Renal Replacement Therapy Flashcards
What are the functions of the kidneys?
Excretion of nitrogenous waste products
Maintenance of acid and electrolyte balance
Control of BP
Drug metabolism and disposal
Activation of Vitamin D
Production of erythropoietin
What is the definition of end stage renal disease (ESRD)?
Irreversible damage to kidneys so severely affecting their ability to remove or adjust blood wastes that, to maintain life, must have dialysis or kidney transplant
What are the clinical features of advanced CKD?
May be asymptomatic till stage 4 or 5
Syndrome of advanced CKD is called uraemia
Uraemic symptoms can involve every organ system but earliest symptoms are malaise and fatigue
What is renal replacement therapy?
Means by which life is sustained in patients suffering from ESRD
Usually indicated when eGFR is less than 10ml/min
What are the types of renal replacement therapy?
Renal transplant
Haemodialysis - home or hospital/ satellite
Peritoneal dialysis - CAPD and IPD
Conservative kidney management
What is dialysis?
Process whereby the solute composition of a solution, A, is altered by exposing solution A to a second solution, B, through semipermeable membrane
What are some pre-requisites for dialysis?
Semipermeable membrane - artificial kidney in haemodialysis or peritoneal membrane
Adequate blood exposure to membrane
Dialysis access - vascular for haemodialysis and peritoneal for PD
Anticoagulation in haemodialysis
Describe haemodialysis access
Permanent - arteriovenous fistula or AV prosthetic graft
Temporary - tunnelled venous catheter and temporary venous catheter
What are the restrictions for dialysis patients?
Fluid restriction - dictated by residual urine output and interdialytic weight gain
Dietary - potassium, sodium and phosphate
Describe peritoneal dialysis
A balanced dialysis is instilled into peritoneal cavity via a tunnelled, cuffed catheter using peritoneal mesothelium as dialysis membrane
After dwell time the fluid is drained out and fresh dialysate is instilled
What are the types of peritoneal dialysis?
Continuous ambulatory peritoneal dialysis (CAPD)
Automated peritoneal dialysis (APD)
Hybrid
Describe peritoneal dialysis fluids
Dialysate contains a balanced conc. of electrolytes
Glucose is most common osmotic agent for ultrafiltration of fluid
High transporter to low transporter - dwell times adjusted according to these characteristics
What are some complications of peritoneal dialysis?
Exit site infection
PD peritonitis
Ultrafiltration failure
Encapsulating peritoneal sclerosis
What are the indications for dialysis in ESRD?
Advanced uraemia (GFR 5-10ml/min)
Severe acidosis
Treatment resistant hyperkalaemia
Treatment resistant fluid overload
What is the fluid restriction for haemodialysis?
Usually restricted to 500-800ml/24 hrs intake allowed
What is the fluid restriction for peritoneal dialysis?
Usually more liberal intake as continuous ultrafiltration if often achieved
What are some dialysis related drugs?
Anaemia - erythropoietin injections and IV iron supplements
Renal bone disease - activated vitamin D and phosphate binders with meals
Heparin
Water soluble vitamins
What are some complications with haemodialysis?
CV problems - intra-dialytic hypotension + cramps and arrhythmias
Coagulation - clotting of vascular access and heparin related problems
Other - allergic reactions and catastrophic dialysis incidents
What are come complications of peritoneal dialysis?
Infection - exit site infection, tunnel infection and peritonitis
Mechanical - tube malfunction and abdominal wall hernia
Ultrafiltration problems
What are the limitation of dialysis?
Dialysis is a substitute for kidneys but is only a means of keeping patient alive
Have increased morbidity and mortality
Describe conservative kidney management
Supportive care - priority of symptomatic care, holistic multi-disciplinary approach and anticipatory care planning
What are the principles of dialysis?
Diffusion and ultrafiltration
What is involved in renal transplantation?
