Renal replacement therapy Flashcards Preview

Renal and urology > Renal replacement therapy > Flashcards

Flashcards in Renal replacement therapy Deck (29):
1

What does dialysis do to the blood?

Removes toxins: urea, potassium, sodium

Allows infusion of bicarbonate

2

How does dialysis achieve removal of toxins and infusion of bicarbonate?

Diffusion via a semi-permeable membrane

 

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3

How does haemodialysis get rid of water?

Convection/filtration:

The movement of water (and all solutes dissolved in it) across a semipermeable membrane in response to a pressure gradient

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4

What is the minimum weekly amount of dialysis given to patients?

4 hours 3x weekly

5

What substances must patients reduce intake of when on dialysis and how is this achieved?

Fluid: if anuric 1litre per day (including food based fluid)

Salt: low salt diet to reduce thirst and help with fluid balance

Potassium: low potassium diet (bananas, chocolate, potatoes, avocado)

Phosphate: low phosphate diet and phosphate binders with meals (6-12 pills per day)
 

6

Why must patients restict intake of certain substances while on dialysis?

Kidneys normally excrete these things: on dialysis with kidneys not working, it is difficult ot remove them from the system

7

What is the gold standard method of creating vascular access for dialysis?

Creating an arteriovenous fistula

8

What are the benefits of creating an arteriovenous fistula for vascular access?

Good blood flow

Reduced likelihood of infection

9

What are the disadvantages of creating an arteriovenous fistula for vascular access?

Requires surgery

Requires maturation of about 6 weeks before can be used

Can limit blood flow to distal arm “steal”

Can block
 

10

How is a tunneled venous catheter used to get vascular access for dialysis?

A catheter inserted into a large vein: jugular, subclavian or femoral
 

11

What are the advantages of using a tunneled venous catheter for vascular dialysis access?

Usually easy to insert

Can be used immediately

12

What are the disadvantages of using a tunneled venous catheter for dialysis access?

High risk of infection

Can cause damage to veins making placing replacements difficult

Become blocked
 

13

What are the complications of an untreated infection from a tunneled venous catheter?

Endocarditis

Discitis

Death
 

14

What investigations should be done when infected tunneled venous catheter suspected?

Blood Cultures

FBC and CRP

Exit site swab
 

15

What is the treatment for an infected tunneled venous catheter?

Antibiotics: vancomycin

Line removal or exchange
 

16

What are some of the complications of haemodialysis?

Fluid overload

Blood leaks

Loss of vascular access

Hypokalaemia and cardiac arrest

Intradialytic hypotension

17

Why does interdialytic hypotension occur as a complication of haemodialysis?

Removing large volumes of H20 three times per week rather than continuously with normal kidneys leads to underfilling of the intravascular space and low BP
 

18

How does peritoneal dialysis work?

Solute removal by diffusion of solutes across the peritoneal membrane

Water removal by osmosis (water moving to equalise a concentration gradient) driven by high glucose concentration in dialysate fluid
 

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19

What is involved in continuous peritoneal dialysis (CAPD)?

Four bag exchanges per day

Fluid drained then fresh fluid instilled

½ hour per exchange
 

20

What is involved in automated peritoneal dialysis?

1 bag of fluid stays in all day

Overnight machine drains in and out fluid for 9-10 hours per night
 

21

What are the complications of intraperitoneal dialysis?

Infection

Membrane failure

Hernias

22

What kinds of infection might occur with intraperitoneal dialysis?

Peritonitis

Exit site infection

23

What are the causal organisms of infection with intraperitoneal dialysis?

Contamination: staphylococci, streptococci, diptheroids

Gut bacteria translocation: E. Coli, klebsiella

24

What is the treatment for intraperitoneal dialysis infection?

Culture PD fluid

Intraperitoneal antibiotics

May need catheter removed
 

25

What is membrane failure associated with intraperitoneal dialysis?

Inability to remove enough water so the patient becomes fluid overloaded

26

How is membrane failure associated with intraperitoneal dialysis managed?

Requires switch to haemodialysis

27

What blood results might indicate a patient needs to be started on dialysis?

Resistant hyperkalaemia

GFR <5

Urea >45

Unresponsive acidosis
 

28

Is there any difference in mortality if dialysis started earlier?

No

29

How long is the first session of haemodialysis?

2 hours