Renal Replacement Therapy

Question 1

What is dialysis?

Answer 1

diffusion across a semipermeable membrane

Question 2

What is the purpose of dialysis?

Answer 2

removal of toxins which build up-urea, potassium and sodium; infusion of bicarbonate

Question 3

What blood flow rate do you need for haemodialydid?

Answer 3

300mls/min

Question 4

What is filtration in haemodialysis?

Answer 4

the removal of water due to a pressure gradient

Question 5

What is the recommended time of dialysis per week?

Answer 5

4 hours 3xweek

Question 6

What happens if patients have less than 12 hours a week?

Answer 6

increased 1% risk of death for every 30 minutes les dialysis

Question 7

What are the dietary restrictions on patients on dialysis?

Answer 7

fluid- 1litre per day; low salt diet; low potassium diet; low phsophate diet

Question 8

What foods contain high amounts of potassium?

Answer 8

bananas; chocolate; potatoes; avocado

Question 9

What is the gold standard fr dialysis access?

Answer 9

AV fistula

Question 10

Waht is an AVfistula?

Answer 10

joins an artery and veine to make an enlarged thick walled vein

Question 11

What are the pros of AV fistulas?

Answer 11

good bloof flow and unlikely to cause infection

Question 12

What are the cons of AV fistula?

Answer 12

surgery and 6 weeks maturation; can limit blood flow to distal arm

Question 13

What is a tunneled venous catheter?

Answer 13

a catheter inserted into a large vein- jugular, subclavian or femoral

Question 14

What are the pros of a tunneled venous catheter?

Answer 14

easy to insert and can be used immediately

Question 15

What are the cons of a tunneled venous catheter?

Answer 15

high risk of infection; can cause vein damage making replacements difficult; become blocked

Question 16

What can untreated infection lead to in tunneled venous catheters?

Answer 16

endocarditis or discitis

Question 17

What are the investigations if a tunneled venous catheter is suspected infected?

Answer 17

blood cultures; FBC and CRP; exit site swab

Question 18

What is the treatment for infected tunneled venous catheters?

Answer 18

vancomycin and line removal/exchange

Question 19

What is intradialytic hypotension?

Answer 19

removing large volumes of water can lead to underfilling of the intravascular space if done too quickly and low BP

Question 20

How does peritoneal dialysis work?

Answer 20

solute removal by diffusion of solutes across the peritoneal membrane; water removal by osmosis driven by high glucose conc in dialysate fluid

Question 21

what are the 2 types of peritoneal dialysis?

Answer 21

continuous peritoneal dialysis and automated peritoneal dialysis

Question 22

How does CAPD work?

Answer 22

4 bag exchanges per day, fluid drained then fresh fluid instilled- 1/2 hour per exchange

Question 23

How does APD work?

Answer 23

1 bag of fluid stays in all day and overnight machine drains fluid in and out for 9-10 hours per night

Question 24

What are the sources of infection with peritoneal dialysis?

Answer 24

contamination; gut bacteria translocation

Question 25

What is the treatment for infection in peritoneal infections?

Answer 25

culture PD fluid; intraperitoneal abx

Question 26

What are other problems associated with PD?

Answer 26

membrane failure and hernias

Question 27

What happens if there is membrane failure with PD?

Answer 27

inability to remove enough water so pt becomes fluid overloaded and needs to swithc to haemodialysis

Question 28

What causes hernias in PD?

Answer 28

increased abdo pressure due to peritoneal fluid

Question 29

What group of patients doesnt have a decreased survival with PD compared to haemodialysis?

Answer 29

under 60s with no comorbidities

Question 30

What are the metabolic complications associated with ESRD?

Answer 30

bone mineral metabolism; anaemia; sodium and water retention; accelerated CV disease

Question 31

What are patients started on dialysis?

Answer 31

if symptoms- fatiuge; itch; unresponsive fluid overload; N &V; LOA; bloods- resistant hyperkalaemia; GFR<5; UR>45; unresponsive acidosis

Question 32

What causes disequilibrium syndrome?

Answer 32

if dialyse patients too quickly, remove urea from blood but still left in brain so water moves osmotically into brain causing cerebral oedema and seizures