Maintenance Dialysis Flashcards
Two types of dialysis
peritoneal dialysis
hemodialysis
- 3x a week, @ 3-4 hours
Indications for starting dialysis
hyperkalemia severe volume overload poorly responsive HTN uremic pericarditis, pleuritis uremic encephalopathy/nephropathy uremia causing bleeding
- even if they have less severe symptoms, you should still initiate if pt has appropriate access
- IDEALLY before life-threatening symptoms develop
If a pt does not have appropriate dialysis access, how do you initiate dialysis?
initiate with a vascular catheter
Specific GFR mandating dialysis?
No specific GFR
(though most pts w/ depressed GFR
Hemodialysis steps
blood is rapidly moved through extracorporeal circuit
Blood is removed by needle/catheter port → enters semi-permeable membrane → dialysate moves in counter-current fashion → solutes (urea) in blood move into dialysate(low [ ]) → blood is returned via separate needle/port
Preferred access for dialysis?
Arteriovenous fistula (AVF)
- anastamoses of artery to vein (mainly placed in arm)
- Lowest infxn rate
- Longest lifespan
- take time to mature (6-8 weeks)
Arteriovenouous GRAFTS
(not AVFs)
AVGs are synthetic grafts that are connected to artery and vein
- used more quickly w/ higher success rate
- fail quicker, higher risk of infxn
Between AVF and AVg, which has lower infxn rate? quicker?
AVF lowest infection rate
AVG higher success rate, quicker
dual lumen catheters have- higher infxn rate than AVF and AVG
Dual lumen catheters
a dialysis catheter is placed in internal jugular vein
- can be used immediately for dialysis
- higher infxn rate than AVF and AVG
- high rate of dysfxn
If pts have stage IV CKD, which is the preferred access?
AVFs
Is hemodialysis better at removing large or small molecules?
smaller
another downside to incenter hemodialysis, is that it removes large volumes of fluid during a 4 hour treatment
Most common HD bloodstream infxn?
Gram + Staph aureus
Coagulase negative Staphylococci
complications of Hemodialysis?
Hypotension
angina
MI
infxn
Very serious/rare: air emboli, anaphylaxis
Most common type of dialysis world wide?
peritoneal dialysis (not in the US though...) - hemodialysis is most common in US
Peritoneal dialysis
coiled catheter is placed in peritoneal cavity → tunneled through Subcutaneous portion of the abdominal wall to an exit site. → sterile, pre-packed dialysate (high dextrose) is infused into peritoneal cavity → blood moves from bloodstream to peritoneal cavity by osmosis → solutes move with the blood by convection → drain dialysate and ultrafiltered fluid → start new dialysate
- lower cost
