Renal Replacement Therapy

Question 1

What are the AEIOU indications for RRT?

Answer 1

A - acid/base disorder
E - electrolyte imbalance
I - intoxication due to poison ingestion
O - overload of fluid
U - uremia

Question 2

A general rule for initiation of HD is a BUN > ______ or SCr > ______.

Answer 2

100, 10

Question 3

What are two methods for maintaining vascular access in HD patients?

Answer 3

AV graft, AV fistula

Question 4

What are advantages and disadvantages of AV grafts?

Answer 4

• do not take as long as fistulas to mature (2-3 weeks vs. 1-2 months)
• synthetic material –> have to worry about rejection
• higher rate of infections, clots

Question 5

What are advantages and disadvantages of AV fistulas?

Answer 5

• long survival (up to 20 years)
• fewer complications compared to grafts
• take 2-3 months to mature
• can be a problem in diabetic patients with peripheral vascular disease (structure already compromised)

Question 6

What kinds of substances are not removed by dialysis?

Answer 6

(1) high volume of distribution
(2) high protein binding
(3) high lipid solubility
(4) hig molecular weight

Question 7

What is Kt/V? What is it used to gauge?

Answer 7

The Kt/V is a measure of the effectiveness of a dialysis session. K is the clearance of urea, t is the time spent on the machine, V is the volume of distribution of urea.

Question 8

What is a good value for Kt/V, and how can we change it if the value is not high enough?

Answer 8

A good value is 1.4 or more. If this value is not reached, the only variable that can be changed is t, so we would keep the patient on the dialysis machine longer.

Question 9

What is the URR, and what value would we like to see here after a dialysis session?

Answer 9

urea reduction ratio: a measure of how much BUN decreased during a dialysis session

We like to see 70% or more clearance.

Question 10

What are the four types of peritoneal dialysis (PD)?

Answer 10

continuous ambulatory
continuous cyclic
tidal
nocturnal intermittent

Question 11

Describe each of the four kinds of PD.

Answer 11

continuous ambulatory-dialysate drained and replaced at regular intervals throughout the day

continuous cyclic-dialysate not changed during the day, but patient sleeps hooked up to a machine that infuses and drains fluid throughout the night

nocturnal intermittent-no fluid present during the day, machine rapidly infuses and drains fluid through the night with no long cycles

tidal-no fluid during the day, but at night patient is infused to a certain tidal volume and cyclically infused (most expensive)

Question 12

Why are both long and short cycles beneficial for patients receiving peritoneal dialysis?

Answer 12

With peritoneal dialysis, the longer the cycle, the more large molecules you will remove. Smaller molecules are removed faster, but after a certain point the solution becomes saturated and no more will be removed before new fluid is introduced.

Question 13

What is a common complication associated with peritoneal dialysis?

Answer 13

peritonitis (infection of the peritoneal membrane)

Question 14

What are some symptoms of peritonitis?

Answer 14

(1) cloudy effluent (does not pass the “newspaper” test
(2) N/V
(3) abd px adn tenderness
(4) fever
(5) chills

Question 15

Which organism would likely be cultured if peritonitis was suspected?

Answer 15

staph epidermidis, but some G- organisms are causative

Question 16

Empiric therapy for peritonitis covers a broad spectrum of both _______ and ________ organisms.

Answer 16

G+ and G-

Question 17

By what route are antibiotics administered in patients with peritonitis from PD complications? For what reasons?

Answer 17

intraperitoneal

Patients receiving PD often have poor vascular access, so the IV route is not preferred. N/V symptoms eliminate oral route. Also, organisms are usually localized to the first few layers of the mesothelium, so local administration is generally good enough to kill a majority of the bacteria.

Question 18

Which forms of CRRT are primarily used for acute renal failure?

Answer 18

continuous arteriovenous hemofiltration (CAVH)
continuous venovenous hemofiltration (CVVH)
continuous venovenous hemodialysis (CVVHD)
continuos venovenous hemodiafiltration (CVVHDF)