Renal Replacement Therapy Flashcards
(13 cards)
When should dialysis be commenced?
Inability to control volume status Inability to control blood pressure Acid-base electrolyte abnormalities not controlled Nausea and committing Cognitive impairment
GFR around 5-10 when commenced
What are the options for RRT?
HAemodialysis
Peritoneal dialysis
Transplantation
Describe haemodialysis
Blood is passed over a semi-permeable membrane against dialysis fluid flowing int he opposite direction.
Diffusion of solutes occurs down the concentration gradient.
A hydrostatic gradient is under to clear excess fluid as required.
Access is preferentially via an arteriovenous fistula which provides increased blood flow and longevity.
This should be created prior to need for RRT to avoid infection risk associated with central venous dialysis catheters.
It is needed 3 times/week or more.
Daily HD improves outcomes.
What are problems with haemodialysis
Access (arteriovenous fistula: thrombosis, stenosis; tunnelled venous ine - infection, blockage, recirculation of blood
Dialysis disequilibrium - between cerebral and blood solutes leading to cerebral oedema –> start gradually
Hypotension
Time consuming
Describe peritoneal dialysis
Uses the peritoneum as a semi-permeable membrane.
Catheter is inserted into the peritoneal cavity and fluid infused.
Solutes diffuse across slowly.
Ultrafiltration is achieved by adding osmotic agents (clearing excess fluid as required)
Continuous process with intermittent drainage and refilling of the peritoneal cavity performed at home
What are problems with peritoneal dialysis?
Catheter site infection
Peritonitis
Hernia
Loss of membrane function over time
What are complications of RRT?
CVS disease:
PRoteint-calorie malnutrition
Renal bone disease
Infection
When should transplantation be considered?
Every patient with or progressive toward stage 5 kidney disease
What are contraindication to transplantation?
Absolute: cancer with metastases
Temporary: Active infection, HIV with viral replication, unstable CVD
Relative: congestive heart failure
What are the types of graft?
Living donor - best graft function and survival
Deceased donor:
1 Donor after brain death
2 Expanded criteria donor from an older kidney or from a patient with history of CVA or CKD
3 Donor after cardiac death
What drugs are used for immunosuppression in transplant?
Ciclosporin: inhibits calcineurin involved in T cell activation and proliferation
Tacrolimus: inhibits calcineurin involved in T cell activation and proliferation
Mycophenolate: antimetabolites - blocks purine synthesis, inhibits proliferation of B and T cells. SE: GI toxic, marrow suppression - anaemia, leucopenia
What drugs are used for immunosuppression in transplant?
Ciclosporin: inhibits calcineurin involved in T cell activation and proliferation
Tacrolimus: inhibits calcineurin involved in T cell activation and proliferation
Mycophenolate, azathioprine: antimetabolites - blocks purine synthesis, inhibits proliferation of B and T cells. SE: GI toxic, marrow suppression - anaemia, leucopenia
Glucorticosteroids
Reduced transcription of inflammatory cytokines, first line for rejection
Monoclonal antibodies - ‘-mab’ Selectively block activated T cells/T cell Bell depletion
What are complications of renal transplant?
Surgical: bleed, thrombosis, infection Delayed graft function Rejection - antibody mediated or cellular - treatment with high dose steroids and immunosuppression Infection Malignancy due to immunosuppression CVD
