3: Dialysis

Question 1

Which three process are involved in dialysis?

Answer 1

Diffusion

Convection

Adsorbption

Question 2

What builds up in end stage kidney disease and needs to be removed by dialysis?

Answer 2

Toxins

urea, sodium, potassium

Question 3

How is metabolic acidosis associated with end stage kidney disease corrected?

Answer 3

Sodium bicarbonate

Question 4

What passes from the dialyte to the blood by diffusion to correct metabolic acidosis?

Answer 4

Sodium bicarbonate

Question 5

Why does end stage kidney disease cause metabolic acidosis?

Answer 5

Kidneys can’t filter H+

Question 6

How is the movement of water controlled in dialysis?

Answer 6

Convection / ultrafiltration

controlled by altering the pressure rather than the conc. gradients of electrolytes

Question 7

How is the transport of plasma proteins controlled in dialysis?

Answer 7

Size of the pores in the dialyser

by absorption

Question 8

Which processes control

a) electrolyte
b) water
c) plasma protein

transport in dialysis?

Answer 8

a) Diffusion (solute gradients)

b) Convection / ultrafiltration (pressure gradient)

c) Absorption (size of the pores)

Question 9

How long do patients tend to be on haemodialysis for per week?

Answer 9

4 hours

3 times a week

minimum

Question 10

What lifestyle restrictions are put on patients on dialysis?

Answer 10

Fluid restriction

Salt restriction

Question 11

Which electrolyte imbalances are people with CKD at risk of?

Answer 11

Hypernatraemia (> fluid overload)

Hyperkalaemia (>arrythmia)

Hyperphosphataemia (bone disease)

so they’re all restricted

Question 12

How is a patient hooked up to haemodialysis?

Answer 12

Fistula

artery and vein joined together (e.g radial artery & bacilic vein)

Question 13

What are complications of using a fistula for dialysis?

Answer 13

Stenosis

Thrombosis

regularly reviewed

Question 14

Fistulas are (planned / emergency) procedures for people with CKD.

Answer 14

planned operation

no good in emergency presentations

Question 15

How is dialysis given to patients with emergency presentations of CKD / renal failure?

Answer 15

Tunneled venous catheter

internal jugular or femoral vein

Question 16

What is a complication of using a tunneled venous catheter for dialysis?

Answer 16

Infection

Question 17

Which organism usually causes infections associated with tunneled venous catheters?

Answer 17

Staph aureus

Question 18

Which antibiotics are given for dialysis line infections?

Answer 18

IV vancomycin

Question 19

Apart from infection, what are possible complications of dialysis?

Answer 19

Hypotension - decrease in blood volume due to filtration

Haemorrhage from ruptured fistula

Question 20

How does peritoneal dialysis work?

Answer 20

Peritoneum has loads of capillaries

Fluid into peritoneal cavity, comes into close contact with capillaries

Question 21

How are

a) solutes
b) water

removed from the blood by peritoneal dialysis?

Answer 21

a) Diffusion (high > low)

b) Osmosis (dialysate has high glucose conc.)

Question 22

Why is glucose included in the dialyte in peritoneal dialysis?

Answer 22

Increases the osmolarity of the dialyte, encouraging osmosis FROM the peritoneal capillaries

The peritoneal capillaries contain glucose themselves and so have their own osmolarity which needs to be overcome

Question 23

How often are patients given continuous (bags) peritoneal dialysis for?

How long does each session take?

Answer 23

QDS

20-30 mins

Question 24

What types of peritoneal dialysis are given

a) throughout the day
b) at night?

Answer 24

a) Continuous

b) Automated

Question 25

Which bacteria can cause infection in patients on peritoneal dialysis?

Answer 25

Skin commensals (staph, strep)

Gut commensals (E. coli, klebsiella)

Question 26

What are GI complications of peritoneal dialysis?

Answer 26

Hernia

Peritonitis

Question 27

What are common causes of death in people on dialysis?

Answer 27

CVD - MI, stroke

Infection