dyalisis

Question 1

what does diffusion allow in dialysis?

Answer 1

this allows removal of toxins which build up with ESKD:

• urea and creatinine
• potassium
• sodium

allows the infusion of bicarbonate

Question 2

what does flow rate need to be for dialysis and how may it be achieved?

Answer 2

300- 350 mls/min

Vascular access using:

• arteriovenous fistula (AVF)
• arteriovenous graft (AVG)
• tunnelled central venous cetheter (TCVC)
• temporary venous catheter (vascath)

Question 2

what does flow rate need to be for dialysis and how may it be achieved?

Answer 2

300- 350 mls/min

Vascular access using:

• arteriovenous fistula (AVF)
• arteriovenous graft (AVG)
• tunnelled central venous cetheter (TCVC)
• temporary venous catheter (vascath)

Question 3

what is ultrafiltration in dialysis?

Answer 3

-the movement of water and all solutes dissolved in it, known as convection solute drag across a semi permeable membrane in response to a pressure gradient is known as ‘ultrafiltration’ in dialysis

Question 4

what does adsorption affect?

Answer 4

• plasma proteins and any solutes that might be bound to them
• plasma proteins (especially those of low molecular weight) stick to the membrane surface and are removed by membrane binding
• high flux membranes adsorb protein bound solutes better than low flux membranes

Question 5

what is the nature of haemodiafiltration?

Answer 5

-it is increasingly convective in nature

Question 6

what is dialysis?

Answer 6

• a method for performing the filtration tasks of the kidneys artificially in patients with end stage renal failure or complications of renal failure
• it involves removing excess fluid, solutes and waste products

Question 7

what are indications for acute dialysis?

Answer 7

AEIOU

• Acidosis (severe and not responding to treatment)
• Electrolyte abnormalities (severe + unresponsive hyperkalaemia)
• Intoxication (overdose of certain medications)
• Oedema (severe and unresponsive pulmonary oedema)
• Uraemia (symptoms such as seizures or reduced consciousness)

Question 8

what are indications for long term dialysis?

Answer 8

• end stage renal failure (CKD stage 5)

- any of the acute indications continuing long term

Question 9

what are the options of maintenance dialysis?

Answer 9

• continuous ambulatory peritoneal dialysis
• automated peritoneal dialysis
• haemodialysis

Question 10

what is used as the filtration membrane in peritoneal dialysis?

Answer 10

-the peritoneal membrane

Question 11

how does peritoneal dialysis work?

Answer 11

• it uses the peritoneal membrane as the filtration membrane
• a special dialysis solution containing dextrose is added to the peritoneal cavity
• ultrafiltration occurs from the blood, across the peritoneal membrane and in to the dialysis solution
• the dialysis solution is then replaced, taking away the waste products that have filtered out of the blood into the solution

Question 12

what catheter is used in peritoneal dialysis?

Answer 12

Tenckhoff catheter

Question 13

what are the different types of peritoneal dialysis?

Answer 13

• continuous ambulatory peritoneal dialysis

- automated dialysis

Question 14

what’s the difference between continuous and automated dialysis?

Answer 14

continuous- the solution is in the peritoneum at all times, there are various regimes for changing the solution

automates- involves peritoneal dialysis occurring overnight. A machine continuously replaces dialysis fluid in abdomen overnight to optimise ultrafiltration

Question 15

what are some complications of peritoneal dialysis?

Answer 15

• bacterial pericarditis
• peritoneal sclerosis
• ultrafiltration failure
• weight gain
• psychosocial effects

Question 16

how long and how often is haemodyalisis?

Answer 16

• usually 4 hours long

- 3 sessions a week

Question 17

what are the options for haemodyalisis?

Answer 17

• tunnel cuffed catheter

- anterior venous fistula

Question 18

where is a tunnels cuffed catheter inserted?

Answer 18

-into the subclavian or jugular vein with a tip that sits in the superior vena cava or right atrium

Question 19

what is the Dacron cuff?

Answer 19

• a ring that surrounds the catheter in the tunnelled cuffed catheter
• it promotes healing and adhesion of tissue to the cuff making the catheter more permanent and providing a barrier to bacterial infection

Question 20

what are the main complications within the tunnelled cuffed catheter?

Answer 20

-infection and blood clots within the catheter

Question 21

what is an A-V fistula?

Answer 21

• an artificial connection between an artery to a vein
• it bypasses the capillary system and allows blood to flow under high pressure from the artery directly into the vein
• this provides a permanent, large, easy access blood vessel with high pressure arterial blood flow

Question 22

what is required to create an A-V fistula?

Answer 22

-surgical operation and a 4 week to 4 month maturation period without use

Question 23

where is the A-V fistula normally formed between?

Answer 23

Radio- cephalic
Brachio- cephalic
Brachio- basilic (less common and more complex)

Question 24

what should be done to examine A-V fistula?

Answer 24

• skin integrity
• aneurysms
• palpable thrill
• stereotypical ‘machinery murmur’ on auscultation

Question 25

what are A-V fistula complications?

Answer 25

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