Renal Replacement Therapy Flashcards
Define dialysis:
A method of artificial filtration in place of the kidneys which involves removing waste products, fluid and solutes.
What are some of the indications for acute dialysis?
Use mnemonic AEIOU: Acidosis Electrolyte imbalances Intoxication Oedema Uraemia
What are the main indications for long term dialysis?
End stage renal failure (usually from CKD)
When any acute problems become long term
What are the three main options for long term dialysis?
Continuous ambulatory peritoneal dialysis
Automated peritoneal dialysis
Haemodialysis
What form of dialysis can be used in the acute / short term setting?
Haemofiltration
In peritoneal dialysis, what acts as the filtration membrane?
The peritoneal membrane
What is the basic mechanism behind peritoneal dialysis?
1) The peritoneal cavity is filled with a special dialysis solution
2) Ultrafiltration occurs across the peritoneal membrane from the blood to the solution
3) Dialysis solution is then taken away and replaced
What form of catheter is used in peritoneal dialysis?
Tenckhoff Catheter - used for inserting and removing the dialysis solution
How does automated dialysis occur in peritoneal dialysis?
The peritoneal dialysis occurs overnight. A machine constantly replaces the dialysis fluid in the abdomen overnight to optimise ultrafiltration.
Takes roughly 8-10 hours
List some of the main complications of peritoneal dialysis?
- Bacterial Peritonitis
- Peritoneal sclerosis
- Ultrafiltration failure
- Weight gain
- Psychosocial impacts
Why is bacterial peritonitis a common S/E in peritoneal dialysis?
Infusions of glucose solutions allow the peritoneum to become a great environment for bacterial growth
What are the two main options for accessing a good blood supply in haemodialysis?
AV fistula
Tunneled cuff catheter
How regular can haemodialysis be for a patient?
Roughly 4 hours 3 times a week
Where is a tunnelled cuffed catheter usually placed?
Subclavian or jugular vein
Tip sits in the SVC or right atrium
There are two lumens in a tunnelled cuffed catheter, red and blue. WHy?
Red - blood exits the body
Blue - blood re enters the body
What is the purpose of the Dracon ring?
This is inserted around the catheter to promote healing and adhesions of the tissue to the cuff to allow for it to be more permanent. It also reduces bacterial infection risk
What are the main complications of a Tunnelled cuffed catheter?
Bacterial infections
Clots
What vessels are typically used to make an AV fistula?
Brachio-cephalic
Radio-cephalic
Brachio-basilic (rarer)
What is typically heard on auscultation of an AV fistula?
Continuous machinery murmur
How long does an AV fistula take to mature?
Anywhere from 4 weeks to 4 months
What are some of the complications of an AV fistula?
Aneurysms Infection Thrombosis Stenosis STEAL syndrome High output heart failure
What is STEAL syndrome?
This is when there is inadequate flow to the lower limb below the AV fistula as the fistula STEALS blood from it and diverts it straight to the venous system
Limb ischaemia occurs
How does high output heart failure occur in AV fistulas?
Blood flows very quickly from arterial to venous system through the fistula
Rapid return of blood to heart
Increased preload on heart
Hypertrophy of heart muscle muscle — heart failure
What is the mortality rate of dialysis?
20% on average yearly
