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What This Guide Helps With
Fresh-gas flow problems caused by gas supply, control settings, connections, breathing-system setup, external obstruction, or service-level faults.
Step-by-Step Troubleshooting
1. Protect the Patient and Maintain Gas Delivery
Do not troubleshoot unreliable fresh-gas delivery while the patient depends on the affected machine. Establish another verified means of anesthesia and gas delivery first.
Expected outcome: Patient ventilation, oxygenation, and anesthetic delivery are safely maintained.
2. Confirm the Fresh-Gas Flow Complaint
Determine whether flow cannot be increased or decreased, one gas is affected, total flow is incorrect, the displayed flow does not respond, or fresh-gas delivery is absent.
Record the selected gases, controls used, and displayed values.
Expected outcome: The fresh-gas problem is reproduced and clearly characterized.
3. Verify Pipeline and Cylinder Gas Availability
Confirm required pipeline hoses are connected to the correct outlets, fully seated, and undamaged. Check available cylinder supplies when relevant to the test.
Compare behavior using an alternate verified supply source when appropriate and permitted.
Expected outcome: Adequate gas supply is available to the machine. If restoring the supply corrects fresh-gas flow, troubleshooting can stop after verification.
4. Inspect External Gas Connections
Check hoses, quick connectors, fittings, and accessible supply connections for kinks, mechanical damage, loose engagement, or incorrect gas connection.
Expected outcome: External gas pathways are correctly connected and unobstructed.
5. Verify Fresh-Gas Controls and Settings
Confirm the intended gas mixture and fresh-gas flow settings are selected using normal operating controls. Check whether an operating mode or setting is influencing expected fresh-gas behavior.
Do not alter service configuration or unauthorized settings.
Expected outcome: Controls respond normally and correspond with the intended test conditions.
6. Inspect the Breathing System for External Abnormalities
Check the breathing circuit and accessible gas-delivery path for incorrect assembly, obstruction, excessive leakage, or disconnected components that could make fresh-gas delivery appear abnormal.
Expected outcome: No external circuit problem is interfering with assessment of fresh-gas flow.
7. Repeat the System Test
Perform the normal system test after external gas-supply and setup issues have been corrected. Record any fresh-gas or gas-delivery related failure.
Expected outcome: The system test completes without fresh-gas delivery errors.
8. Verify Gas Delivery With Approved Test Equipment
When required for return-to-service testing, use an approved anesthesia-machine analyzer or flow-measurement device to verify fresh-gas response across the applicable operating checks.
Do not adjust internal calibration based solely on an unverified external instrument.
Expected outcome: Fresh-gas delivery responds consistently to selected controls and passes applicable performance checks.
9. Escalate Persistent Fresh-Gas Control Problems
If fresh-gas delivery remains absent, unstable, or inconsistent after external supply, controls, connections, and breathing-system conditions are verified, remove the machine from service.
Expected outcome: Further diagnosis is transferred to qualified bench service.
If the Problem Persists
Common external causes have been ruled out. The remaining problem may involve an internal gas-control valve, flow-measurement system, pneumatic pathway, electronic control system, or service-level configuration.
Remove the machine from service, label it Out of Service, and perform further evaluation using appropriate Drager documentation and approved gas-flow test equipment. Internal pneumatic or electronic repairs and calibration should be completed only by qualified personnel.
Verify system testing, fresh-gas delivery, oxygen concentration, ventilation, and relevant alarms before return to service.
Knowing when to stop external troubleshooting and escalate is proper troubleshooting.
Clinical Use Tip
Any uncertainty about fresh-gas or oxygen delivery warrants immediate transition to another verified anesthesia machine rather than continued clinical use.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"OR staff reported the Atlan A300 fresh-gas flow would not increase as expected during setup."
Cause
What was observed during troubleshooting.
Example:
"Clinical Engineering found the oxygen pipeline hose incompletely connected at the wall outlet."
Resolution
What action was taken.
Example:
"Corrected the pipeline connection, repeated the system test, verified fresh-gas control response with approved test equipment, and returned the machine to service."
Helpful Details to Include (If Known)
- Gas or gases affected
- Selected fresh-gas settings
- Displayed flow behavior
- Pipeline connections
- Cylinder availability
- Hose and connector condition
- Breathing-system configuration
- System-test result
- External analyzer or flow-test result
- Results before and after correction
- Final device status
Final Thought
Verify the gas source, external connections, and control settings before assuming internal flow-control failure, and never return a machine with uncertain gas delivery to clinical use.
That is successful troubleshooting.