Peritoneal Dialysis

Question 1

Dialysis

Answer 1

Movement of fluid/molecules across a semipermeable membrane from one compartment to another
Used to correct fluid/electrolyte imbalances and to remove waste products in renal failure
Treat drug overdoses

Question 2

Dialysate

Answer 2

Dialysis solution

Question 3

Dialysis is done when…

Answer 3

Patient's uremia can no longer be adequately managed conservatively
When GFR (or creatinine clearance) is less than 15 mL/min

Question 4

Diffusion

Answer 4

Movement of solutes from an area of greater concentration to an area of lesser concentration
In kidney failure, urea, creatinine, uric acid, K and phos move from blood to dialysate

Question 5

Osmosis

Answer 5

Movement of fluid from an area of lesser concentration of solutes to an area of greater concentration of solutes
Glucose added to dialysate and creates osmotic gradient across membrane, pulling excess fluid from blood

Question 6

Ultrafiltration

Answer 6

Removes water and fluid through an osmotic gradient
Fluid is removed by increasing osmolality of dialysate with addition of glucose
Gradient is created by increasing pressure in blood compartment (pos pressure) or decreasing pressure in dialysate compartment (neg pressure)

Question 7

Peritoneal dialysis

Answer 7

Access is obtained by inserting a catheter through the anterior abdominal wall
Technique for catheter placement varies
Usually done via surgery

Question 8

3 Phases of PD Cycle

Answer 8

Inflow
Dwell
Drain

Called an exchange

It is called an exchange

Question 9

Inflow

Answer 9

Prescribed amount of solution is infused through catheter over 10 minutes.
Flow rate mate be decreased if patient has pain
After solution has been infused, clamp is closed before air enters the tubing.

Question 10

Dwell

Answer 10

Diffusion and osmosis occurs between patient’s blood and peritoneal cavity. Duration of phase ranges from about 20-30 minutes to 8 hours depending on method (APD: automatic peritoneal dialysis and CAPD: continuous ambulatory peritoneal dialysis)

Question 11

Drain

Answer 11

15-30 minutes and may be facilitated by gently massaging abdomen or changing position

Question 12

Dialysis solutions

Answer 12

Available in 1- 2- or 3L plastic bags w/ glucose concentrations of 1.5%, 2.5%, and 4.25%
Electrolyte composition similar to that of plasma
Solution warmed to body temp, warmed slowly, no microwaving
Exchange dependent on body weight and BP