Slide 1

Dr Dana Ahmed Sharif Slide 2 Median life expectancy on RRT by age group Median life expectancy on RRT by age group incident patient starting RRT from 2000-2007 incident of diabetic patient starting RRT from 2000-2007 UK renal registry data, annual report 2011 Slide 3 When to start dialysis? 1- 50 years old male with GFR 13, K 5.4, mild leg oedema otherwise well 2- 55 years old female with GFR 12, K: 5.2 with nausea, itching and anorexia 3- 48 years old female with GFR 9, K: 5.0 good urine output, BP 155/90mmHg 4- 52 years old male with GFR 8, K: 5.0 with tiredness Slide 4 When to start dialysis? GFR < 15ml/min with uraemic symptoms GFR < 10ml/min whether symptomatic or not Refractory hyperkalaemia, acidosis, pulmonary oedema, pericarditis, encephalopathy and neuropathy ( all need urgent dialysis) There is no clear evidence that an early start to dialysis confers a survival benefit* Pre-emptive transplant is the treatment of choice of ESRF. Consider when GFR < 15ml/min *RCT of Early versus late initiation of dialysis, N Engl J Med 2010; 363:609-619, August 12/ 2010 Slide 5 Principles of dialysis Salt Water Electrolytes Acidosis Toxins Slide 6 Haemodialysis Largely hospital based Efficient Requires access to circulation Limited by staff and space Slide 7 Haemodialysis Artificial membrane used for exchange Extracorporeal circuit Direct access to blood Slide 8 Haemodialysis access Tunnelled dialysis line A-V fistula Slide 9 Haemodialysis 1- Diffusion: Diffusion of solutes between solutions across a semipermeable membrane down a concentration gradient Slide 10 Principles of dialysis Slide 11 Determining factors: -Concentration gradient - Size + protein binding of molecule removed - Permeability + surface area of membrane Slide 12 Haemodialysis 2- Ultrafiltration: - Water can be driven through the membrane by hydrostatic force - By varying the trans-membrane pressure (TMP) the amount of water removed can be controlled Slide 13 Haemofiltration Convection - Flow of water + dissolved solutes (convection) down a pressure gradient caused by hydrostatic or osmotic forces - Rate of filtration depends on pressure gradient Slide 14 Haemofiltration Slide 15 Basic principles Haemodialysis Solute removal by diffusion of substances between blood + dialysate Fluid removed by filtration (driven by pressure gradient across membrane) Haemofiltration Fluid removal by filtration Solute removal by convection of substances in filtrate Slide 16 Haemodialysis(HD) Haemofiltration(HF) Slide 17 Slide 18 Haemodiafiltration Combines both HD and HF Set for HD with high TMP Both dialysate and fluid replacement required Slide 19 Haemodialysis- complications Access complications: - Thrombosis - Infection - Lack of access Dialysis complication: - Reactions (hypersensitivity, inflammation) - Hypotension - Haemorrhage - Air embolism - Cardiac arrhythmias Slide 20 Peritoneal Dialysis Slide 21 CAPD: principles Slide 22 Peritoneal dialysis Partly relies on residual renal function Home based Ambulant Flexible Continuous / intermittent Slide 23 Peritoneal dialysis- CAPD 4 x 2L exchanges a day Each exchange takes ~ - 1 hour Complications - Peritonitis - Loss of membrane function Slide 24 Automated Peritoneal Dialysis Night time exchanges only Convenient for people in employment Slide 25 Peritoneal dialysis Advantages: - continuous, independence - home based, flexible Disadvantages: - patient competence - peritonitis - membrane failure - ultrafiltration failure - catheter exit site infection - sclerosing peritonitis Slide 26 Transplantation Slide 27 Compatibility - Blood group - HLA tissue type - Antibodies Slide 28 Blood group ABO antigens are expressed on endothelial cells in the kidney Naturally occurring anti-blood group antibodies develop at 6 months of age, possibly in response to bacterial carbohydrate antigens The same role apply for transplantation and blood transfusions (ie blood group O are universal donor and AB are universal recipient) ABO incompatible transplant are generally avoided Slide 29 Tissue typing Class I : HLA -A and B Class II: HLA DR So HLA identical donors have 0,0,0 mismatch(MM) Whereas those pairs which share 1 HLA- A, 1 HLA B and 1 HLA DR have 1,1,1 MM Slide 30 Benefits of well matched graft Lower acute rejection rate Better long term graft survival Fewer subsequent anti HLA antibodies Lower incidence of delayed graft function Slide 31 Anti- HLA Antibodies (sensitization) Previous mismatched organ transplant Mismatched paternal HLA antigen in Pregnancy Blood transfusion Slide 32 Donor type Live donor - related - non related Cadaveric donor - Heart beating ( brain death) - Non heart beating Slide 33 Medication post transplant Immunosuppressive drugs: - Calcineurin inhibitors (Ciclosporin, Tacrolimus) - Antiproliferative ( Mycofenolate mofetil MMF, azathioprine) - mTOR inhibitors (sirolimus, Everolimus) - Steroids Slide 34 Complications Infections - Bacterial - Fungal - Viral EBV, CMV - atypical Cancer - Skin - Lymphomas PTLD ( post transplant lympho-proliferative disorder) - Solid tumours Metabolic - Diabetes - Hypertension - Osteoporosis Slide 35 Contraindication to renal transplant Absolute: 1- Active malignancy, a period of 2 years of complete remission recommended for most tumors 2- Active vasculitis or recent anti-GBM disease 3- Severe heart failure 4- Severe occlusive aorto-iliac vascular disease Relative: 1- Age: not routinely offered to 75 yrs 2- High risk of disease recurrence in the transplant kidney 3- Disease of the lower urinary tract such as bladder dysfunction 4- Significant comorbidity