RRT Flashcards
When should dialysis be discussed?
less than 20ml/min
When are patients referred to vascular surgeons for AVF?
15ml/min
When can AVF and peritoneal catheter be used?
AVF: 6 weeks
Peritoneal catheter: 1-2 weeks
When can patients be listed for transplant?
When within 6 months of dialysis
Dialysis allows removal of what toxins that build up in CKD?
Urea
Potassium
Sodium
Dialysis also allows infusion of what?
Bicarbonate (if acidotic)
How does dialysis work?
Diffusion
How does dialysis get rid of water?
Convection (water sucked out across membrane)
Filtration
GFR in dialysis patients
10-12
Too quick correction of metabolic issues =
Disequilibirum syndrome
Cerebral oedema
Seizures
What restrictions does dialysis put on patient?
Fluid restriction 1L/day Na restriction 3-4g/day Glucose restriction K restriction (low bananas/chocolate/potatoes) Phosphate restriction (phosphate binders with meals)
Pros of fistula
Good blood flow
Unlikely to cause infection
Cons of fistula
Surgery
6 weeks to mature
Poor circulation in hand
Can block/thrombose
Tunneled venous catheter
Catheter into large vein (jugular/subclavian/femoral/hepatic)
Pros of TVC
Easy to insert
Can be used immediately
Cons of TVC
High risk of infection
Damage to veins
Block
Treatment of TVC infection
Vancomycin
What can go wrong with HD?
Fluid overload Blood leaks Loss of vascular access Hypokalaemia (cardiac arrest) Intradialytic hypotension (removing large volumes)
Peritoneal dialysis
Solute removal by diffusion across peritoneal membrane
Water removal by osmosis driven by high glucose concentration in dialysate fluid
CAPD
Continual peritoneal dialysis
4 bag changes per day, 1/2 hour per exchange
APD
Automated peritoenal dialysis
1 bag stays in all day
Overnight machine drains for 9-10 hours
Can take on holiday
What can go wrong with PD?
Infection
Membrane failure = switch to HD
Hernia
Treatment for PD infection
Vancomycin and Gentamicin
Metabolic complications in ESKD
Bone metabolism (phosphate retention, low Vit D, hypocalcaemia because no Ca reabs, secondary hyperparathyroid = rickets)
Anaemia (epo/iron deificency)
Na and water retention
Accelerated CVD
When to start dialysis based on bloods
Resistant hyperkalaemia
GFR less than 5
Urea over 45
Unresponsive acidosis
When to start dialysis based on symptoms
Fatigue Itch N+V Oedema unresponsive Loss of appetite Malnourished
Cell surface receptors expressed on cells
HLA/MHC
3 HLA types important in transplant
HLA-A (class I) HLA-B (class I) HLA-DR (class II)
How can someone form HLA Abs?
Previous exposure to HLA Ag, e.g. blood transfusion, pregnancy, previous transplant
Abnormal infections in transplant patients
CMV BK virus (viral changes in kidney) Recurrent UTI Pneumocystis jirovecii = co-trimoxazole NMSC Post-transplant lymphoma (EBV)
How is rejection diagnosed?
Raised CK
Biopsy
Hyperacute rejection
Minutes
Due to preformed Abs (previous transfusion/transplant)
Vascular thrombosis
Unsalvageable = remove kidney
Acute rejection
Early
T or B cells
Stop taking pills = acute rejection
Increase immunosuppression
Chronic rejection
Immunological and vascular deterioration of transplant
Periods of immunosuppression
Induction
Consolidation
Maintenance
How do calcineurin inhibitors work?
Inhibit activation of T helper cells = reduce NK activation and cytotoxic T cell activation
Decrease cytokines = no B cells or Abs
Example of calcineurin inhibitor
Cyclosporin
Tacrolimus
Side effects of calcineurin inhibitor
Renal dysfunction HT Diabetes Tremor Drug interactions (cytochrom p450)
How do aza and mycophenolate work?
Block purine synthesis = suppresses lymphocytes and B cells
Side effects of aza and mycophenolate?
Leukopenia (low WCC), anaemia, GI side effects, careful in sun
How do steroids work?
Non-selectively to suppress T cells and B cells
Types of donor kidney
DBD
DCD
Live donor
Kidney/Pancreas dual transplant
DBD
Deceased brain dead - kidneys removed at same time as other organs, removed and put on ice
DCD
Deceased cardiac death
Only kidney and liver used
Used by local centre
Live donor
Usually family
Planned, well matched
Dual transplant
Islet cells and kidney for T1DM
Assessing patients for transplant
CV risk (ECG, echo, ETT, cholesterol) Virology (HBV, HCV, HIV, CMV, EBV) CXR (tumours) Bladder assessment Comorbidity
Absolute contraindications for transplant
Malignancy (last 2 years, 5 if breast/colorectal) Untreated TB/latent TB Severe IHD Severe airways disease Severe PVD Active vasculitis
How long is hospital stay for transplant?
7 days