During dialysis, if an air detector alarm occurs but the machine is functioning, which event is expected?

• A. Air embolism
• B. Hypotension
• C. Circuit occlusion
• D. Blood pump has stopped

Answer: (D)

Air in the dialysis circuit is a dangerous threat because even tiny bubbles can travel to the patient and cause an air embolism. The machine is designed with a safety response: when the air detector senses bubbles, it stops the blood pump to prevent any air from advancing toward the patient, effectively isolating the risk. So, even if other parts of the machine continue to run, the critical action is the cessation of pumping to stop the flow of blood. After the pump stops, clinicians purge the line of air, re-prime with saline, and restart only when it’s safe. Other possibilities like hypotension or circuit occlusion are separate issues and not the immediate response to an air alarm.