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What This Guide Helps With
This guide addresses the O2% high alarm, which indicates the measured oxygen concentration is higher than the set FiO2. This can lead to inaccurate oxygen delivery and potential patient safety risks such as oxygen toxicity or improper ventilation management.
Step-by-Step Troubleshooting
Ensure Patient Safety First
- Assess the patient’s respiratory status immediately
- Provide alternate ventilation if oxygen delivery is uncertain
- Do not troubleshoot while supporting an unstable patient
Verify the Reported Alarm and Behavior
- Confirm the O2% high alarm is active on the display
- Compare set FiO2 to measured FiO2 values
- Observe if readings are consistently higher than expected
Check Oxygen Supply Source
- Verify correct gas connections (O2 and Air are not swapped)
- Confirm wall gas supply pressures are within normal range
- Ensure no external oxygen source is delivering excess concentration
Inspect Gas Supply Connections
- Check hoses for secure connections
- Inspect for kinks, damage, or contamination
- Reseat all gas connections if needed
Check Ventilator Settings
- Verify FiO2 setting matches clinical intent
- Confirm no recent unverified changes were made
- Ensure alarm limits are set appropriately
Calibrate the Oxygen Sensor
- Initiate oxygen sensor calibration through the interface
- Follow calibration prompts fully
- Ensure calibration completes without interruption
Perform System Test (SST)
- Run a full system self-test
- Observe for failures related to gas delivery or sensing
- Confirm system passes all checks
Stop When Resolved
- Confirm FiO2 readings are accurate and stable
- Clear the alarm
- Return the device to service only after verification
If the Problem Persists
If the O2% high alarm continues after calibration and external checks, internal sensor failure or gas mixing issues are likely.
- Remove the ventilator from service
- Label the device as Out of Service
- Send for repair or bench evaluation
Clinical Use Tip
Never troubleshoot a ventilator while it is actively supporting a patient. Always transfer the patient to a backup device before performing troubleshooting steps.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Ventilator alarming O2% high with measured FiO2 above set value during use."
Cause
What was observed during troubleshooting.
Example:
"Oxygen sensor drift causing inaccurate high FiO2 readings."
Resolution
What action was taken.
Example:
"Calibrated oxygen sensor and verified proper FiO2 readings; removed from service if issue persisted."
Helpful Details to Include (If Known)
- Alarm behavior
- Accessories swapped
- Power behavior
- Environmental factors
- Indicator lights
- Final device status
Final Thought
Oxygen concentration accuracy is critical to safe ventilation. Always verify actual delivery, prioritize external checks, and escalate quickly when readings cannot be trusted.
That is successful troubleshooting.