Kidney Replacement Therapy

Question 1

List the functions of the kidney

Answer 1

• water regulation
• excretion of waste (urea/creatinine)
• regulation of electrolytes and acid-base balance
• mineral and glucose metabolism
• production of renin and EPO

Question 2

What are the indications for KRT?

Answer 2

• medically resistant/acute hyperkalaemia
• medically resistant/acute pulmonary oedema
• medically resistant/acute acidosis
• uraemia pericarditis
• uraemia encephalopathy
• specific drug overdoses (even in absence of kidney failure)

Question 3

What are the clinical features of uraemia?

Answer 3

• anorexia and vomiting
• itch
• restless legs
• weight loss
• metallic taste

Question 4

What are the main modalities for KRT?

Answer 4

• haemodialysis (hospital/home)
• peritoneal dialysis (CAPD/APD - home based)
• renal transplant (cadaveric/living)

Question 5

What considerations must be made when deciding what KRT modality to give?

Answer 5

• lifestyle
• frailty
• vascular access
• time (travel to and from hospital)
• carers
• physical (eg. multi-morbidity, malignancy, dementia, psychiatric disease)

Question 6

Describe the process of haemodialysis

Answer 6

• blood removed with blood pump through arterial circuit to dialysis filter
• removal of solutes occurs through diffusion into dialysis solution, and filtration occurs through hydrostatic pressure depending on the balance of solutes in the dialysis solution made up by the clinician
• filtered blood flows out other side through filter through the venous circuit to the air detector back to the patient

Question 7

What are the possible complications of haemodialysis?

Answer 7

Solute/fluid movement:
- crash (acute hypotension)
- cramps
- fatigue
- hypokalaemia
- dialysis disequilibrium

Complication of invasive treatment:
- blood loss
- access problems
- air embolism

Question 8

Describe the process of peritoneal dialysis

Answer 8

• access to peritoneal space through peritoneal catheter
• dialysis solution flows from a bag into the peritoneal space, when empty patient can disconnect
• throughout time the fluid absorbs waste and extra fluid from peritoneal capillaries (osmotic gradient)
• after a few hours, waste is drained from the peritoneal cavity into the empty bag which can be thrown away
  CAPD (waking up and draining a bag and repeating process throughout the day)
  APD (done continuously automated throughout the night)

Question 9

Describe the possible complications of peritoneal dialysis

Answer 9

Solute/fluid movement:
- glucose overload
- hypoalbuminaemia

Complication of invasive treatment:
- infection (peritonitis)
- mechanical (hernia, diaphragmatic leak, dislodged catheter)
- peritoneal membrane failure
- encapsulating peritoneal sclerosis

Question 10

What patients are unsuitable for peritoneal dialysis?

Answer 10

• severely obese
• intra-abdominal adhesions
• frail
• home not suitable

Question 11

What problems associated with CKD are not solved by dialysis and how can they be addressed?

Answer 11

• anaemia (erythropoiesis stimulating agents and iron replacement)
• renal bone disease (phosphate binders and vitamin D)
• neuropathy
• endocrine disturbances (parathyroid, glucose)

Question 12

What are the advantages of kidney transplant?

Answer 12

• no dialysis
• better level of renal function
• can live more independently
• better life expectancy
• improved fertility
• cost

Question 13

What are the disadvantages of kidney transplant?

Answer 13

• immunosuppressive medication taken during duration of transplant
• increased CV risk
• increased infection
• post-transplant diabetes
• skin malignancies