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What This Guide Helps With
Troubleshooting unavailable, inaccurate, or unresponsive electronic fresh-gas flow control caused by supply, control, configuration, or gas-delivery system problems.
Step-by-Step Troubleshooting
1. Ensure Patient Safety First
Do not perform extended flow-control troubleshooting while the Avance is supporting an active patient.
If fresh-gas flow cannot be adjusted, displayed flow is questionable, or gas delivery is unstable:
- Notify the anesthesia provider immediately.
- Transfer the patient to another verified anesthesia machine or approved backup ventilation method.
- Maintain independent oxygenation, ventilation, and gas monitoring.
- Follow the facility’s anesthesia-machine failure procedure.
Expected: Patient care no longer depends on an anesthesia machine with uncertain fresh-gas delivery.
If the patient has been safely transferred or the machine is not in use, continue troubleshooting.
2. Confirm the Exact Failure Condition
Record the complete displayed alarm or message and determine whether the problem involves:
- Flow setting does not respond to control changes
- Total flow or oxygen percentage cannot be adjusted
- Displayed flow differs from measured or expected flow
- One gas is unavailable
- Fresh-gas flow stops unexpectedly
- Alternate O2 activates
- The issue occurs only during startup or checkout
Expected: The complaint is clearly defined and can be reproduced safely on a test circuit.
3. Check for Alternate O2 Operation
Inspect the Alternate O2 control and determine whether it has activated or was manually turned on.
Certain system failures may cause Alternate O2 to activate automatically. When active, normal electronic gas-control operation may be unavailable or altered.
- Confirm the control is fully in its intended position.
- Observe whether the display indicates Alternate O2 operation.
- Do not assume normal electronic flow control is functioning while Alternate O2 is active.
Expected: Alternate O2 status matches the selected operating condition.
If the control was unintentionally active and normal electronic flow control returns after proper reset and checkout, document the finding and stop.
4. Verify AC Power and Startup Condition
Confirm that:
- The power cord is fully connected.
- The wall outlet is functional and approved for medical equipment.
- The machine recognizes AC mains power.
- No power-related alarms are active.
- The system completes startup without freezing or repeatedly restarting.
Electronic gas control depends on stable system power and functional control electronics.
Expected: The Avance remains powered from AC mains and completes startup normally.
If power is unstable, correct the external power problem and repeat the manufacturer-approved checkout.
5. Verify Pipeline Gas Supplies
Check the connected O2, Air, and N2O pipeline supplies as equipped.
- Confirm each hose is connected to the correct wall outlet and machine inlet.
- Inspect hoses and fittings for damage, kinks, loose connections, or contamination.
- Verify adequate pipeline pressure using an approved test method.
- Test the wall outlet or use another verified outlet when permitted.
- Confirm that no facility medical-gas outage or maintenance condition is present.
Expected: Each required gas supply is correctly connected and available at the proper pressure.
If flow control returns after correcting a pipeline connection or pressure problem, complete a full checkout, document the repair, and stop.
6. Check Backup Cylinder Status
Inspect installed backup cylinders without interrupting any required gas supply.
- Confirm cylinders contain adequate pressure.
- Verify cylinder valves are fully closed during normal pipeline testing unless the approved procedure requires otherwise.
- Check for leaking or damaged cylinder yokes and seals.
- Confirm a partially open cylinder is not masking an unstable pipeline supply.
Expected: Backup cylinders are correctly installed and are not creating an abnormal supply condition.
7. Inspect External Controls and Display Response
Operate the fresh-gas flow controls in a controlled test environment.
- Confirm the control knob turns normally and is not physically damaged.
- Watch for consistent movement of the selected flow or oxygen concentration setting.
- Check whether selections skip, reverse, lag, or fail to register.
- Inspect the touchscreen and rotary control for contamination or interference.
- Confirm that no accessory, drape, or object is pressing against a control.
Expected: Each control input produces an immediate and consistent display response.
If the controls are physically damaged or intermittently unresponsive, remove the machine from service for repair.
8. Review Gas-Selection and Flow Settings
Confirm that the selected carrier gas, oxygen concentration, and total fresh-gas flow are appropriate for the test.
- Increase and decrease total flow through a safe test range.
- Adjust the oxygen concentration.
- Change the selected balance gas when the configuration permits.
- Observe whether the displayed gas mixture changes logically.
- Confirm that a low-flow setting is not being mistaken for loss of flow.
Expected: Displayed gas settings respond logically and remain stable after adjustment.
