Dialysis

Question 1

Indictaions for short-term dialysis?

Answer 1

Acidosis (severe and not responding to treatment)
Electrolyte abnormalities (treatment resistant hyperkalaemia)
Intoxication (overdose of certain meds)
Oedema (severe an dunresponsive pulmonary oedema)
Uraemia symptoms such as seizures or reduced consciousness

Question 2

Main indication for long term dialysis?

Answer 2

End-stage renal failure (CKD stage 5)

Question 3

2 options for long term dialysis?

Answer 3

• Haemodialysis
• Peritoneal dialysis

Question 4

In haemodialysis what is given for anticoagulation?

Answer 4

Citrate or heparin

Question 5

Options for long term access to the blood supply in haemodialysis are?

Answer 5

• Tunnelled cuffed catheter
• Arteriovenous fistula

Question 6

Where is a tunnelled cuffed catheter inserted?

Answer 6

Into the subclavian or jugular vein with a tip in the superior vena cava or right atrium

Dacron cuff surrounds the catheter- promotes healing and adhesion of tissue, making the catheter more permanent and provides a barrier to infection

Question 7

What is an arteriovenous fistula and types of them?

Answer 7

Artifical connection betwen artery and vein
Allows blood to flow under high pressure from the artery directly into the vein

Requires surgical operation and maturation period of 4-16 weeks before it can be used

Options are:
* Radiocephalic fistula at the wrist (radial artery to cephalic vein)
* Brachiocephalic fistula at the antecubital fossa (bracial artery to cephalic vein)
* Brachiobasilic fistula at the upper arm (less common and a more complex operation)

Question 8

Av fistula features to examine in an OSCE are?

Answer 8

• Skin integrity
• Aeurysms
• Palpable thrill (a fine vibration felt over the anastomosis)
• Machinery murmur on auscultation over the fistula

Question 9

Complications of an AV fistula?

Answer 9

• Aneurysm
• Infection
• Thrombosis
• Stenosis
• STEAL syndrome
• High-output heart failure

Question 10

What is STEAL syndrome?

Answer 10

Occurs when there is inadequate blood flow to the limb distal to the fistula leading to ischaemia

Question 11

What is high output heart failure?

Answer 11

Caused by blood flowing quickly from the arterial to the venous system through an AV fistula
There is rapid return of blood to the heart, increasing the pre load= hypertrophy of the heart muscle and heart failure

Question 12

What does peritoneal dialysis involve?

Answer 12

Uses the peritoneal membrane to filter the blood
Involves a Tenckhoff catheter (plastic tub inserted into the peritoneal cavity)

Question 13

What is continuous ambulatory peritoneal dialysis (CAPD) compared to automated dialysis?

Answer 13

Where dialysis solution is always in the peritoneal cavity
Automated- machine continuously replaces teh dialysis fluid for 8-10 hours overnight

Question 14

Complications of peritoneal dialysis?

Answer 14

• Bacterial peritonitis (infections in the high sugar environment are common and serious)
• Peritoneal sclerosis (thickening and scarring of the peritoneal membrane)
• Ultrafiltration failure (dextrose is absorbed, reducing the filtration gradient, making ultrafiltration less effective)
• Weight gain (due to absorption og the dextrose)
• Psychosocial implications