CHT Certified Hemodialysis Technologist/Technician 2 — Questions and Answers
Question 1: Which type of vascular access has the highest long-term patency rate for hemodialysis?
- Temporary tunneled catheter
- Arteriovenous fistula (AVF) (Correct answer)
- Arteriovenous graft (AVG)
- Non-tunneled catheter
Correct answer: Arteriovenous fistula (AVF)
AVFs have the highest long-term patency and lowest infection risk, making them the preferred vascular access for hemodialysis.
Question 2: A patient's pre-dialysis BUN is 80 mg/dL and post-dialysis BUN is 20 mg/dL. What is the URR?
- 60%
- 75% (Correct answer)
- 80%
- 25%
Correct answer: 75%
URR = (pre-BUN − post-BUN) / pre-BUN × 100 = (80 − 20) / 80 × 100 = 75%.
Question 3: Ultrafiltration in hemodialysis refers to the removal of:
- Urea and creatinine by diffusion
- Excess fluid by convection (Correct answer)
- Phosphorus by adsorption
- Potassium by active transport
Correct answer: Excess fluid by convection
Ultrafiltration removes excess fluid from the blood via convective transport driven by transmembrane pressure.
Question 4: Which electrolyte imbalance is most immediately life-threatening during dialysis if not corrected?
- Hypocalcemia
- Hyperkalemia (Correct answer)
- Hyperphosphatemia
- Hyponatremia
Correct answer: Hyperkalemia
Severe hyperkalemia can cause fatal cardiac arrhythmias and is a primary indication for emergent dialysis.
Question 5: What is the purpose of the dialysate bicarbonate concentration during hemodialysis?
- To increase blood pressure
- To correct metabolic acidosis (Correct answer)
- To reduce phosphorus levels
- To prevent clotting in the circuit
Correct answer: To correct metabolic acidosis
Bicarbonate in dialysate diffuses into the blood to buffer acids and correct the metabolic acidosis common in ESRD patients.
Question 6: When priming a hemodialysis circuit, the primary goal is to:
- Test the blood pump speed
- Remove air and prepare the circuit with saline (Correct answer)
- Measure the transmembrane pressure
- Set the ultrafiltration rate
Correct answer: Remove air and prepare the circuit with saline
Priming flushes air from the blood lines and dialyzer, replacing it with saline to prevent air embolism.
Question 7: A dialysis patient reports muscle cramps during treatment. The most appropriate initial intervention is:
- Increase the blood flow rate
- Administer IV normal saline or hypertonic saline bolus (Correct answer)
- Decrease the dialysate temperature to 35°C
- Discontinue dialysis immediately
Correct answer: Administer IV normal saline or hypertonic saline bolus
Muscle cramps during dialysis are often caused by rapid fluid removal; a saline bolus helps restore intravascular volume and relieve cramps.
CHT Certified Hemodialysis Technologist/Technician 2
Which type of vascular access has the highest long-term patency rate for hemodialysis?