Renal Replacement Therapy Flashcards
State the 3 types of dialysis
-
Peritoneal dialysis
- Continuous ambulatory
- Automated
-
Haemodilaysis
- Hospital/unit based
- Home HD
- Nocturnal HD
- Continuous renal replacement therapy (ITU)
- Haemofiltration
Explain how peritoneal dialysis works
Dialysis solution, containing dextrose, added to peritoenal cavity and peritoneal membrane acts as filtration membrane. Osmotic gradient created by high concentration of glucose the dialysate fluid helps the movement of water and solutes across peritoneal membrane.
What catheter is required for peritoneal dialysis?
Tenckhoff catheter (allow you to put fluid in and out of peritoneal cavity)
There are two subtypes of peritoneal dialysis; describe these
Continuous Ambulatory Peritoneal Dialysis
- Dialysis solution in peritoneum at all times
- Often put 2L in and change this 4-5 times throughout day
Automated Peritoneal Dialysis
- Machine continously replaces dialysis fluid in peritoneum over night
- Trained healthcare assistants can visit pts home to help set up APD (assisted automated PD)
- Takes 8-10hrs
State some advantages of peritoneal dialysis
- Don’t have to go into hospital 3x per week- better quality o flife
- Regime can be made to suit individual
- Fewer dietary restrictions
State some disadvantages of peritoneal dialysis
- Pt needs to be able to manage their own care
- Unsuitable for pts with stoma or previous surgery
- Risk of infection
- Ultrafiltration failure and weight gain (this occurs when pt starts to absorb dextrose in the dialysis solution- reduces filtration gradient so ultrafiltration less effective and can lead to weight gain)
- Peritoneal sclerosis
- Psychological/body image problems
- Ince
Whats the difference between haemodialysis and haemofiltration?
- Haemodialysis: blood and dialysate flow in opposite direction. Rate of filtration fasterbut pt can feel very light headed and there is longer recovery
- Haemofiltration: blood and dialysate flow in same direction. Rate of transfer slower but decreased side effects
State some advantages of haemodialysis
- Efficient form of dialysis
- Unit based hence lots of support from staff
State some disadvantages of haemodialysis
- Have to visit hospital about 3x per week for few hours at a time
- Infection
- Muscle cramps
- Haematomoas/risk of bleeding
- Aneamia due to clotted lines/haemolysis
- More dietary and fluid restrictions
- Haemodynamic instability
- Reaction to dialysers
State two options, in terms of vascular access, for heamodialysis
- Tunnelled cuffed catheter
- Arteriovenous fistula
Describe how a tunnelled cuffed catheter works
Tube inserted into subclavian or jugular vein with tip that sits in SVC or right atrium. Has two lumens (one for blood entry and one for blood exit). Dacron cuff surrounds catheterto promoste healing and adhesion of tissue to cuff- reduce risk of infection.
State some complications of a tunnelled cuffed catheter
- Infection
- Thrombosis
Describe how an arteriovenous fistula works
Artificial connection between an artery to a vein. Blood bypasses capillary system and allows blood under high pressure from artery directly to vein; provides permanent, large, easily accessible blood vessel with high pressure flow. Requires operation to form fistula and 4week to 4 month maturation period without use
State some complications of an AV fistula
- Aneuryseum
- Infection
- Thrombosis
- Stenosis
- STEAL syndrome
- High output cardiac failure
What is STEAL syndrome?
Inadequete blood flow to limb distal to AV fistula as the AV fistula ‘steals’ blood from distal limb. Blood, that was supposed to supply distal limb, flows straight into venous system causing ischaemia.
Symptoms range from mild, such as a cold hand, to severe ischemia with rest pain, neurologic deficit, and tissue loss
Explain how an AV fistula can cause high output cardiac failure
Blood is flowing very quickly from the arterial to venous system via the fistula. Consequently, there is a rapid return of blood to the heart. This increases preload in heart and leads to hypertrophy and hence heart failure
What 4 things should you look for when examining an AV fistula?
- Skin integrity
- Aneuryseums
- Palpable thrill
- Sterotypical ‘machinery murmur’ on auscultation
State 2 indications for long term dialysis
- CKD stage 5 (ESRF)
- Any of acute indicatios continuing long term e.g. acidosis, electrolyte distrubance, intoxication, oedema, uraemia
State some indications for acute dialysis
*Think AEIOU
- Acidosis not responding to treatment
- Electrolyte abnormalities not responding to treatment
- Intoxication
- Oedema not responding to treatment
- Uraemia symptoms such as seizures or reduced consciousness
Transplantation is the treatment of choice for most pts with ESRF; discuss advantages & disadvantages of renal transplantation
Advantages
- Near normal lifestyle
- Better mortality/morbidity
Disadvantages
- Must meet criteria
- Compliance with lifelong medication
- Risk of rejection
- Risk of infection (as on immunosupressants)
- Risk of malignancy
- Long wait times
What does evidence suggest about those are >80yrs and have a WHO performance score of 3 or more in terms of renal transplantation?
Renal transplant offers no benefit. Often these pts chose not to have invasive therapy such as PD, HD… hence we do active conservative management of ESRF.
- Control symptoms
- Advanced care planning
- Support for pt and family
State some contraindications for kidney transplantation
- Active infection
- Malignancy
- Severe heart disease
- Severe lung disease
- Reversible renal disease
- Uncontrolled substance absuse
- On-going treatment & non-adherence
- Short life expectancy
State 3 possible donor types for renal transplantation
- Living related donor
- Living unrelated donor
- Deceased donor
What is the best possible donor type for renal transplant?
Living related donor
Most of renal transplantations in UK use which type of donor?
Deceased donor (60%)
Discuss the disadvantages of deceased donor transplantation
- Pt has little time to prepare
- Survival of kidney allografts and pts are lower compared to live donor transplants
State and describe the subtypes of living unrealted donor transplantations
*Don’t worry about too much
- Live donor paired exchange: when you have a relative or friend who is willing and able to be a kidney donor, but he or she is not a match for you. In a paired exchange, your relative or friend gives a kidney to someone who needs it, and that recipients’ relative or friend gives his or her kidney to you.
- Live donor/deceased donor paired exchange:
- Live donor chain
- Altruistic donation
Renal transplantation requires immunosupressive therapy. Potent induction treatment is required followed by maintenance therapy. State some examples of immunsupressant medications used
Usual immunosupressant routine:
- Tacrolismus
- Mycophenolate
- Prednisolone
Other possible immunosupressants:
- Azathioprine
- Sirolimus
- Cyclosporin
Discuss what is involved in long term care of a transplant pt
- Frequent check ups
- Frequent monitoring (GFR, Ca2+, phosphate, PTH, lipids, glucose)
- Screening for infections
- Vaccinations
- Screen for malignancies
- Contraception is obligatory in first year
State some potential complications of renal transplantation
