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What This Guide Helps With
This guide assists Clinical Engineering in troubleshooting Puritan Bennett 560 ventilators that trigger circuit disconnect alarms. These alarms indicate that the ventilator senses a break or leak in the breathing circuit, which can compromise patient ventilation. Most causes are external or easily verifiable, such as loose tubing, disconnections, or obstructions, before considering internal device faults.
Step-by-Step Troubleshooting
Verify Patient Safety First
- Ensure the patient is stable and ventilated by another device or manual ventilation if needed.
- Never troubleshoot an active patient on the affected ventilator.
Check Circuit Connections
- Inspect all tubing connections from the ventilator to the patient.
- Ensure inspiratory and expiratory limbs are properly seated.
- Confirm humidifier, filters, and adapters are correctly installed.
- Loose or misaligned connections are the most common cause of disconnect alarms.
Inspect for Leaks or Damage
- Check the circuit for cracks, holes, or kinks.
- Ensure all ports on the ventilator and patient interface are sealed.
- Replace any damaged tubing or connectors.
Verify Flow Sensors and Adapters
- Inspect the flow sensor, if used, for proper placement and cleanliness.
- Make sure any D-lite or patient adapters are seated correctly.
Check Ventilator Settings
- Confirm the ventilator mode matches the circuit configuration (e.g., single limb vs. dual limb).
- Ensure tidal volume and alarms are appropriately set.
Power Cycle the Ventilator
- Turn the ventilator off and back on to clear false alarms after verifying the circuit is intact.
Observe Alarm Behavior
- If alarms persist, note whether they occur immediately upon connection or intermittently during operation.
- Document any unusual sounds, leaks, or error codes.
If the Problem Persists
If all external checks are complete and the alarms continue, the issue may be internal (pressure sensors or flow circuitry).
Action:
- Remove the ventilator from service.
- Label “Out of Service.”
- Send for repair or bench evaluation.
Knowing when to escalate is part of proper troubleshooting.
Clinical Use Tip
- Always maintain an alternative ventilation method before troubleshooting.
- Do not attempt internal sensor replacement on the floor; escalate to repair.
- Regularly inspect circuits and connectors to prevent alarms during patient care.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
User reports repeated “circuit disconnect” alarms while ventilating patient.
Cause
What was observed during troubleshooting.
Example:
Loose expiratory limb connection and kinked inspiratory tubing observed during inspection.
Resolution
What action was taken.
Example:
Reconnected tubing securely, replaced damaged sections, verified circuit integrity, ventilator returned to service.
Helpful Details to Include
- Outlet tested and confirmed working
- Tubing and connectors checked
- Flow sensor placement verified
- Alarm cleared after reconnection
- No unusual sounds, heat, or odor detected
Final Thought
Proper troubleshooting prioritizes patient safety, starts with simple external checks, and avoids unnecessary internal interventions. Documenting actions clearly ensures continuity of care and supports cost-effective maintenance.
That is successful troubleshooting.