CERTIFIED DIALYSIS NURSE (CDN) EXAM
2026/2027 - COMPLETE TEST BANK WITH 200
REAL EXAM QUESTIONS & VERIFIED ANSWERS
1. A patient's prescribed dialysate flow rate is 500 mL/min. The actual measured flow is 420
mL/min. What is the most appropriate action?
A) Document the flow and continue treatment
B) Increase blood flow to compensate
C) Troubleshoot the dialysate delivery system
D) Notify the nephrologist after the session
Answer C: Troubleshoot the dialysate delivery system
Rationale: Dialysate flow below prescription reduces clearance. The nurse should troubleshoot (check
connectors, pump, alarms) before or immediately after starting; continuing may lead to inadequate
dialysis .
2. During priming of a dialyzer, air bubbles remain in the header after saline flushes. What should
the nurse do next?
A) Begin treatment; air will be trapped in the air detector
B) Tap the dialyzer gently and continue priming
C) Discard the dialyzer and prime a new one
D) Increase saline flow rate to 300 mL/min
Answer B: Tap the dialyzer gently and continue priming
Rationale: Tapping helps dislodge air bubbles trapped in the fiber bundle or header. Small bubbles can
cause clotting or air emboli risk if not removed .
,3. A patient on high-flux hemodialysis has a post-dialysis BUN of 18 mg/dL and pre-dialysis BUN
of 70 mg/dL. Calculate the URR (nearest whole percent).
A) 60%
B) 74%
C) 65%
D) 80%
Answer B: 74%
Rationale: URR = (pre-BUN – post-BUN) / pre-BUN × 100. (70 – 18) / 70 × 100 = 74%. Target URR is
≥65% .
4. A patient has a pre-dialysis serum potassium of 6.2 mEq/L. Which dialysate potassium bath is
most appropriate?
A) 0.0 mEq/L
B) 2.0 mEq/L
C) 3.0 mEq/L
D) 4.0 mEq/L
Answer B: 2.0 mEq/L
Rationale: A 2.0 mEq/L K+ bath is typical for hyperkalemia. Zero K+ can cause cardiac instability and
rapid K+ drop; 3.0 may not lower K+ enough .
5. A patient complains of chest pain and shortness of breath 30 minutes into HD. BP is 80/50
mmHg (baseline 130/80). What is the first action?
A) Give normal saline bolus
B) Stop ultrafiltration, check for air or blood leak
C) Decrease blood flow to 150 mL/min
D) Administer oxygen 2L NC
Answer B: Stop ultrafiltration, check for air or blood leak
Rationale: Hypotension with chest pain may indicate air embolism, hemolysis, or dialyzer reaction. Stop
UF first, then assess. Saline may worsen if cause is air .
,6. The hemodialysis machine alarms “low venous pressure.” What is the most likely cause?
A) Needle infiltration
B) Kinked venous line
C) Dislodged venous needle
D) Clotted dialyzer
Answer C: Dislodged venous needle
Rationale: Low venous pressure indicates loss of resistance downstream; dislodged venous needle or
line separation. Kinked line or clotted dialyzer increases pressure .
7. A patient’s target dry weight is 70.0 kg. Post-HD weight is 70.4 kg. The nurse should:
A) Document as target weight achieved
B) Increase ultrafiltration next session by 0.4 L
C) Decrease dry weight to 69.6 kg
D) Notify the provider immediately
Answer B: Increase ultrafiltration next session by 0.4 L
Rationale: The patient is 0.4 kg above target dry weight. UF should be adjusted to remove the excess
fluid next session.
8. Kt/V is a measure of:
A) Small molecule clearance normalized to volume of distribution
B) Middle molecule clearance
C) Urea reduction only
D) Convective clearance
Answer A: Small molecule clearance normalized to volume of distribution
Rationale: Kt/V is a dimensionless measure of small molecule (urea) clearance normalized to body water
volume. Target Kt/V is ≥1.2 for thrice-weekly hemodialysis .
, 9. Which of the following is the primary cause of anemia in patients with CKD?
A) Iron deficiency from poor dietary intake
B) Decreased erythropoietin production by the kidneys
C) Chronic blood loss through dialysis circuit
D) Vitamin B12 deficiency from restricted diet
Answer B: Decreased erythropoietin production by the kidneys
Rationale: The primary cause of anemia in CKD is decreased erythropoietin (EPO) production by
damaged kidneys. EPO stimulates red blood cell production .
10. Which component of the hemodialysis machine is responsible for detecting blood leaks?
A) Air detector
B) Blood leak detector
C) Venous pressure monitor
D) Conductivity monitor
Answer B: Blood leak detector
Rationale: The blood leak detector uses photoelectric sensors to detect blood in the dialysate (indicating
dialyzer membrane rupture). Air detectors prevent air embolism .
11. A dialysis patient is prescribed a phosphate binder. Which instruction should the nurse include
to ensure optimal effectiveness?
A) Take the binder with meals to bind dietary phosphate
B) Take the binder on an empty stomach before meals
C) Take the binder at bedtime to avoid interference with other medications
D) Take the binder with calcium supplements to enhance absorption
Answer A: Take the binder with meals to bind dietary phosphate
Rationale: Phosphate binders work by binding to phosphate in the GI tract, so they must be taken with
meals to be effective. Taking on an empty stomach or at bedtime would not coincide with dietary
phosphate intake .
