NURS 4301 Exam 3 Principles Of Dialysis Learning
Objectives Questions And Answers
Identify indications for dialysis - ANSWER corrects fluid and electrolyte imbalances and
removes waste products in kidney failure; drug overdoses; GFR <15 in CKD
Peritoneal dialysis (PD) - ANSWER peritoneal membrane acts as a semipermeable
membrane; dialysate is infused into the peritoneal (abdominal) cavity, allowed to dwell
as exchange occurs internally, then drained
Hemodialysis (HD) - ANSWER an artificial membrane (usually made of cellulose-based
or synthetic materials) is used as the semi permeable membrane and is in contact with
the patient's blood; exchange occurs in machine outside of body
Explain how the principle of osmosis is involved in dialysis - ANSWER movement of fluid
from an area of lesser concentration to an area of greater concentration of solutes;
glucose is added to dialysate → creates an osmotic gradient across the membrane →
pulls excess fluid from the blood
Explain how the principle of diffusion is involved in dialysis - ANSWER movement of
solutes from an area of greater concentration to an area of lesser concentration; urea,
creatinine, uric acid, and electrolytes (potassium, phosphate) move from the blood to
the dialysate with the net effect of lowering their concentration in the blood
Explain how the principle of ultrafiltration is involved in dialysis - ANSWER water and
fluid removal that results when there is an osmotic gradient or pressure gradient across
the membrane; PD: excess fluid is removed by increasing the osmolality of the dialysate
(osmotic gradient) with the addition of glucose; HD: the gradient is created by
increasing pressure in the blood compartment (positive pressure) or decreasing
pressure in the dialysate compartment (negative pressure) → ECF moves into the
dialysate due to the pressure gradient
Discuss the advantages of peritoneal dialysis - ANSWER PD patients live longer; more
mobility and flexibility; no machine required; may have fewer fluid and diet restrictions;
Objectives Questions And Answers
Identify indications for dialysis - ANSWER corrects fluid and electrolyte imbalances and
removes waste products in kidney failure; drug overdoses; GFR <15 in CKD
Peritoneal dialysis (PD) - ANSWER peritoneal membrane acts as a semipermeable
membrane; dialysate is infused into the peritoneal (abdominal) cavity, allowed to dwell
as exchange occurs internally, then drained
Hemodialysis (HD) - ANSWER an artificial membrane (usually made of cellulose-based
or synthetic materials) is used as the semi permeable membrane and is in contact with
the patient's blood; exchange occurs in machine outside of body
Explain how the principle of osmosis is involved in dialysis - ANSWER movement of fluid
from an area of lesser concentration to an area of greater concentration of solutes;
glucose is added to dialysate → creates an osmotic gradient across the membrane →
pulls excess fluid from the blood
Explain how the principle of diffusion is involved in dialysis - ANSWER movement of
solutes from an area of greater concentration to an area of lesser concentration; urea,
creatinine, uric acid, and electrolytes (potassium, phosphate) move from the blood to
the dialysate with the net effect of lowering their concentration in the blood
Explain how the principle of ultrafiltration is involved in dialysis - ANSWER water and
fluid removal that results when there is an osmotic gradient or pressure gradient across
the membrane; PD: excess fluid is removed by increasing the osmolality of the dialysate
(osmotic gradient) with the addition of glucose; HD: the gradient is created by
increasing pressure in the blood compartment (positive pressure) or decreasing
pressure in the dialysate compartment (negative pressure) → ECF moves into the
dialysate due to the pressure gradient
Discuss the advantages of peritoneal dialysis - ANSWER PD patients live longer; more
mobility and flexibility; no machine required; may have fewer fluid and diet restrictions;
