Renal Replacement Therapies

Question 1

5 Reasons to Dialyze Someone

Answer 1

A - Acidosis
E - Electrolytes (K+)
I - Intoxications (overdoses)
O - Fluid overload (too much water)
U - Urea

Question 2

Principles of RRT

Answer 2

• Forces diffusion to achieve equilibrium
• Ultrafiltrate convection: movement of particles dissolved in fluid
• Consists of blood, membrane, and efferent side

Question 3

Dialyzer Characteristics

Answer 3

• Membrane composition: polysulfone, polyacrylonitrile
• Size/surface area: high-efficacy, large surface area
• Filter pore size: conventional (standard), small molecules, =<500 Da can pass
• High Flux: large pores, molecules =<1500 Da cleared to appreciable degree

Question 4

Hemodialysis Flow RAtes

Answer 4

• Qb: 250-450 mL/min, affects clearance

- Qd: 500-800 mL/min

Question 5

Dialysate

Answer 5

• Ultrapure, water-based solution containing a physiologic concentration of electrolytes and glucose
• Contains “what you want blood to be”
• Adjust concentrations based on if you want the components to enter the serum or be filtered

Question 6

Vascular Access

Answer 6

• Arterio-venous fistula: connects artery to vein to balloon it to increase blood flow
• Arterio-venous graft: if vessels aren’t good enough this is another option
• Central venous catheter

Question 7

Hemodialysis Treatment

Answer 7

• 3 to 5 hours per session
• ESRD: 3x/week
• AKI: 3-7x/week

Question 8

ESRD Options

Answer 8

• Hemodialysis Center
• Home Dialysis
• Nocturnal Dialysis

Question 9

HD Complications

Answer 9

• Infection: 2nd leading cause of mortality
• Access site infections: Catheter>Graft>Fistules
• Access site thrombosis: Catheter>Graft>Fistules

Question 10

Peritoneal Dialysis: ESRD

Answer 10

• ~10% of ESRD dialysis patients in the U.S.
• Components: peritoneum (membrane), dialysate, access (Tenchoff catheter)
• Different types: CAPD, CCPD (AKA APD)

Question 11

CCPD

Answer 11

Continuous Cyclic Peritoneal Dialysis

Question 12

CAPD

Answer 12

Continuous Ambulatory Peritoneal Dialysis

Question 13

PD Complications

Answer 13

• Catheter-related infections: exit site, tunnel
• Peritonitis
• PD Infections guidelines provided by ISPD

Question 14

Peritonitis + RD

Answer 14

• Leading cause of morbidity
• 40-60% develop 1st episode within 1st year
• Results in hospitalization, termination of PD therapy, mortality

Question 15

Peritonitis

Answer 15

• Presentation: Cloudy dialysate, abdominal pain, fever, nausea
• Refer patient for follow up with dialysis center if present with cloud dialysate, and/or abdominal pain

Question 16

Drug Characteristics + Dialysis Considerations

Answer 16

• Molecular weight
• PPB (plasma protein binding)
• Vd

Question 17

Plasma Clearance

Answer 17

• If a drugs plasma clearance from dialysis is 25-30% or more of total clearance, it is considered clinically significant
• Clt = Clr + Clnr + Cld

Question 18

Dialysis Technicalities + Drug Removal

Answer 18

• Pore size: conventional or high-permeability is utilized
• Surface area
• Dialysis prescription