Dialysis Flashcards
What are the functions of the kidneys?
Excretion of nitrogenous waste products
Maintenance of acid and electrolyte balance
Control of blood pressure
Activation of vitamin D
Production of erythropoietin
Drug metabolism and disposal
What is end stage renal disease?
Irreversible damage to a person’s kidneys so severely affecting their ability to remove or adjust blood wastes that, to maintain, life, he or she must have either dialysis, or a kidney transplant
What are the clinical features of advanced chronic renal failure (CRF)?
Until the GFR decrlined to 30ml/min the patient may be asymptomatic
The syndrome of advanced CRF is called uraemia
Uraemic symptoms can involve almost every organ system but the earliest and cardinal symptom is malaise and fatigue
What are some of the signs and symptoms or Uraemia?
Progressive weakness and easy fatigue,
Loss of appetite due to nausea and vomiting,
Muscle atrophy,
Tremors,
Abnormal mental function,
Frequent shallow respiration and metabolic acidosis.
What are the types of renal replacement therapy?
Haemodialysis
Peritoneal dialysis
Renal transplant
What are the types of peritoneal dialysis?
Continuous ambulatory peritoneal dialysis (CAPD)
Intermittent peritoneal dialysis (IPD)
What is dialysis?
Process whereby the solute composition of a solution, A, is altered by exposing solution A to a second solution, B, through a semipermeable membrane
What are the 2 basic principles of dialysis?
Diffusion
-Solutes filtered out
Ultrafiltration
-Fluids will follow solutes
What are the pre-requisites for dialysis?
Semipermeable membrane (artificial kidney in haemodialysis or peritoneal membrane)
Adequate blood exposure to the membrane (extracorporeal blood in haemodialysis, mesenteric circulation in PD)
Anticoagulation in haemodialysis
Dialysis access (vascular in haemodialysis, peritoneal in PD)
Give some examples of what is contained in the Dialysate
Freely permeable:
- Na+
- K+
- Ca2+
- HCO3-
Moves into dialysate from blood:
- Creatinine
- Urea
What are the indications for commencing dialysis in ESRD?
Advanced uraemia, usually GFR 10ml/min
Severe acidosis (bicarbonate 6mmol/l)
Fluid and salt retention not controlled with diuretics
Nephrologist’s clinical judgment is important
What should the dietary intake be for a dialysis patient?
Protein = 1.2-1.4 g/kg/24hrs
Calories 35-40 kcal/kg/24hrs
Vitamins: supplement water soluble vits
Restriction of dietary intake of potassium and salt
Restriction of dietary phosphate and use of phosphate binders
What is the fluid balance in haemodialysis?
Usually restricted to 500-800 ml/24hrs intake allowed = urine output + insensible loss
What is the fluid balance in peritoneal dialysis?
Usually more liberal intake than haemodialysis as continuous untrafiltration is often achieved
What drugs area dialysis patients usually prescribed?
Erythropoietin stimulating agent
One alpha vit-D or calcitriol
Phosphate binders with meals
Iron supplements
Water soluble vitamins
?antihypertensives
?lipid lowering drugs