2026/2027 - COMPLETE TEST BANK WITH 200
REAL EXAM QUESTIONS & VERIFIED ANSWERS
1. A patient's prescribed dialysate flow rate is 500 mL/min. The actual measured flow is 420
mL/min. What is the most appropriate action?
A) Document the flow and continue treatment
B) Increase blood flow to compensate
C) Troubleshoot the dialysate delivery system
D) Notify the nephrologist after the session
Answer C: Troubleshoot the dialysate delivery system
Rationale: Dialysate flow below prescription reduces clearance. The nurse should troubleshoot (check
connectors, pump, alarms) before or immediately after starting; continuing may lead to inadequate
dialysis .
2. During priming of a dialyzer, air bubbles remain in the header after saline flushes. What should
the nurse do next?
A) Begin treatment; air will be trapped in the air detector
B) Tap the dialyzer gently and continue priming
C) Discard the dialyzer and prime a new one
D) Increase saline flow rate to 300 mL/min
Answer B: Tap the dialyzer gently and continue priming
Rationale: Tapping helps dislodge air bubbles trapped in the fiber bundle or header. Small bubbles can
cause clotting or air emboli risk if not removed .
,3. A patient on high-flux hemodialysis has a post-dialysis BUN of 18 mg/dL and pre-dialysis BUN
of 70 mg/dL. Calculate the URR (nearest whole percent).
A) 60%
B) 74%
C) 65%
D) 80%
Answer B: 74%
Rationale: URR = (pre-BUN – post-BUN) / pre-BUN × 100. (70 – 18) / 70 × 100 = 74%. Target URR is
≥65% .
4. A patient has a pre-dialysis serum potassium of 6.2 mEq/L. Which dialysate potassium bath is
most appropriate?
A) 0.0 mEq/L
B) 2.0 mEq/L
C) 3.0 mEq/L
D) 4.0 mEq/L
Answer B: 2.0 mEq/L
Rationale: A 2.0 mEq/L K+ bath is typical for hyperkalemia. Zero K+ can cause cardiac instability and
rapid K+ drop; 3.0 may not lower K+ enough .
5. A patient complains of chest pain and shortness of breath 30 minutes into HD. BP is 80/50
mmHg (baseline 130/80). What is the first action?
A) Give normal saline bolus
B) Stop ultrafiltration, check for air or blood leak
C) Decrease blood flow to 150 mL/min
D) Administer oxygen 2L NC
Answer B: Stop ultrafiltration, check for air or blood leak
Rationale: Hypotension with chest pain may indicate air embolism, hemolysis, or dialyzer reaction. Stop
UF first, then assess. Saline may worsen if cause is air .
,6. The hemodialysis machine alarms “low venous pressure.” What is the most likely cause?
A) Needle infiltration
B) Kinked venous line
C) Dislodged venous needle
D) Clotted dialyzer
Answer C: Dislodged venous needle
Rationale: Low venous pressure indicates loss of resistance downstream; dislodged venous needle or
line separation. Kinked line or clotted dialyzer increases pressure .
7. A patient’s target dry weight is 70.0 kg. Post-HD weight is 70.4 kg. The nurse should:
A) Document as target weight achieved
B) Increase ultrafiltration next session by 0.4 L
C) Decrease dry weight to 69.6 kg
D) Notify the provider immediately
Answer B: Increase ultrafiltration next session by 0.4 L
Rationale: The patient is 0.4 kg above target dry weight. UF should be adjusted to remove the excess
fluid next session.
8. Kt/V is a measure of:
A) Small molecule clearance normalized to volume of distribution
B) Middle molecule clearance
C) Urea reduction only
D) Convective clearance
Answer A: Small molecule clearance normalized to volume of distribution
Rationale: Kt/V is a dimensionless measure of small molecule (urea) clearance normalized to body water
volume. Target Kt/V is ≥1.2 for thrice-weekly hemodialysis .
, 9. Which of the following is the primary cause of anemia in patients with CKD?
A) Iron deficiency from poor dietary intake
B) Decreased erythropoietin production by the kidneys
C) Chronic blood loss through dialysis circuit
D) Vitamin B12 deficiency from restricted diet
Answer B: Decreased erythropoietin production by the kidneys
Rationale: The primary cause of anemia in CKD is decreased erythropoietin (EPO) production by
damaged kidneys. EPO stimulates red blood cell production .
10. Which component of the hemodialysis machine is responsible for detecting blood leaks?
A) Air detector
B) Blood leak detector
C) Venous pressure monitor
D) Conductivity monitor
Answer B: Blood leak detector
Rationale: The blood leak detector uses photoelectric sensors to detect blood in the dialysate (indicating
dialyzer membrane rupture). Air detectors prevent air embolism .
11. A dialysis patient is prescribed a phosphate binder. Which instruction should the nurse include
to ensure optimal effectiveness?
A) Take the binder with meals to bind dietary phosphate
B) Take the binder on an empty stomach before meals
C) Take the binder at bedtime to avoid interference with other medications
D) Take the binder with calcium supplements to enhance absorption
Answer A: Take the binder with meals to bind dietary phosphate
Rationale: Phosphate binders work by binding to phosphate in the GI tract, so they must be taken with
meals to be effective. Taking on an empty stomach or at bedtime would not coincide with dietary
phosphate intake .
