CHT Certified Hemodialysis Technician 3 — Questions and Answers
Question 1: During hemodialysis, the venous pressure alarm goes high and the blood pump stops. The first action the technician should take is:
- Clamp the venous line and check for kinks or occlusion (Correct answer)
- Increase the blood pump speed to overcome the resistance
- Immediately remove the venous needle
- Administer a saline bolus to the patient
Correct answer: Clamp the venous line and check for kinks or occlusion
A high venous pressure alarm indicates downstream resistance; clamping and inspecting the venous line for kinks or clotted segments is the correct initial response.
Question 2: The process of ultrafiltration during hemodialysis is driven primarily by:
- Osmotic pressure gradient across the membrane
- Hydrostatic transmembrane pressure (Correct answer)
- Concentration gradient of solutes
- Electrostatic charge differences
Correct answer: Hydrostatic transmembrane pressure
Ultrafiltration (fluid removal) is driven by transmembrane pressure, the hydrostatic pressure difference between the blood and dialysate compartments across the membrane.
Question 3: A technician notices the dialysate conductivity reading is consistently 12.5 mS/cm instead of the target of 14.0 mS/cm. The most likely cause is:
- Dialysate temperature is too high
- Acid concentrate ratio is too low
- Bicarbonate concentrate is depleted or supply line is kinked (Correct answer)
- Reverse osmosis water pressure is elevated
Correct answer: Bicarbonate concentrate is depleted or supply line is kinked
Low conductivity typically results from insufficient concentrate delivery; a depleted or blocked bicarbonate supply line reduces the total ionic content of the dialysate.
Question 4: Heparin is administered during hemodialysis primarily to prevent:
- Hypotension during fluid removal
- Clotting of blood in the extracorporeal circuit (Correct answer)
- Bacterial growth in the blood lines
- Dialyzer membrane degradation
Correct answer: Clotting of blood in the extracorporeal circuit
Heparin anticoagulates the blood as it passes through the extracorporeal circuit to prevent clot formation in the dialyzer fibers and blood tubing.
Question 5: Which of the following is the correct procedure when an air detector alarm sounds during hemodialysis?
- Silence the alarm and continue treatment at reduced pump speed
- Clamp the venous line immediately and stop the blood pump (Correct answer)
- Flush the circuit with saline to push air back to the dialyzer
- Increase ultrafiltration rate to compensate
Correct answer: Clamp the venous line immediately and stop the blood pump
When an air detector alarm triggers, the venous line must be clamped immediately and the blood pump stopped to prevent air embolism from reaching the patient.
Question 6: A patient with a tunneled cuffed catheter has blood flow rates consistently below 250 mL/min despite repositioning. The most appropriate next step is:
- Increase heparin dose and continue treatment
- Reverse the lines (arterial to venous port) as a temporary measure
- Notify the charge nurse or physician of suspected catheter malfunction (Correct answer)
- Increase blood pump speed to force higher flows
Correct answer: Notify the charge nurse or physician of suspected catheter malfunction
Persistent low flow rates despite repositioning suggest catheter dysfunction (fibrin sheath or thrombus) that requires physician evaluation and possible intervention.
Question 7: The term 'interdialytic weight gain' refers to fluid accumulated between treatments, and a typical acceptable limit per treatment interval is:
- 0.5–1.0 kg
- 1.0–2.0 kg
- 2.0–5.0 kg (Correct answer)
- 5.0–8.0 kg
Correct answer: 2.0–5.0 kg
Most centers target an interdialytic weight gain of 2–5 kg (roughly 1 kg per day) as the acceptable range for thrice-weekly patients.
CHT Certified Hemodialysis Technician 3
During hemodialysis, the venous pressure alarm goes high and the blood pump stops.
The first action the technician should take is: