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What This Guide Helps With
Helps isolate gas-supply, control-position, accessory, flow-measurement, connection, or configuration causes when fresh gas flow cannot be adjusted normally or appears inaccurate.
Step-by-Step Troubleshooting
1. Protect the Patient and Anesthetic Delivery
Do not troubleshoot unreliable fresh-gas delivery while a patient depends on the affected anesthesia machine. Transfer care to an alternate verified anesthesia system.
Expected outcome: Oxygen and anesthetic-gas delivery remain reliable while the Fabius is evaluated off-patient.
2. Confirm Which Gas and Control Are Affected
Determine whether the concern involves oxygen, air, nitrous oxide, multiple gases, a control that will not respond, or a discrepancy between selected and measured flow.
Reproduce the concern using approved bench test equipment.
Expected outcome: The affected gas channel and symptom are clearly identified.
3. Verify Gas Supplies
Confirm the appropriate pipeline and/or cylinder supplies are available, connected, and adequate for testing. Check whether the problem changes when using an approved alternate gas source configuration.
Expected outcome: The machine has a valid upstream gas supply. If restoring the gas source resolves the problem, proceed to final verification.
4. Inspect External Gas Connections
Inspect pipeline hoses, quick-connects, fittings, and accessible gas-supply interfaces for damage, incomplete engagement, contamination, or incorrect connection.
Do not defeat gas-specific connection safeguards.
Expected outcome: External supply connections are secure and appropriate for the intended gas.
5. Check Control Movement and Physical Condition
With the machine out of patient use, inspect the affected externally accessible flow control for abnormal looseness, binding, physical damage, or obstruction.
Do not force a stuck control.
Expected outcome: The control operates smoothly through its intended user-accessible range. If it remains mechanically abnormal, remove the unit from service.
6. Compare Flow With Approved Test Equipment
Use suitable gas-flow or anesthesia test equipment to independently measure fresh gas flow while adjusting the affected control.
Expected outcome: Actual gas flow changes appropriately with control input. If actual flow is normal but indication is abnormal, the issue is narrowed to measurement or display rather than delivery.
7. Check Related Settings and Gas Configuration
Verify that the selected gas source, gas configuration, and externally accessible settings are appropriate for the intended operation.
Do not change restricted gas configuration or service calibration values.
Expected outcome: No user-accessible configuration is preventing normal fresh-gas adjustment.
8. Compare Multiple Gas Channels
When safe and appropriate, determine whether the problem affects one gas or all fresh-gas controls. This helps distinguish a single-channel external problem from a broader supply or system issue.
Expected outcome: The scope of the fault is defined without invasive testing.
9. Perform Final Functional Verification
After any correction, verify actual fresh-gas flow using approved test equipment and complete the applicable machine checkout, including oxygen delivery and associated alarms.
Expected outcome: Fresh-gas controls respond normally and measured flow is acceptable under the approved procedure. If so, troubleshooting is complete.
10. Escalate Persistent Flow-Control Problems
If upstream supply, external connections, controls, configuration, and independent flow measurements remain abnormal, stop troubleshooting at the external level.
Expected outcome: The anesthesia machine is removed from service for internal pneumatic or control-system evaluation.
If the Problem Persists
External gas supply, hoses, controls, configuration, and measurement setup have been ruled out. Remaining possibilities may include internal flow-control, metering, gas-regulation, pneumatic, sensor, or control-interface faults.
The device should be:
- Removed from service
- Labeled Out of Service
- Sent for repair or bench evaluation
- Evaluated using appropriate manufacturer documentation and approved gas-flow test equipment
- Repaired, adjusted, or calibrated only by qualified personnel
Verify gas flow, oxygen delivery, gas monitoring, alarms, ventilation, and machine checkout requirements before return to service.
Clinical Use Tip
Any uncertainty in oxygen or fresh-gas delivery warrants immediate use of another verified anesthesia system rather than continued clinical troubleshooting.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Anesthesia staff reported that the oxygen fresh-gas control appeared to respond but the indicated flow remained low."
Cause
What was observed during troubleshooting.
Example:
"Clinical Engineering found the oxygen pipeline connection was not fully engaged at the machine supply hose."
Resolution
What action was taken.
Example:
"The connection was secured and oxygen flow was verified with approved test equipment through the applicable functional checkout."
Helpful Details to Include (If Known)
- Gas channel affected
- Pipeline or cylinder operation
- Supply pressure status if available from approved indicators
- Hose and connector condition
- Control movement
- Independent flow measurement
- Other gas channels tested
- Configuration observed
- Alarm results
- Final status
- Gas channel affected
- Pipeline or cylinder operation
- Supply pressure status if available from approved indicators
- Hose and connector condition
- Control movement
- Independent flow measurement
- Other gas channels tested
- Configuration observed
- Alarm results
- Final status
Final Thought
Fresh-gas problems should be approached from the supply source forward. Verify gas availability, connections, controls, and independent flow before concluding an internal metering problem exists, and escalate when the machine cannot be proven reliable.
That is successful troubleshooting.