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What This Guide Helps With
Alarm: No O₂ supply indicating loss of oxygen delivery due to disconnected source or inadequate supply pressure, which can result in failure to maintain proper FiO₂ and patient oxygenation.
Step-by-Step Troubleshooting
1. Ensure Patient Safety First
- Immediately assess the patient
- Provide alternate ventilation or oxygen source if needed
- Prepare backup ventilator or bag-valve mask
2. Verify the Reported Alarm and Behavior
- Confirm the ventilator is displaying the “No O₂ supply” alarm
- Observe if alarm occurs at startup or during ventilation
- Check for unexpected drop in FiO₂
- Verify audible and visual alarms are active
3. Check Oxygen Source Connection (Most Common Cause)
- Ensure oxygen hose is securely connected to wall outlet or cylinder
- Verify quick-connect fittings are fully seated
- Check for loose or partially connected fittings
4. Verify Oxygen Supply Pressure
- Test wall outlet using another device or analyzer
- If using a cylinder, confirm it is open and has adequate pressure
- Ensure pressure is within normal range (~50 psi typical)
5. Inspect Oxygen Hose and Fittings
- Check for kinks, cracks, or visible damage
- Replace hose with a known-good one if available
- Ensure no restrictions to gas flow
6. Check for Cross-Connection or Misconnection
- Confirm oxygen hose is connected to correct gas outlet
- Ensure it is not connected to air or another gas source
- Verify proper routing to the ventilator O₂ inlet
7. Test with Alternate Oxygen Source
- Connect ventilator to a known-good oxygen outlet or cylinder
- Observe if the alarm clears
- Determine if issue is facility supply or device-related
8. Power Cycle and Reinitialize System
- Restart the ventilator after confirming oxygen supply is present
- Allow full system initialization
- Check if alarm clears after restart
If the Problem Persists
If oxygen supply, pressure, and connections are verified and the alarm continues, internal oxygen sensing or pneumatic system failure is likely.
- Remove device from service
- Label Out of Service
- Send for repair or bench evaluation
Clinical Use Tip
Never troubleshoot oxygen supply alarms on an active patient. Always transition the patient to a backup ventilation method before beginning troubleshooting.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Ventilator alarming 'No O₂ supply' and unable to maintain FiO₂."
Cause
What was observed during troubleshooting.
Example:
"Oxygen hose found disconnected from wall outlet."
Resolution
What action was taken.
Example:
"Reconnected oxygen supply, verified pressure, and confirmed alarm cleared."
Helpful Details to Include (If Known)
- Alarm behavior
- Accessories swapped
- Power behavior
- Environmental factors
- Indicator lights
- Final device status
Final Thought
Oxygen supply alarms represent immediate patient safety risks. Always verify external sources first and escalate appropriately if unresolved.
That is successful troubleshooting.