Basics of Dialysis & Transplantation

Question 1

What are the absolute indications for acute dialysis? (remember AEIOU)

Answer 1

• A – Acidosis (severe and not responding to treatment)
• E – Electrolyte abnormalities (severe and unresponsive hyperkalaemia)
• I – Intoxication (overdose of certain medications)
• O – Oedema (severe and unresponsive pulmonary oedema)
• U – Uraemia symptoms such as seizures or reduced consciousness

Question 2

How does haemodialysis work?

Answer 2

• Movement of solutes down a concentratin gradient so blood solute concentration falls
• Movement of fluid by convection down a pressure gradient so blood volume falls
• Other end has a lowe potassium and lower urea concentration
• Also convection removes around 2/5l of fluid)

Question 3

How does peritoneal dialysis work?

Answer 3

• Peritoneal membrane is used for diffusion and glucose is used as the osmotic agent
• Catheter inserted so dialysate fluid can be injected into abdomen and the peritoneum acts as the semipermeable membrane
• Can be done as CAPD (continuous abmulatory, manual exchanges by patient) or APD (automated, machine performs exchanges whilst asleep)

Question 4

What are the clinical consequences of HD?

Answer 4

• ‘Crash’ hypotension (when more fluid is removed from circulating volume than the body can repopulate)
• Dialysis disequilibrium
• Craps
• Fatigue
• Hypokalaemia
• Air embolism
• Blood loss
• Access problems

Question 5

What are the clinical consequences of PD?

Answer 5

• Infection (peritonitis)
• Glucose load (development or worsening control of diabetes)
• Mechanical (hernia, diaphragmatic leak, dislodged catheter)
• Peritoneal membrane failure
• Hypoalbuminaemia
• Encapsulating peritoneal sclerosis
• Not suitable for obese, intra-abdominal adhesions, frail or if home not suitable

Question 6

What immunosuppressants are used in renal transplantation?

Answer 6

• Cyclosporins
• Tacrolimus
• MPA

Question 7

What are the pros to transplantation?

Answer 7

• No dialysis
• Better level of renal function
• Can live much more independently
• Better life expectancy
• Fertility better

Question 8

What are the cons to renal transplantation?

Answer 8

• Immunosuppressive medication for duration of transplant
• Increased cardiovascular risk
• Increased infection
• Post transplant diabetes
• Skin malignancies and others

Question 9

Indications for chronic dialysis

Answer 9

• ESRF
• Any of acute indications continuing long-term