Kidneys: Dialysis and Transplantation Flashcards
How would you use Renal Replacement Therapy
- what is the gold standard
- what are the other forms
When would you use RRT
Ideally a living donor, can be deceased
Haemodialysis
- requires AV fistula formation
- can be done in home or hospital
Peritoneal dialysis (CCP/CAPD)
- allows independence
- not ideal for 5+ years
Preemptive transplantation
- uremic symptoms (fatigue, poor appetite, nausea)
- difficulty in controlling K, acidic pH, fluid volume
Indications for dialysis
Stage 4 => considered
Stage 5 => started as kidneys not compatible with life
Refractory hyperkalemia
Pulmonary edema, fluid overload resistant to diuretics
Uremia - systemic presentation
-pericarditis, encephalitis
Severe metabolic acidosis
What can dialysis do
What can dialysis not do
Remove waste products, extra fluid => reverse uremia, hypervolemia
Maintain electrolyte, pH balance => address hyperkalemia, acidosis
No changes in hormones, must be managed separately
- EPO
- Vitamin D
Describe hemodialysis
- types of entry point
- pros and cons
Hemodialysis (attends for 3 4hour sessions per week)
- hospital, satellite unit, home
- heparinised system
- countercurrent dialysis and filtration
- air trap prevents air embolism
AV fistula - RC/BC/BB
- 1-2month maturation
- flow rate can vary with elasticity of vessel
- risk of blows, stenoses, thromboses
Graft - plastic tube connects artery and vein (DM affects vessels)
- no maturation
- risk of blows, stenoses, thromboses, infection
Central line - IJV
- plastic tube limits flow rate
- high infection risk
Describe peritoneal dialysis
- how is it done
- pros and cons
Peritoneal (continuous ambulatory, automated)
- home based, better QOL
- needs residual kidney function, ability to lift dialysate bags
- compliance hard to monitor
Catheter (lateral right to umbilicus)
- dialysate => peritoneum from a height
- peritoneal membrane = semi permeable membrane
- waste => bag at lower height when saturated
Complications of
- hemodialysis
- peritoneal dialysis
Hypotension, anuria => loss of too much fluid
Regular access to blood compartments => sepsis
Heparinised system => bleeds
Stenoses => clots
Dialyser reaction => inflammation
Air pumped into circuit => air embolus
Peritonitis => scars membrane
Leaks => pleural effusion, hydrocele
Membrane may not be suitable for complete toxin clearance
Pros and cons of transplant vs dialysis
Transplant - Gold standard
:) QOL
:( immunosuppresants for life
:( infection, malignancy risk
Dialysis \:) no shortages \:) no need for immunosuppresants \:( limit salt and protein \:( time consuming, exhausting
Donor types and success rates
Living => most successful
Brain/circulatory death => similar rates
Expanded criteria => may not be in best cond
ABO compatibility
-criteria that must be met to reduce hyperacute sensitivities
ABO Ag on donor
Recipient must not have ABO AB
O => universal donors
AB => universal recipients
HLA compatibility
-criteria that must be met to reduce sensitivites
HLA C6
-order of important DR, B, A
- Determine HLA type of patient and donor
- ideally, you want all 6 AG pairs to match (zero mismatch)
2. Patient HLA AB testing May be found due to -blood product use -pregnancy -past transplant use
If HLA AB found => find a donor without the complementary AG
The significance of cold ischemia time
Ischemia triggers innate immune system => increased rejection risk
Immunosuppresion
- induction
- maintenance
Induction - risk of rejection highest in 1st 3 months
-basiliximab
-thymoglobulin
Given around time of operation
Maintenance - taper down
-tacrolimus, mycomofetil, CS
Aim to balance SE against rejection due to SE
Complications post transplant
Hyperacute rejection - ABO, HLA mismatch, must remove organ
Acute rejection - T cell mediated rejection but medically managed
Chronic - vascular issues => kidney ischemia
High malignancy risk Infection risk -more opportunistic, common infections -fewer symptoms -REFER TO TRANSPLANT UNIT IF FEBRILE -PROMPT TREATMENT NEEDED, PATIENTS CAN DETERIORATE QUICKLY
