Renal replacement therapy and transplantation

Renal replacement therapy has a vital role in the treatment of

• ACUTE (AKI: acute kidney injury)
• CHRONIC (end-stage renal disease)

Most patients with chronic kidney disease stage 4-5 (estimated GFR <30ml/min/1.72 m^2) or with CKD stage 3 and rapidly deteriorating renal function should be referred for assessment by nephrologist.

Should be referred at least a year in advance

Three ways to deal with it

• Conservative care and symptom control
• Dialysis
• Renal transplant

Conservative care

• Erythropoietin
• Vitamin D analogues
• Dietary control
• Antipruritics
• Antiemetics
• STILL need MDT
• Patients are more comfortable and more likely to die at home

Dialysis

• Malnourished without this
• Peritoneal or haemodialysis
• Good for young, bad for old

• In AKI, if:
• Uraemia (pericarditis, gastritis, hypothermia, fits or encephalopathy)
• Pulmonary oedema
• Severe hyperkalaemia
• Hypo and hypernatraemia
• pH very acidic (below 7.0)
• Severe renal failure urea greater than 30mmol/L and creatinine greater than 500micromol/L
• Toxicity with drugs that can be dialysed

• Haemodialysis complications
• Access-related: local infection, endocarditis, osteomyelitis, creation of stenosis, thrombosis or aneurysm
• Hypotension (common), cardiac arrhythmias, air embolism
• Nausea and vomiting, headache, and cramps
• Fever: Infected central lines
• Dialyser reactions: anaphylactic reaction to sterilising agents
• Heparin-induced thrombocytopenia, haemolysis
• Disequilibrium syndrome: restlessness, headache, tremors, fits, and coma
• Depression

• Peritoneal dialysis contraindications and complications 

• Contraindications
• Intra-abdominal adhesions and abdominal wall stoma
• Obesity, intestinal disease, respiratory disease and hernias are relative contra-indications

• Complications of peritoneal dialysis
• Peritonitis
• Sclerosing peritonitis
• Catheter problems: infections, blockage, kinking, leaks, or slow drainage
• Constipation, fluid retension, hyperglycaemia, weight gain
• Hernias (incisional, inguinal umbilical)
• Back pain
• Malnutrition 
• Depression

Transplantation

• Best long-term outcome for patients with end-stage renal disease
• Cadaveric or living
• All patients with end-stage renal disease should be considered for a transplant
• Patients followed up
• Cancer
• Drug toxicity
• Cardiovascular disease

Complications of transplantation and subsequent immunosuppression

• Postoperative problems - e.g. deep vein thrombosis, pulmonary embolism and pneumonia
• Opportunistic infections: viral (particularly herpes simplex in the first four weeks and then cytomegalovirus (CMV) later), fungal and bacterial
• Malignancies (especially lymphomas and skin cancers)
• Drug toxicity, bone marrow suppression
• Recurrence of the original disease in the transplant
• Urinary tract obstruction
• Cardiovascular disease, hypertension, dyslipidaemia
• Graft rejection:
• Hyperacute: occurs within minutes of insertion. Is now rare due to more accurate cross-matching. Requires removal of graft.
• Accelerated: aggressive mainly T-cell mediated crisis can occur within a few days in patients previously sensitised. Presents with fever, swollen transplanted kidney and rapidly increasing serum creatinine. Can be salvaged with high-dose steroids plus antilymphocyte antibiotics but long-term survival is affected
• Acute cellular: occurs in around 25% of patients usually in 1-3 weeks but can occur up to 12 weeks. Clinical signs are fluid retention, rising blood pressure and rapid increase in creatinine. Treatment is with intravenous steroids after diagnosis by biopsy. Latest induction regimens can reduce incidence of acute rejection to 10%
• Chronic: presents with a gradual rise in serum creatinine and proteinuria, resistant hypertension. Graft biopsy shows vascular changes, fibrosis, and tubular atrophy. It is not responsive to increasing immunosuppression therapy

Prognosis

• The outcome of renal transplantation has steadily improved. 1 year and 10 year graft survival rates are 89% and 67% for adult kidneys from 'brain death donors' and 96% and 78% for kidneys from live donors. Survival of the transplant recipient at 10 year for cadaveric and live donor transplants in 71% and 89% respectively
• Acute rejection and early graft loss are becoming increasing less common
• Cadaveric donor renal transplantation, more human leukocyte antigen (HLA) mismatches, increasing donor age, cold ischaemia time greater than 24 hours, and a history of diabetic nephropathy all increase the risk of graft failure, return to dialysis and death