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What This Guide Helps With
PRESSURE NEGATIVE !!! alarm indicating airway pressure ≤ -6.5 cmH₂O, often caused by circuit leak, disconnection, or improper ventilator settings.
Step-by-Step Troubleshooting
1. Ensure Patient Safety First
- Remove the anesthesia machine from patient use if ventilation is unstable
- Provide alternate ventilation (bagging or backup machine)
2. Verify the Reported Alarm and Behavior
- Confirm PRESSURE NEGATIVE !!! alarm is displayed
- Check airway pressure readings for negative values
- Observe ventilation effectiveness (chest rise, volumes)
3. Check for Breathing Circuit Disconnection
- Inspect all hoses from machine to patient
- Verify Y-piece connection
- Check inspiratory and expiratory ports
4. Check for Leaks in the Breathing System
- Inspect for loose fittings or cracked hoses
- Ensure filters and components are properly seated
- Perform a leak check if available
5. Check APL Valve and Fresh Gas Flow
- Ensure APL valve is not fully open in Man/Spont mode
- Verify adequate fresh gas flow is set
6. Verify Ventilator Settings
- Check tidal volume or pressure settings
- Verify PEEP level
- Confirm correct ventilation mode
7. Inspect Flow Sensor and Components
- Ensure flow sensor is properly connected
- Check for obstruction or contamination
8. Isolate the Issue
- Swap breathing circuit or accessories with known-good components
- Determine if issue is accessory, configuration, or device related
9. Stop When Resolved
- Confirm normal airway pressure readings
- Clear alarms
- Return device to service
If the Problem Persists
If all external causes (circuit, leaks, settings, sensors) have been ruled out and the alarm continues:
- Remove the device from service
- Label Out of Service
- Send for repair or bench evaluation
Clinical Use Tip
Never troubleshoot a negative pressure condition on an active patient. Move the patient to a backup device before continuing.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Unit displaying PRESSURE NEGATIVE !!! alarm with low/negative airway pressure during ventilation."
Cause
What was observed during troubleshooting.
Example:
"Leak identified in breathing circuit at Y-piece connection causing inability to maintain airway pressure."
Resolution
What action was taken.
Example:
"Reconnected and secured circuit connections, verified no leaks, confirmed normal airway pressure readings, and returned unit to service."
Helpful Details to Include (If Known)
- Alarm behavior
- Accessories swapped
- Power behavior
- Environmental factors
- Indicator lights
- Final device status
Final Thought
Negative pressure alarms are often caused by simple issues like disconnections or leaks. Always start with external checks, verify system integrity, and escalate appropriately to ensure safe operation.
That is successful troubleshooting.