Dialysis and Renal Transplantation Flashcards
what is the purpose of dialysis
removes toxins
- urea
- potassium
- sodium
infusion of bicarbonate
how much dialysis does a patient need a week
4 hours
3 days a week
what are the restrictions put on patients on dialysis
Fluid
If anuric 1litre per day (including food based fluid)
Salt
Low salt diet to reduce thirst and help with fluid balance
Potassium
Low potassium diet.
Phosphate
Low phosphate diet
Phosphate binders with meals (6-12 pills per day)
what is the gold standard for dialysis access
fistula
what is a fistula
Joins an artery and a vein to make an enlarged thick walled vein called an Areteriovenous Fistula
what are the pros of a fistula
Good blood flow
Unlikely to cause infection
what are the cons of fistulas
Requires surgery
Requires maturation of about 6 weeks before can be used
Can limit blood flow to distal arm “steal”
Can block
what can be used instead of a fistula and what is it
Tunneled Venous Catheter
A catheter inserted into a large vein- Jugular, subclavian or femoral
what are pros of Tunnelled Venous Catheter
Easy to insert (usually)
Can be used immediately
what are the cons of tunnelled venous catheter
High risk of infection
Can cause damage to veins making placing replacements difficult
Become blocked
what can happen is a tunnelled venous catheter becomes infected
Endocarditis
Discitis
Death
Ix for tunnelled venous catheter infection
Blood Cultures
FBC and CRP
Exit site swab
Tx for tunnelled venous catheter infection
Antibiotics
- Vancomycin
Line removal or exchange
what are possible complications of dialysis
Fluid overload
Blood leaks
Loss of vascular access
Hypokalaemia and cardiac arrest
how does peritoneal dialysis work
Solute removal by diffusion of solutes across the peritoneal membrane.
Water removal by osmosis (water moving to equalise a concentration gradient) driven by high glucose concentration in dialysate fluid.
what are the two types of peritoneal dialysis
CAPD - Continous peritoneal dialysis
APD - automated peritoneal dialysis
what are possible complications in peritoneal dialysis
infection
- peritonitis or exit site infection
membrane failure
hernias
what bugs can cause infection in peritoneal dialysis
Staphylococci Streptococci Diptheroids E. Coli Klebseilla
Tx for peritoneal dialysis infection
Culture PD Fluid
Intraperitoneal Antibiotics
what happens in membrane failure
Inability to remove enough water so become fluid overloaded
Requires switch to Haemodialysis
what causes hernias in peritoneal dialysis
Increased intraabdominal pressure
Requires hernia repair and smaller fill volumes
what are metabolic complications seen in ESKD
Bone Mineral Metabolism
Phosphate retention
Low 1-25 Vit D
Hypocalcaemia
Raised PTH»_space; takes calcium away from the bones. Osteomalacia
what are metabolic complications seen in ESKD
Anaemia
Epo deficiency
Iron deficiency
other complications seen in ESKD
Sodium and water retention
Accelerated CV disease
what are the two ways to decide when to start dialysis
start based on bloods
start based on symptoms
what is the criteria for starting dialysis based on bloods
Resistant Hyperkalaemia
GFR 45
Unresponsive acidosis
what is the criteria for starting dialysis based on symptoms
Fatigue Itch Unresponsive fluid overload Nausea Vomiting Loss of appetite
what blood group is compatible for all blood groups of recipients
O
what are HLA and what do they do
cell surface proteins expressed on cells
activate the immune system
what are the 3 important types of HLA in transplant
HLA A
HLA B
HLA DR
why is HLA important
Donor Specific HLA Antibodies (Ab)
- A patient may have been exposed to a HLA Ag previously and formed Ab to this.
» This leads to rejection
what are the different forms of transplant rejection
Hyperacute
Acute
Chronic
what happens in hyper acute rejection
Due to +ve Xmatch (preformed antibodies to the Tx)
Unsalvageable
Remove kidney
what happens in acute rejection
Usually early
T cell or B cell mediated response
Can be treated with increased immunosupression
what happens in chronic rejection
Immunological and vascular deterioration of the Tx
what are Calcineurin Inhibitors
immune suppressors
how do Calcineurin Inhibitors work
Act by inhibiting activation of T helper cells
Reduce NK cells activation
Reduce Cytotoxic T cell activation
Decrease cytokine release so prevent B cell proliferation and antibody production
side effects of Calcineurin Inhibitors
Renal Dysfunction,
Hypertension,
Diabetes,
Tremors
how do Azathioprine and Mycophenolate work
Antimetabolites by blocking purine synthesis
Leads to suppression of proliferation of lymphocytes and B cells
what are side effects of azathioprine
Leucopaenia,
Anaemia,
GI side effects
what should never be given along side azathioprine
Allopurinol
how do steroids work
Act non selectively to suppress activity of T cells and proliferation of B cells.
what are indicates for suitability for transplantation
Patient should have reasonable life expectancy ( >5 years)
Well enough for an operation
contraindications for surgery
Malignancy - current or previous within in 2 years
Untreated TB Severe IHD Severe airway disease Acute vasculitis Severe PVD
what is the surgery for renal transplant
Extraperitoneal procedure
- Stent inserted between ureter and bladder
what are possible surgical complications
Bleeding (arterial or venous) Arterial Stenosis / Thrombosis Venous stenosis / Thrombosis Ureteric Stricture and hydronephrosis Wound infection
what drugs can cause a graft to be lost
Cyclosporine/ Tacrolimus toxicity
