Renal Replacement Therapy

Question 1

What types of RRT have we got?

Answer 1

Dialysis

• haemodialysis
• peritoneal dialysis

Transplant

Question 2

What is haemodialysis?

Answer 2

A machine is used to filter the blood

Question 3

Describe the process of haemodialysis?

Answer 3

Patient’s blood is removed from the body

Flows into the dialyser

Waste products flow out of blood, useful products flow from dialysate to blood

Blood returned to body

Question 4

Describe how the dialyser works?

Answer 4

It is a tube with millions of hollow fibres

Blood flows one way and dialysate flows the other way

Products flow across between the fluids

Question 5

What products go from the blood to the dialysate?

Answer 5

Potassium
Phosphate
Urea
Excess water

Question 6

What products go from the dialysate to the blood?

Answer 6

Bicarbonate
Calcium
Sodium

Question 7

What is an arteriovenous fistula?

Answer 7

A connection between an artery and vein

It creates a large vessel that is stronger and at a higher pressure than a normal vein, so is able to withstand being used for dialysis

Question 8

List some types of AV fistula?

When would they be used?

Answer 8

Standard AV fistula: in most cases, used unless contra-indicated

Synthetic graft AV fistula: in people with less healthy blood vessels; elderly, arteriopaths

Catheter straight into the right ventricle of the heart via the jugular vein: in emergencies

Question 9

Why can’t you use a standard AV fistula in an emergency?

Answer 9

Because once it is created it takes a few months before it is ready for use

Question 10

Where can you do haemodialysis?

Compare duration of each session and how frequently it has to be done in each place

Answer 10

In hospital or at a satellite unit
- longer, less often

At home
- shorter, more often

Question 11

What adverse effects do patients sometime experience during dialysis?

Answer 11

Hypotension / cramps
Nausea / headaches
Chest pain
Fever

Question 12

What are some severe complications of haemodialysis?

Answer 12

Heparin Induced Thrombocytopenia: platelet deficiency

Amyloidosis

Question 13

What is peritoneal dialysis?

Answer 13

Uses the patient’s peritoneum in the abdomen as a membrane

Across which fluids and solutes are exchanged into and out of the blood

Question 14

Describe how peritoneal dialysis works?

Answer 14

Tube sits in lower abdomen

The dialysate flows into peritoneal cavity

It is left to sit there for a few hours

Waste products diffuse from the peritoneal capillaries into the dialysate

Useful products diffuse from the dialysate to the capillaries

The dialysate is drained off

Question 15

What are the 2 types of peritoneal dialysis?

Answer 15

CAPD: continuous ambulatory peritoneal dialysis

• you put the fluid in and drain it manually
• do it during the day

APD: automated peritoneal dialsys

• machine does the draining and filling
• do it overnight

Question 16

What does CAPD stand for?

Answer 16

continuous ambulatory peritoneal dialysis

Question 17

What does APD stand for?

Answer 17

Automates peritoneal dialysis

Question 18

Which type of people choose each type of dialysis?

Answer 18

Haemo:

• those who lack the mental ability and dexterity to work machines themselves
• elderly people
• those who live alone

Peritoneal:

• those with jobs
• people who are able to work the machines
• younger people, they can mainatin their independence

Question 19

What are the complications of peritoneal dialysis?

Answer 19

Infection of peritoneum
Abdominal wall herniation
Intestinal perforation

Question 20

Which patients are suitable for transplant?

Answer 20

eGFR less than 15

No other serious medical conditions

Question 21

What is better about a transplant compared with dialysis?

Answer 21

Survival advantage

Quality of life is better

Economic advantage to NHS

Successful pregnancy with transplant, not dialysis

Question 22

What are the problems with transplant?

Answer 22

Rejection: vital to get correct match

Lifelong immunosuppressants

Don’t last forever