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Manufacturer
Model
What This Guide Helps With
Leak testing fails or the breathing system cannot maintain pressure because of circuit, connector, bag, filter, sampling-line, or assembly problems.
Step-by-Step Troubleshooting
1. Protect the Patient and Maintain Ventilation
Do not troubleshoot a suspected breathing-system leak while a patient depends on the affected machine. Move the patient to an appropriate verified ventilation and anesthesia-delivery method before manipulating the breathing system. Expected outcome: The patient is safely supported independently of the affected breathing system. If safe continuity cannot be established, stop troubleshooting and escalate immediately.
2. Confirm the Reported Leak Condition
Determine whether the issue occurs during an automated leak test, system test, manual ventilation, mechanical ventilation, or clinical operation. Record any displayed message and whether the leak is constant or intermittent. Reproduce the condition only in a non-patient setup. Expected outcome: The leak condition is clearly identified and reproducible. If the system passes repeated leak testing without correction, inspect for intermittent connection problems before release.
3. Inspect the Patient Circuit
Examine inspiratory and expiratory limbs, connectors, elbows, Y-piece, reservoir bag, filters, adapters, and other external circuit components. Look for loose fittings, cracks, cuts, deformation, disconnected ports, or incorrectly assembled components. Reconnect or replace suspect disposable or approved external components as appropriate. Expected outcome: The patient circuit is complete, intact, and securely connected. If replacing or reconnecting an external component allows the leak test to pass, proceed to final verification.
4. Check Open or Unused Ports
Inspect sampling ports, accessory ports, drain connections, and other externally accessible openings associated with the breathing system. Verify caps, plugs, adapters, and connected accessories are correctly installed where required. Expected outcome: No unintended opening remains in the breathing system. If closing or correctly connecting a port resolves the leak, repeat the leak test and stop after successful final verification.
5. Verify Reservoir Bag and Bag Connection
Inspect the reservoir bag and its connection for tears, loose seating, deformation, or damage. Substitute a known-good compatible bag when appropriate. Expected outcome: The bag and its connection are leak-free. If a known-good bag resolves the failure, repeat the required test and proceed to return-to-service verification.
6. Inspect Externally Accessible Breathing-System Components
Verify removable externally accessible breathing-system components are fully seated and assembled correctly. Inspect seals and mating surfaces that can be checked without deep disassembly for contamination, visible damage, or improper seating. Do not perform internal pneumatic repair or unsupported disassembly. Expected outcome: Externally accessible breathing-system components are correctly assembled and seated. If reseating them resolves the leak test failure, repeat the complete test sequence.
7. Use Controlled Isolation or Known-Good Substitution
Where permitted by facility practice and manufacturer documentation, simplify the external setup or substitute known-good compatible circuit components one at a time to identify whether the leak follows a particular accessory. Avoid changing multiple components simultaneously when doing so would obscure the cause. Expected outcome: A defective external accessory is identified or external accessories are ruled out. If the leak disappears with a known-good component, replace the defective item and verify normal operation.
8. Repeat the Leak or System Test
Reassemble the machine in its normal test configuration and repeat the appropriate system or leak test. Ensure the setup remains undisturbed during testing. Expected outcome: The machine passes the leak test consistently. If it does, troubleshooting can stop after final functional verification.
9. Perform Final Functional Verification
Verify ventilation operation, circuit integrity, pressure generation, alarm behavior, and all applicable system checks using approved test equipment and facility procedures. Expected outcome: The machine passes required leak, ventilation, and alarm checks and is suitable for return to service.
10. Escalate a Persistent Leak
If the leak remains after all external circuit and accessible assembly causes have been ruled out, remove the machine from service. Do not attempt internal pneumatic repairs beyond authorized Clinical Engineering scope. Expected outcome: The unresolved machine is routed for qualified service evaluation.
If the Problem Persists
Common external causes such as damaged circuits, loose connectors, reservoir bags, open ports, filters, accessory connections, and externally accessible breathing-system assembly have been ruled out. Remaining causes may involve an internal breathing-system seal, valve, pneumatic pathway, pressure-sensing path, or other service-level condition. The device should be:
- Removed from service
- Labeled Out of Service
- Sent for repair or bench evaluation
- Evaluated using appropriate manufacturer documentation and approved test equipment
- Repaired or configured only by qualified personnel
Following repair, perform all applicable leak tests, system checks, ventilation verification, alarm testing, and return-to-service testing. Knowing when to stop external troubleshooting is proper troubleshooting.
Clinical Use Tip
A small breathing-system leak can affect delivered volume and anesthetic delivery, so never dismiss a leak solely because ventilation appears to continue.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Anesthesia staff reported the Drager Atlan A350 repeatedly failed the breathing-system leak test."
Cause
What was observed during troubleshooting.
Example:
"Clinical Engineering found a cracked patient circuit connector that allowed a measurable external leak."
Resolution
What action was taken.
Example:
"Clinical Engineering replaced the damaged circuit component, repeated the leak and system tests successfully, and verified normal ventilation before return to service."
Helpful Details to Include (If Known)
- Exact leak-test message
- Whether failure was constant or intermittent
- Circuit type and condition
- Reservoir bag condition
- Filters and adapters installed
- Sampling or accessory ports checked
- Known-good substitutions
- Leak-test result before correction
- Leak-test result after correction
- Final device status
- Exact leak-test message
- Whether failure was constant or intermittent
- Circuit type and condition
- Reservoir bag condition
- Filters and adapters installed
- Sampling or accessory ports checked
- Known-good substitutions
- Leak-test result before correction
- Leak-test result after correction
- Final device status
Final Thought
Maintain safe patient support, inspect the complete external breathing path logically, verify the correction with formal leak testing, and escalate persistent leaks rather than assuming or attempting unsupported internal repair. That is successful troubleshooting.