Chronic Kidney Disease

Question 1

Define chronic kidney disease

Answer 1

• The irreversible and sometimes progressive loss of renal function over a period of months to years
• Renal injury causes renal tissue to be replaced by extracellular matrix in response to tissue damage
• Shrinking of cortex, with medulla normal

Question 2

State causes of chronic kidney disease

Answer 2

• Old age
• Diabetes
• Hypertension
• Obesity
• Immunologic - GN
• CVS disease
• Infection
• Genetic
• Obstruction and reflux nephropathy

Question 3

State the investigations for CKD

Answer 3

• Blood pressure and urine dipstick
• Blood tests - urea, electrolytes, liver function test (albumin), full blood count, bone biochemistry (PTH), CRP, iron
  
  • Identify potential cause of CKD
• Ultrasound - kidney size, obstruction
• Biopsy - check kidney size first as if kidney has shrunk, biopsy would just be scar tissue

Question 4

State the effects of CKD

Answer 4

• Reduced GFR
• Build up of salts and water within the kidney - leads to nocturia
  
  • Decrease in maximum amount of urine that can be secreted
• Acidosis - decreased bicarbonate release from kidney and acid not being secreted as well
• Hyperkalaemia - may have to stop ACE inhibitor/angiotensin receptor blocker
  
  • Avoid other drugs that can increase K - amiloride, spironolactone, trimethoprim
• Uraemia
• Altered drug metabolism - side effects pronounced
• Anaemia - high CRP causes high hepcidin levels reduce iron absorption from gut - iron tablets not as effective
  
  • Just giving erythropoietin will not treat anaemia due to other causes of anaemia from CKD
• Mineral bone disease

Question 5

Describe the effect of mineral bone disease

Answer 5

• CKD causes increased phosphate retention
• Vitamin D levels decrease, causing hypocalcaemia which triggers PTH
• Phosphate retention decreases calcium sensor, increasing PTH
• Secondary parathyroidism
• Renal osteodystrophy
  
  • Cysts and erosion of bone such as spine and fingers
  • Calcification - phosphate and calcium react together around the body
• Management - reduce phosphate intake and giving phosphate binders

Question 6

State the symptoms of CKD

Answer 6

• Tiredness
• Difficulty sleeping and concentrating
• Nausea, vomiting
• Relentless cramps
• Chest pain
• Breathlessness

Question 7

What are management options for CKD

Answer 7

• Stop smoking, lose weight, increase exercise
• Consider stopping proton pump inhibitors
• Control diabetes, hypertension, proteinuria, lipids
• Give ACE inhibitors/angiotensin receptor blockers
• Renal replacement therapy - when eGFR 8-10 ml/min

Question 8

State the 3 types of renal replacement therapy for CKD

Answer 8

• Haemodialysis
• Peritoneal dialysis
• Transplant

Question 9

Describe the advantages of disadvantages for haemodialysis

Answer 9

• 4 hours 3 times a week
• Better for long term prognosis than peritoneal dialysis
• Patients with heart problems don’t tolerate haemodialysis - 400mL of 5L of blood taken out
• Patients need good clotting processes
• Fluid, diet and travel restrictions

Question 10

Describe the advantages and disadvantages of peritoneal dialysis

Answer 10

• Need to maintain every day where bags are changed 4-5 times a day
• Self-sufficient dependence
• Limited dose - does not work as well with obese or very muscular patients
• Risk of peritonitis

Question 11

Decsribe the advantages and disadvantages of kidney transplant

Answer 11

• Restoration of near normal renal function and improved quality of life
• However requires immunosuppression and potential operative morbidity

Question 12

Outline the difference in ICF and ECF when giving saline, dextrose and colloid solution

Answer 12

• When giving saline fluid, it will enter the extracellular compartment
  
  • Majority will remain within the plasma
  • Will not enter the intracellular compartment as isosmotic fluid is added
    
    • ICF and ECF osmolality will not be changed and thus will not enter the ICF
  • Due to the increased volume within plasma, hydrostatic pressure increases which causes some fluid to enter the interstitial fluid
• When giving dextrose solution, glucose will be absorbed into the cells
  
  • Increases osmolality in the ICF and thus draws fluid intracellularly
  • Used to treat fluid loss
• When giving colloid (protein) solution
  
  • Increases oncotic pressure so increases fluid only within the plasma
    
    • Used to treat hypovolaemia but very expensive compared to saline