Flashcards in Dialysis- Final Exam Deck (84)
Long-term kidneys problems have significant repercussions on other diseases such as what?
Removed total body water on the principle of hydrostatic pressure gradients
What is used to treat renal failure?
Dialysis; removal of diffusable solutes based on the principle of concentration gradient and solute drag established by dialysate solution
Describe the diffusion of molecules.
How do you control water?
Controlling transport of sodium
influence exerted by a flow of solvent through a membrane on the simultaneous movement of a solute through the membrane
Types of dialyzers
Describe the blood compartment of a coil dialyzer.
Blood compartment consisted of one or two long membrane tubes placed between support screen and wound around a plastic core
Why are coil dialyzers restricted in use?
Serious performance limitations; coil design did not produce uniform dialysate flow distribution across the membrane
Describe the setup of a parallel plate dialyzer.
Sheets of membrane are mounted on plastic support screens, and then stacked in multiple layers range from 2 or 20 or more.
What do parallel plate dialyzers allow?
Multiple parallel blood and dialysate flow channels (lower resistance to flow)
Major improvements in parallel plate dialyzer allow what (3)?
1. Thinner blood and dialysate channels with uniform dimensions
2. Minimal masking or blocking of membranes on the support
3. Minimal stretching or deformation of membranes across the supports
What dialyzer has the most effective design?
Hollow Fiber Dialyzer
Describe the design of the hollow fiber dialyzer.
Low-volume high efficiency with low resistance to flow. Fiber bundle are potted in polyurethane at each end of the fiber bundle in the tube sheet, which serves as the membrane support.
__________ machines offer tremendous flexibility in adjusting dialysis regimens.
What type of system do hemodialysis machines use?
Single pass system where the dialysate circulates through the dialyzer once and is then discarded
What 3 components do all dialysis systems require?
1. Dialysate Heater (to warm to body temp)
2. Dialysate pump/flow meter (regulate rate of delivery)
3. Sensors/alarms (pressure, temp, conductivity, air or blood leaks)
When dialyzing, patient blood is on one side and what type of solution is on the other side?
Hypotonic solution (dialysate)
What creates movement of molecules across membrane in hemodialysis?
Movement from hypertonic blood to hypotonic solution (dialysate)
What substances in the blood decrease in hemodialysis?
BUN, creatinine, electrolytes
HOw can fluid pass through semipermeable filter membrane in hemodialysis?
By applying suction on the far side of the membrane
What creates a transmembrane pressure gradient?
What happens when you use vacuum?; What is meant by convective transport or solvent drag?
Small solute molecules get dragged out through the membrane pores along with the water
The movement of solutes through the membrane ("convective flux") is calculatable
Almost all single-patient hemodialysis machines use a ______________, where the dialysate circulates through the dialyzer once and is then discarded.
What temperature should the dialysate be?
Body temp, 37
What is more effective: peritoneal dialysis or hemodialysis?
When is peritoneal dialysis effective?
Very labile cardiac states
Tx of choice in kids