Transplanted kidney is placed into iliac fossa and anastomosed to the iliac vessels
Native kidneys usually remain in situ but size of kidney and infection can be an indication for removal of native
What is included in the process of kidney transplantation?
Liver donor nephrectomy
Preservation of donor kidney - cold storage solutions, minimise oedema, preserve integrity of tissues and buffer free radicals
Transplant
What are some transplant surgical complications?
Vascular complications - bleeding, arterial thrombosis, venous thrombosis and lymphocele
Ureteric - urine leak
Infections
What are the immunosuppressive agents used for kidney transplants?
Corticosteroids, calcineurin inhibitors, anti-proliferative, mTOR inhibitors, costimulatory signal blockers and depleting agents
What are some side effects of corticosteroids?
Hypertension, hyperglycaemia, infections, bone loss and GI bleeding
What are the side effects of tacrolimus?
Hyperglycaemia, AKI and tremor
What are the side effects of cyclosporin?
Hirsutism, hypertension, AKI and gout
What are the side effects of mycophenolate mofertil?
Cytopenia and GI upset
What are the side effects of sirolimus?
Lipidogenic, diabetogenic and pneumonia
What are the side effects of Belatacept?
Infections and malignancy
What are the side effects of anti-thymocyte globulin (ATG)?
Infections and post-transplantation lymphoproliferative disease (PTLD)
What is the immunosuppression protocols for kidney transplants?
Induction - Basiliximab
Maintenance - Tacrolimus + mycophenolate + steroids
Steroid free is possible
Others - CNI-free using Belatacept
What are the types of donors?
Deceased donors - donation after brain death or donation after cardiac death
Living donors - related donor and unrelated donor
What is included in the brain death criteria?
Coma, unresponsiveness to stimuli, apnoea off ventilator, absence of cephalic reflexes, body temp. above 34 degrees and absence of drug intoxication
What is part of the extended criteria (ECD)?
Donor aged above 60 years
Donor aged 50-59 + history of hypertension, death from cebro-vascular accident and terminal creatinine above 133umol/l
What are the types of living kidney donation?
Live related donor
Live unrelated donor - spousal or non-directed
Paired/ pooled
ABO incompatible/ HLA incompatible
Explain the risk of kidney donation
Similar patient survival to general population
Lower rate of ESRD
Compensatory increase in GFR of remaining kidney to 70%
Relatively short follow up time
Older age and high BMI associated with GFR under 60
What are some complications after renal transplantation?
Rejection - cell mediated or humoral
CV - underlying renal disease, CRF, hypertension, hyperlipidaemia, and PT diabetes
Infective
Malignancy - skin, lymphoma and solid cancers
What are the types of acute rejection of kidney transplant?
T cell mediated rejection - tubulointerstitial, arteritis/ endothelialitis, and arterial fibrinoid necrosis
Acute antibody mediated rejection - ATN-like, capillaries or glomerular inflammation and arterial inflammation
What is included in T cell mediated rejection?
Lymphocytic infiltrate
Tubulitis
Endarteritis
Endothelialitis
What is included in antibody mediated rejection?
Microvascular inflammation
Donor specific antibodies
Positive C4d
Describe cytomegalovirus and kidney transplant
Most important transplant related infection
High mortality and morbidity if left untreated
Recipient affected via transmission from donor tissue and reactivation of latent virus
What is included in Polymaviridae?
BK virus and JC virus
Murine polyoma virus and SV40
What are BK virus clinical manifestations in renal transplantation?
Ureteral stenosis
Interstitial nephritis
ESRF
What are some risk factors for BKAN?
Intensity of immunosuppression
Patient determinants - age, male, white, DM, negative KKV serostatus
Organ determinants
Viral determinants
What is the outcome and management for BKAN?
Allograft dysfunction and loss of graft in 45-80%
Treatment - reduce immunosuppression and antiviral therapy - cidofovir + IVIG and leflunomide
