5.1: Dialysis Flashcards
True or false:
Most patients with CKD die before they reach end stage kidney disease?
TRUE
Most patients with CKD die before they reach end stage kidney disease (As CVS risk is increased)
Two treatments for end stage renal disease?
Dialysis
Transplantation
What is dialysis based on?
Based on the principle of diffusion
Movement of solutes from an area of high concentration to an area of low concentrations through a semi-permeable membrane
Eventually there is an equilibrium
What does dialysis do?
Removes toxins from the blood that build up in end stage kidney disease
- Urea
- Potassium
- Sodium
Also gives patients bicarbonate (if they have acidosis)
Describe how electrolytes move during dialysis?
Move across the semi-permeable membrane down a concentration gradient
How do you gain access for haemodialysis?
What is the blood flow per minute required?
300mls/min needed
AV Fistula
Describe what is happening in this picture?
Blood is being taken out of the body
Solutes pass out across the semi-permeable membrane
Blood passes back into the body
Describe the composition of Dialysate?
Pure Water
Sodium
Bicarbonate
Some potassium (to ensure we don’t remove all the potassium from the patient leading to stopping of the heart)
Glucose (Prevent hypo)
What happens to water before it enters the haemodialysis machine?
Why?
Water must be purified (a bit like a fish tank filtration system)
Prevents toxins entering the patients body and causing damage
How does haemodilaysis get rid of water?
Use of vacuum (negative pressure) to suck water across the membrane
This is called FILTRATION
This also removes some solutes dissolved in the water
How efficient is dialysis?
Not very
Longer treatment time equals better efficiency
Minimum time for dialysis in a week?
4 Hours
3 times a week
Describe the pros/cons for increasing and decreasing dialysis?
Decreased: 1% Increased risk of death for every 30mins less dialysis
However improved QoL (less time on it)
Increased: Potentially better survival
Decreased QoL
What restrictions are put on dialysis patients?
- Fluid Restriction (1l per day if anuric)
- Sodium Restriction (low salt diet)
- Potassium Restriction (Low potassium diet - bananas, chocolate, potatoes)
- Phosphate (Low Phosphate diet, phosphate binders)
Describe a fistula?
Joins and artery and a vein to make an enlarged thick walled vein called an Arteriovenous Fistula
This is where access for dialysis is gained