9. Inspect the Common Gas Outlet and Breathing-System Connections
Check the external gas-delivery path.
- Confirm the breathing system is fully seated.
- Inspect the common gas outlet or selectable common gas outlet configuration, if equipped.
- Verify external circuits and hoses are attached to the intended outlet.
- Check for disconnected, obstructed, kinked, or incorrectly routed tubing.
- Confirm the machine is not unintentionally configured to direct flow to an auxiliary breathing system.
GE identifies selectable common-gas-outlet components as part of the anesthesia machine’s breathing-circuit gas-delivery system.
Expected: Fresh gas is directed through the intended outlet without an external restriction or misconnection.
10. Inspect Vaporizers and External Accessories
Confirm that:
- Vaporizers are fully seated and locked.
- Only compatible vaporizers are installed.
- Vaporizer controls are in the OFF position during initial testing.
- No accessory attached to the gas pathway is visibly damaged, obstructed, or improperly installed.
- The issue does not occur only when one specific vaporizer or accessory is installed.
Expected: External accessories do not interfere with gas delivery or system checkout.
If removing a suspect accessory restores normal operation, quarantine the accessory and repeat the complete checkout.
11. Perform the Approved Machine Checkout
With no patient connected:
- Install the approved test circuit and test lung.
- Complete the manufacturer-approved preoperative checkout.
- Run the system leak and gas-delivery checks available to the operator.
- Observe total fresh-gas flow, oxygen concentration, alarms, and Alternate O2 behavior.
- Verify delivered oxygen concentration with a calibrated external analyzer when required by facility procedure.
The Avance breathing system is designed to support rapid control of fresh-gas flows, so delayed, unstable, or unavailable adjustment is not normal operation.
Expected: The system passes checkout, flow settings remain stable, and measured gas delivery agrees with the selected settings within applicable specifications.
If the machine passes all testing and the complaint cannot be reproduced, document the tests performed and return it to service only according to facility policy.
12. Compare With Known-Good External Components
When permitted, substitute known-good external items one at a time:
- Pipeline hose
- Wall gas outlet
- Power cord
- Breathing circuit
- Test lung
- Compatible vaporizer or accessory
Repeat the relevant functional check after each substitution.
Expected: A defective external component is isolated without opening the machine.
If a substituted component resolves the issue, replace or quarantine the failed item, complete the full checkout, and stop.
If the Problem Persists
If power, medical-gas supplies, controls, accessories, settings, outlet configuration, and external connections have been verified, the fault is likely within the electronic gas mixer, control electronics, valves, sensors, wiring, or related gas-delivery assemblies.
The device should be:
- Removed from service
- Labeled Out of Service
- Sent for qualified repair or bench evaluation
- Evaluated using the current GE Healthcare technical documentation and specified test equipment
Do not continue adjusting or replacing internal gas-control components without appropriate training, service documentation, and gas-delivery verification equipment.
Knowing when to stop is proper troubleshooting.
Clinical Use Tip
Never test uncertain electronic gas delivery on an active patient. Transfer the patient first and use independent oxygen, ventilation, and gas monitoring until another verified anesthesia machine is available.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Anesthesia staff reported that the Avance electronic fresh-gas flow setting would not respond and Alternate O2 activated during setup."
Cause
What was observed during troubleshooting.
Example:
"Pipeline supplies and external connections tested normally, but electronic flow adjustment remained unavailable during the approved machine checkout."
Resolution
What action was taken.
Example:
"Removed the Avance from service, labeled it Out of Service, provided a replacement machine, and forwarded the unit for electronic gas-delivery system evaluation."
Helpful Details to Include (If Known)
- Complete displayed alarm or message
- Whether Alternate O2 activated
- AC outlet tested
- Pipeline gas pressures verified
- Pipeline hoses inspected or swapped
- Backup cylinder pressures
- Flow and oxygen settings attempted
- External oxygen-analyzer reading
- Common gas outlet configuration
- Vaporizers or accessories installed
- Checkout or leak-test results
- Indicator lights or unusual display behavior
- Unusual sounds, heat, or smell
- Final device status
Final Thought
Electronic flow-control complaints require immediate attention because fresh-gas and oxygen delivery may be unreliable. Protect the patient, verify external supplies and controls logically, and escalate unresolved gas-delivery faults for qualified repair. Detailed CCR documentation supports safe follow-up and prevents repeated troubleshooting.
That is successful troubleshooting.