Renal Replacement Therapy 1 (Dialysis)

Question 1

What are the symptoms of uraemia?

Answer 1

Malaise/exhaustion

Sleeping too much

Question 2

What are the biochemical investigations of renal disorders?

Answer 2

FBC

ESR

U&E’s

Urinalysis

Blood & Urine culture

ABG

Question 3

What are the principles of dialysis?

Answer 3

The solute compisition of a fluid A is altered by exposing the fluid to a second fluid B, via a semipermeable membrane

1st principle of Dialysis - Diffusion

Particles move across the semipermeable membrane in order to balance the concentration

2nd principle of Dialysis - Ultrafiltration

Particles moves across semipermeable membrane in order to balance concentration, some fluid is also removed

• Dialysis removes Creatinine and Urea
• Dialysis replaces lost particles such as Na+, Bicarbonate

Question 4

What are the different modalities of dialysis and briefly explain how they work?

Answer 4

Haemodialysis:

• Blood pumped into filter at opposite end from dialysate so that blood has a chance to be filtered
• Once blood has been filtered by dialysate it is returned into the patients body

Peritoneal dialysis:

• Dialysis solution is put into the peritoneal cavity using the peritoneum as a dialysis membrane
• After a dwell time the fluid is drained and a fresh dialysate is instilled
• Dialysate fluid contains a balanced concentration of electrolytes (glucose most common for ultrafiltration)

Question 5

How are dialysis patients managed and what are the complications of dialysis?

Answer 5

Fluid restriction (allowed urine output + insensible loss)

Dietary restriction (no potassium, sodium or phosphate)

Haemodialysis complications:

CVS problems (arrythmias)

Coagultation

Peritoneal dialysis complications:

Infection

Tube malfunction