Renal - Dialysis

Question 1

When is dialysis used?

Answer 1

End-stage renal failure

Complications of AKI

Question 2

When is short-term dialysis used?

Answer 2

AEIOU

Acidosis (severe and not responding to treatment)
Eelectrolyte imbalance (treatment-resistant hyperkalaemia)
Intoxication
Oedema (severe pulmonary oedema)
Uraemia symptoms-

Question 3

What is the main indication of long-term dialysis?

Answer 3

End-stage renal failure
CKD stage 5

Question 4

How often is haemodialysis done?

Answer 4

4 hours a day 3 times a week

Question 5

How does haemodialysis work?

Answer 5

Blood passes through semipermeable membranes

Solutes filter out of the blood into fluid dialysate

Concentration gradient between blood and dialysate causes water and solutes to diffuse across the membrane

Anticoagulation with citrate or heparin to prevent blood clotting in the machine

Question 6

What options are there for longer-term haemodialysis access?

Answer 6

Tunnelled cuffed catheter
Arteriovenous fistula

Question 7

What is a tunnelled cuffed catheter?

Answer 7

Catheter inserted into subclavian or jugular vein with a tip in superior vena cava or RA

Two lumens, one for blood exiting body (RED)

One for blood entering the body (BLUE)

Question 8

What cuff is used in a tunnelled cuffed catheter?

Answer 8

Dacron cuff surrounds the catheter

Promotes healing and adhesion of tissue, making the catheter more permanent

Provides a barrier to infection

Question 9

What are the risks of a tunnelled cuffed catheter?

Answer 9

Infection and blood clots within the catheter

Question 10

What is an arteriovenous fistula?

Answer 10

Artificial connection between an artery and a vein

Bypasses capillary system and allows blood to flow under high pressure from the artery directly into the vein

Permanent, large, easy-access blood vessel with high-pressure arterial blood flow

Question 11

How is an AV fistula created?

Answer 11

Surgically, requires 4-16 weeks before use

Radiocephalic fistula (wrist)

Brachiocephalic fistula (antecubital fossa)

Brachiobasilic fistula (upper arm)

Question 12

How do you examine an AV fistula?

Answer 12

Skin integrity
Aneurysms
Palpable thrill (over anastomosis)
Machinery murmur (over fistula)

Question 13

What are the complications of an AV fistula?

Answer 13

Aneurysm
Infection
Thrombosis
Stenosis
STEAL syndrome
High-output HF

Question 14

What is STEAL syndrome?

Answer 14

Inadequate blood flow to limb distal to fistula

AV fistula steals blood from the rest of the limb

Blood diverted away from limb it was causing ischaemia

Question 15

What is High-output heart failure?

Answer 15

Blood flowing quickly from arterial to venous system through AV fistula

Rapid return of blood to the heart

Increases pre-load causing hypertrophy leading to HF

Question 16

What is peritoneal dialysis?

Answer 16

Peritoneal membrane to filter the blood

Dialysis solution (containing dextrose) added to peritoneal cavity

Ultrafiltration occurs from the blood across the peritoneal membrane

Question 17

What does peritoneal dialysis involve?

Answer 17

Tenckhoff catheter
Catheter inserted into peritoneal cavity, one end on the outside

Allows access to the peritoneal cavity to insert and remove dialysis solution

Question 18

What is continuous ambulatory peritoneal dialysis (CAPD)?

Answer 18

Dialysis solution always in the peritoneal cavity

Regimes for changing solution, e.g. two litres of solution replaced QD

Question 19

What is automated dialysis?

Answer 19

Machine replaces dialysis fluid for 8-10 hours overnight

Question 20

What are the complications of peritoneal dialysis?

Answer 20

Bacterial peritonitis (high sugar environment)
Peritoneal sclerosis
Ultrafiltration failure (dextrose absorbed, reducing filtrate gradient)
Weight gain (dextrose absorption)
Psychosocial implications