✅ MCQs – Hemodialysis Machine: Circuit & Alarm System
1. Which of the following is most likely to trigger a venous pressure high alarm?
A. Bloodline disconnected
B. Kink in the venous line
C. Low blood flow rate
D. Arterial needle dislodgement
➡️ Answer: B. Kink in the venous line
2. A low arterial pressure alarm may be caused by:
A. Clot in dialyzer
B. Venous needle infiltration
C. Disconnection or air in arterial line
D. Saline flush
➡️ Answer: C. Disconnection or air in arterial line
3. The air detector alarm is usually located:
A. Before the blood pump
B. In the arterial line
C. After the venous drip chamber
D. In the dialysate line
➡️ Answer: C. After the venous drip chamber
4. A continuous blood leak alarm likely indicates:
A. Kink in blood tubing
B. Rupture of dialyzer fibers
C. Air in venous line
D. Overheated dialysate
➡️ Answer: B. Rupture of dialyzer fibers
5. Which of the following will not trigger a machine alarm?
A. Blood flow drops below set value
B. Patient moves during treatment
C. Dialysate temperature drifts outside range
D. Venous pressure line gets disconnected
➡️ Answer: B. Patient moves during treatment
6. The conductivity alarm alerts staff to:
A. Blood clotting in circuit
B. Incorrect dialysate concentration
C. Blood-air interface
D. Machine temperature overheating
➡️ Answer: B. Incorrect dialysate concentration
7. A TMP (transmembrane pressure) alarm high is most commonly caused by:
A. Low blood flow
B. Blocked ultrafiltration pump
C. Dialyzer clotting or fiber clogging
D. Low dialysate flow
➡️ Answer: C. Dialyzer clotting or fiber clogging
8. When the heparin pump fails, what is the potential risk?
A. Electrolyte imbalance
B. Dialysate contamination
C. Blood clotting in extracorporeal circuit
D. Blood pressure drop
➡️ Answer: C. Blood clotting in extracorporeal circuit
9. A temperature alarm on the machine typically indicates:
A. Room temperature fluctuation
B. Blood warmer malfunction
C. Dialysate out of safe range (35–37°C)
D. Patient has fever
➡️ Answer: C. Dialysate out of safe range (35–37°C)
10. What is the first action when a venous pressure low alarm occurs?
A. Increase ultrafiltration
B. Reset the alarm
C. Check for line disconnection or infiltration
D. Administer saline
➡️ Answer: C. Check for line disconnection or infiltration
11. If the blood pump stops during treatment, the most immediate concern is:
A. Infection
B. Electrolyte imbalance
C. Clotting in the extracorporeal circuit
D. Low dialysate flow
➡️ Answer: C. Clotting in the extracorporeal circuit
12. A blood leak detector alarm activates. The next step is to:
A. Increase blood flow
B. Flush with saline
C. Stop treatment and return blood if safe
D. Continue dialysis and observe
➡️ Answer: C. Stop treatment and return blood if safe
13. What could trigger a dialysate flow alarm?
A. Loose arterial connection
B. Power failure
C. Obstruction in dialysate lines or pump failure
D. Patient cramping
➡️ Answer: C. Obstruction in dialysate lines or pump failure
14. A venous pressure high alarm could indicate:
A. Arterial needle dislodgement
B. Venous needle infiltration or clot
C. Dialysate too cold
D. Conductivity too low
➡️ Answer: B. Venous needle infiltration or clot
15. Which alarm is designed to detect the risk of hemolysis?
A. Blood leak detector
B. Temperature alarm
C. Conductivity alarm
D. Air detector
➡️ Answer: C. Conductivity alarm
(Drastic changes in dialysate conductivity can lead to hemolysis.)
16. A TMP high alarm occurs due to:
A. Air in the circuit
B. Excessive ultrafiltration pressure
C. Normal blood flow rate
D. Low venous pressure
➡️ Answer: B. Excessive ultrafiltration pressure
17. What causes a low venous pressure alarm in a functioning circuit?
A. Venous needle dislodgement
B. Blood pump too fast
C. High TMP
D. Dialysate pump failure
➡️ Answer: A. Venous needle dislodgement
18. Which of the following actions is most appropriate if the air detector alarm activates?
A. Increase blood flow
B. Clamp the venous line and stop the pump
C. Silence the alarm and continue
D. Recalibrate the machine
➡️ Answer: B. Clamp the venous line and stop the pump
19. A low arterial pressure alarm is most commonly caused by:
A. High blood viscosity
B. Patient coughing
C. Kinked or occluded arterial needle/tubing
D. Dialysate flow too high
➡️ Answer: C. Kinked or occluded arterial needle/tubing
20. The UF (ultrafiltration) error alarm means:
A. Blood leak detected
B. UF volume not matching programmed settings
C. Dialysate conductivity too high
D. Blood pressure is low
➡️ Answer: B. UF volume not matching programmed settings
