Drager Fabius

Breathing System Leak or Leak Test Failure

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Asset Type

Anesthesia Machine

Manufacturer

Drager

Model

Fabius

What This Guide Helps With

Helps isolate external breathing-circuit, connection, accessory, valve, or configuration causes when the system will not hold pressure or passes an inadequate leak test.

Step-by-Step Troubleshooting

1. Protect the Patient and Maintain Anesthesia Support

Do not troubleshoot a suspected breathing-system leak while a patient depends on unreliable ventilation or anesthetic delivery. Transfer ventilation and anesthesia support to an alternate verified method or device as clinically appropriate.

Remove the Fabius from active patient use if the leak could affect ventilation, oxygenation, anesthetic delivery, or alarm performance.

Expected outcome: The patient is supported independently of the affected machine and troubleshooting can proceed safely.

2. Confirm the Exact Reported Condition

Ask clinical staff when the leak was observed and whether it occurred during a pre-use check, mechanical ventilation, manual ventilation, or after changing a circuit or accessory.

Repeat only an appropriate non-patient functional or leak evaluation using the approved setup.

Expected outcome: The leak or leak-test failure is reproduced consistently enough to troubleshoot. If the unit now passes all required checks and no intermittent condition remains, troubleshooting can stop after final verification.

3. Inspect the Breathing Circuit

Inspect inspiratory and expiratory limbs, patient Y-piece, reservoir bag, connectors, sampling adapters, filters, and other externally connected breathing-system components.

Look for:

Reseat connections without forcing them.

Expected outcome: All breathing-circuit components are intact and fully seated. If correcting a loose or damaged external component restores leak-test performance, troubleshooting can stop after final verification.

4. Check the Reservoir Bag and Manual Ventilation Connections

Inspect the breathing bag and its connection for tears, punctures, loose fittings, or incorrect installation. Verify that external manual ventilation components are connected as intended for the test being performed.

Substitute a compatible known-good bag when appropriate.

Expected outcome: The bag and associated connections do not leak. If a known-good replacement resolves the problem, document the failed accessory and proceed to final verification.

5. Inspect the Absorber and Breathing-System Assembly

Verify that accessible absorber components, canisters, breathing-system interfaces, seals, and removable assemblies are correctly installed and fully latched or seated.

Do not disassemble internal pneumatic assemblies beyond normal Clinical Engineering service access.

Expected outcome: Accessible breathing-system assemblies are correctly installed with no obvious seal damage, looseness, or misalignment. If reseating an external assembly eliminates the leak, troubleshooting can stop after verification.

6. Check External Sampling and Auxiliary Connections

Inspect gas-sampling lines and other external ports that communicate with the breathing system. Confirm unused ports are handled according to the normal device configuration and no line is cracked, disconnected, or unintentionally open.

Expected outcome: External sampling and auxiliary connections do not introduce a leak. If correction restores normal operation, continue to final verification.

7. Compare With Known-Good External Components

If the leak remains, substitute known-good compatible external circuit components one section at a time when practical. Avoid replacing multiple components simultaneously unless needed for safety.

Expected outcome: The leak either follows a specific external component or remains with the anesthesia machine. If the problem follows an accessory, replace that accessory and stop after successful testing.

8. Verify Controls and Test Configuration

Confirm the machine is configured correctly for the leak or checkout test being performed. Verify externally accessible controls are in the appropriate position and no breathing-system component has been left in an incompatible test configuration.

Do not alter restricted calibration or service settings.

Expected outcome: The machine and circuit are correctly configured for testing.

9. Perform Final Functional Verification

After any correction, perform the applicable manufacturer-approved checkout and leak verification using appropriate test equipment. Confirm ventilation, pressure generation, alarm behavior, and breathing-system integrity as applicable before return to service.

Expected outcome: The anesthesia machine passes the required functional checks without abnormal leakage. If it does, troubleshooting is complete.

10. Stop and Escalate if the Leak Remains

If the machine continues to fail leak testing after external components, connections, and configuration have been ruled out, do not continue increasingly invasive troubleshooting without approved service documentation.

Expected outcome: The unit is removed from service and escalated for qualified bench evaluation.

If the Problem Persists

Common external circuit, accessory, connection, and setup causes have been ruled out. Remaining possibilities may involve an internal pneumatic leak, sealing surface, valve assembly, breathing-system interface, pressure-control component, or other service-level fault.

The device should be:

Complete the required anesthesia-machine performance, leak, alarm, and safety testing before return to service.

Knowing when to stop external troubleshooting and escalate is proper troubleshooting.

Clinical Use Tip

Do not place an anesthesia machine back into service after a leak complaint until the complete breathing-system checkout passes with the intended circuit configuration.

Work Order Documentation (CCR Method)

CCR = Complaint, Cause, Resolution

Complaint

What was reported by the clinical staff.

Example:
"OR staff reported the Drager Fabius failed the breathing-system leak test before a case."

Cause

What was observed during troubleshooting.

Example:
"Clinical Engineering found a breathing-circuit connection partially seated at the machine interface."

Resolution

What action was taken.

Example:
"The connection was reseated, the circuit was inspected, and the machine passed the applicable leak and functional checks before return to service."

Helpful Details to Include (If Known)

Final Thought

Protect the patient first, then work logically from the breathing circuit and accessible connections inward. Verify the complete system before assuming an internal pneumatic fault, escalate when external causes are exhausted, and document the confirmed complaint, cause, and resolution clearly.

That is successful troubleshooting.

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