with mildly decreased GFR
• 60-89

Question 4

Stage 3 CKD (a&b)

Answer 4

• Moderately reduced GFR
• a:
• 45-59
• b:
• 30-44

Question 5

Stage 4 CKD

Answer 5

• Severely decreased GFR
• 15-29

Question 6

Stage 5 CKD

Answer 6

• Kidney failure
• <15 (or dialysis)

Question 7

Signs

Answer 7

• Raised BP
• High urea, uremic frost, sweating urea
• Hyperkalaemia (cardiac issues)
• Hypocalcaemia
• Uremia
• Oedema
  *

Question 8

Symptoms

Answer 8

• Fatigue
• Swollen ankles, feet or hands
• Shortness of breath
• Feeling sick
• Blood in your urine
• Kidney pain in back

Question 9

Cardiac ouput to kidney

Answer 9

25%

Question 10

Markers of Kidney Dysfunction

Answer 10

• GFR
• Urine dipstix: blood, protein
• Kidney scan
• Kidney transplant means they already have CKD

Question 11

Creatinine

Answer 11

• Creatinine clearance equivalent of GFR
• Easily measured byproduct of muscle metabolism that is excreted unchanged by the kidneys.
• Problem is CrCl rate will overestimate the GFR because hypersecretion of creatinine by the proximal tubules will account for a larger fraction of the total creatinine cleared

Question 12

GFR

Answer 12

• Glomerular filtration rate (GFR) is the volume of fluid filtered from the glomerular capillaries into the Bowman’s capsule per unit time
• Measured:
• Inulin injection
• Chromium 51

Question 13

Normal GFR

Answer 13

120ml/min

Question 14

eGFR

Answer 14

• Creatinine
• Cockroft-Gault formula
• Modification of Diet in Renal Disease (MDRD)
• Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI)
• Cystatin C

Question 15

Problems with eGFR

Answer 15

• Extremes of age / body size / race affect it
• Body builder seemingly low rate, elderly seemingly high
• Based on caucasians

Question 16

Why important to know about CKD?

Answer 16

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• Kidney failure independent risk factor for cardiovascular disease
• Therefore important to pick up early and prevent progression

Question 17

UK CKD Burden

Answer 17

• 35,000 patients on dialysis or transplant per year
• £2 billion spent on it per year
• 10% of population have CKD

Question 18

Causes of CKD

Answer 18

• Diabetes (30%)
• Vascular (atherosclerosis, hypertension, smoking)
• Glomerulonephritis
• Tubulointerstitial nephritis
• Urological - obstruction stones etc
• Congenital, polycystic kidneys
• Autoimmune

Question 19

Investigations of CKD

Answer 19

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• Detailed history - co-morbidities
• Family history - members on dialysis
• Uraemic symptoms
• BP, Oedema, JVP
• eGFR

Question 20

Monitoring CKD

Answer 20

• G1 & G2 = Annually
• G3 a & b = 6-monthly
• G4 = 3-6 monthly
• G5 = 3 monthly

Question 21

General management

Answer 21

• Smoking cessation
• Salt intake
• Weight loss
• Regular aerobic exercise
• Limit alcohol intake
• Aspirin
• Lipid-lowering therapy
• Hypertension + blood sugar control
• Statins

Question 22

Therapeutics

Answer 22

• ACE Inhibitors
• ARB (angiotensin II receptor blockers)
• Vitamin D supplements (G4 & 5 decrease vitamin D = hyperparathyroidism)
• Erythropoietic stimulating agents (ESAs) - CKD lowers Haemoglobin = anaemia

Question 23

Management of End Stage Kidney Disease

Answer 23

• Renal replacement therapies:
• Transplantation
• Dialysis
• Conservative management (too advanced, elderly etc so just treat symptoms and allow end stage to occur)