CDN Dialysis Adequacy and Prescription 2 — Questions and Answers
Question 1: Which dialysate potassium concentration is most appropriate for a patient with a pre-dialysis serum potassium of 6.5 mEq/L?
- 4 mEq/L
- 3 mEq/L
- 2 mEq/L (Correct answer)
- 1 mEq/L
Correct answer: 2 mEq/L
A 2 mEq/L potassium dialysate bath creates a favorable gradient for potassium removal in significantly hyperkalemic patients while reducing cardiac arrhythmia risk.
Question 2: What is the primary purpose of sodium profiling during hemodialysis?
- Prevent hypernatremia
- Improve cardiovascular stability and reduce intradialytic hypotension (Correct answer)
- Increase potassium removal
- Reduce bicarbonate concentration
Correct answer: Improve cardiovascular stability and reduce intradialytic hypotension
Sodium profiling uses higher sodium concentrations early in treatment to maintain plasma osmolality and improve hemodynamic stability, reducing intradialytic hypotension.
Question 3: A patient on hemodialysis has a target dry weight of 72 kg and arrives weighing 75.5 kg. What is the interdialytic weight gain, and is it within recommended limits?
- 2.5 kg — within limits
- 3.5 kg — exceeds the recommended 2–3 kg limit (Correct answer)
- 3.5 kg — within limits for a 72 kg patient
- 1.5 kg — below recommended minimum
Correct answer: 3.5 kg — exceeds the recommended 2–3 kg limit
The interdialytic weight gain is 3.5 kg (75.5 − 72 = 3.5), which exceeds the generally recommended limit of 2–3 kg between sessions.
Question 4: What is the maximum recommended ultrafiltration rate to minimize cardiovascular stress during hemodialysis?
- 5 mL/kg/hour
- 10 mL/kg/hour
- 13 mL/kg/hour (Correct answer)
- 20 mL/kg/hour
Correct answer: 13 mL/kg/hour
Ultrafiltration rates exceeding 13 mL/kg/hour are associated with increased cardiovascular stress, myocardial stunning, and higher mortality risk.
Question 5: Which dialysate bicarbonate concentration is typically used for hemodialysis patients with metabolic acidosis?
- 20–22 mEq/L
- 25–28 mEq/L
- 35–38 mEq/L (Correct answer)
- 45–50 mEq/L
Correct answer: 35–38 mEq/L
A dialysate bicarbonate of 35–38 mEq/L provides a diffusion gradient to correct metabolic acidosis common in end-stage renal disease patients.
Question 6: What blood flow rate and dialysate flow rate combination best optimizes small solute clearance during standard hemodialysis?
- Qb 200 mL/min / Qd 300 mL/min
- Qb 300 mL/min / Qd 500 mL/min (Correct answer)
- Qb 150 mL/min / Qd 800 mL/min
- Qb 500 mL/min / Qd 200 mL/min
Correct answer: Qb 300 mL/min / Qd 500 mL/min
A blood flow of 300 mL/min with a dialysate flow of 500 mL/min is the standard prescription that balances solute clearance efficiency with patient tolerance.
CDN Dialysis Adequacy and Prescription 2
Which dialysate potassium concentration is most appropriate for a patient with a pre-dialysis serum potassium of 6.5 mEq/L?