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What This Guide Helps With
This guide addresses the ↓O2% alarm indicating delivered oxygen concentration is below the set value, which can lead to inadequate oxygenation and increased patient risk.
Step-by-Step Troubleshooting
Ensure Patient Safety First
- Assess the patient’s oxygenation status immediately
- Provide supplemental oxygen or switch to backup ventilation if needed
- Confirm SpO₂ and clinical stability
Verify the Reported Alarm and Behavior
- Confirm the ↓O2% alarm is displayed
- Observe delivered FiO₂ compared to set FiO₂
- Note if alarm is continuous or intermittent
Check Oxygen Supply Source
- Ensure O₂ hose is securely connected to wall outlet
- Verify wall source is active using a known-good device
- Inspect hose for kinks, leaks, or disconnections
Inspect Oxygen Inlet Components
- Check oxygen inlet filter for blockage
- Verify all inlet fittings are secure
- Ensure no restriction in gas entry path
Perform O₂ Sensor Calibration
- Initiate calibration per manufacturer procedure
- Use appropriate calibration gas (room air or 100% O₂)
- Ensure stable gas source during calibration
Run Extended Self-Test (EST)
- Access service or maintenance menu
- Run EST and monitor for oxygen-related faults
Check Oxygen PSOL Function
- Observe if FiO₂ responds to setting adjustments
- Listen for proper valve actuation
- Identify inconsistent or unresponsive oxygen delivery
Replace Oxygen Sensor (If Needed)
- Replace sensor if calibration fails or readings remain inaccurate
- Recalibrate after replacement
- Verify FiO₂ accuracy post-installation
If the Problem Persists
If the ↓O2% alarm continues after completing all external checks, internal components such as the PSOL or control system may be at fault. Remove the device from service, label it Out of Service, and send it for repair or bench evaluation.
Clinical Use Tip
Never troubleshoot oxygen delivery issues on an active patient. Always transition the patient to a backup ventilator or manual ventilation before continuing diagnostics.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Ventilator alarming ↓O2% with delivered FiO₂ lower than set value during use."
Cause
What was observed during troubleshooting.
Example:
"Oxygen sensor failed calibration and showed inaccurate low FiO₂ readings."
Resolution
What action was taken.
Example:
"Replaced oxygen sensor, recalibrated system, verified accurate FiO₂ delivery, 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
Low oxygen alarms directly impact patient safety and must be addressed immediately. Always verify supply, calibration, and measurement accuracy before escalating to internal component failure.
That is successful troubleshooting.