Renal replacement therapy 1 Flashcards
What 2 functions of the kidney does dialysis not replace?
erythropoietin production
activation of vitamin D
Define ESRD
irreversible damage to the kidneys severely affecting the ability to remove or adjust blood waste that to maintain life the patient must have dialysis or a transplant
What is the syndrome of advanced CKD called?symptoms of this
Uraemia
earliest and cardinal sign is malaise and fatigue
RRT definition
the means by which life is sustained in patients suffering from ESRD
When is RRT usually indicated?
GFR<10mls/min but is variable
4 types of RRT
renal transplant
haemodialysis - satellite or hospital
Peritoneal dialysis - CAPD or IPD
conservative management - symptoms of urea
Define dialysis
A process which solute composition of solution A is altered by exposing it to solution B over a semi permeable membrane
2 principles of dialysis
diffusion
ultrafiltration - remove water
4 pre requisites for dialysis
semi permeable membrane - artificial kidney or peritoneal membrane
adequate blood exposure - extra corpeal or mesenteric
dialysis access - vascular or peritoneal
anti coagulation for haemodialysis
What type of dialysis requires anticoagulation?
hamodialysis
Types of permanent dialysis access
AV fistula or AV prosthetic graft
Types of temporary dialysis access
tunnelled/temporary venous catheter
What is a dialysate?
fluid we produce for the other side of the concentration gradient which we expose to the blood
What are the main electrolyte shifts in dialysis?
bicarbonate into blood (for metabolic acidosis)
remove urea and creatinine
How do the blood and dialysate move in terms of eachother and why?
opposite directions
maintain and optimise concentration gradient
Fluid restrictions in dialysis - how are these calculated?
interdialytic weight gain
indicated by residual urine output
Dietary restrictions in dialysis
phosphate, potassium and sodium
CV problems - HD complications
hypotension and cramps
arrhythmias
myocardial stunning and fibrosis
Coagulation problems with HD
clotting of vascular access
heparin related problem eg hair loss, thrombocytopenia
Other HD problems
allergic reactions to dialyser and tubing
Explain the basics of PD
a balanced dialysis solution is instilled into the peritoneal cavity through a catheter using the peritoneal membrane and fluid drained out and fresh fluid instilled
What is the most common osmotic agent for ultrafiltration of fluid in PD?
glucose
What is important in deciding between CAPD or APD?
peritoneal membrane characteristics and personal choice
PD complications
exit site infection
PD peritonitis - gram +ve = skin commensal
gram -ve = gut commensal and if mixed perhaps think a perforation
tunnel infection
ultrafiltration failure
technical eg tube, hernia
4 indications for dialysis in ESRD
advanced uraemia GFR<5-10ml/min
severe acidosis - bicarb<10mmol/min
Treatment resistant hyperkalaemia
treatment resistant fluid overload
Fluid restriction for HD and PD
HD : 500-800ml per day
PD - more flexible
What drugs may be given along dialysis?
Erythropoietin injections and IV iron activated vit D - calcitriol phosphate binders with meals eg CaCo3 heparin replace water soluble vitamins anti hypertensives?
