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