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What This Guide Helps With
Troubleshooting elevated PEEP or incomplete exhalation caused by circuit restrictions, valve problems, scavenging issues, moisture, accessories, or incorrect ventilator settings.
Step-by-Step Troubleshooting
1. Ensure Patient Safety First
Do not perform extended troubleshooting while the Avance is supporting an active patient.
If expiratory pressure remains elevated during a procedure:
- Notify the anesthesia provider immediately.
- Move ventilation to another verified anesthesia machine or approved backup method.
- Maintain appropriate independent patient monitoring.
- Follow the facility’s anesthesia-machine failure procedure.
Expected: Patient ventilation no longer depends on equipment with unresolved elevated expiratory pressure.
If the patient is safely supported by another device, continue troubleshooting in a controlled Clinical Engineering setting.
2. Confirm the Reported Condition
Review the alarm history and determine whether the issue involves:
- PEEP above the selected value
- Airway pressure failing to return to baseline
- Continuous positive pressure between breaths
- Slow or incomplete exhalation
- Bellows failing to refill normally
- The issue occurring only in one ventilation mode
Record the selected PEEP, measured PEEP, airway-pressure waveform, ventilation mode, respiratory rate, and tidal volume.
Expected: The complaint is clearly defined and can be reproduced using a test lung.
3. Verify Ventilator Settings
Check that:
- The selected PEEP is appropriate for the test.
- The respiratory rate is not excessively high.
- Inspiratory time is not too long.
- The inspiratory-to-expiratory ratio allows adequate exhalation.
- Tidal volume and flow settings are reasonable for the attached test lung.
- Pressure-control settings are not being mistaken for elevated PEEP.
Return settings to a known test configuration when appropriate.
Expected: Expiratory pressure returns to the selected PEEP level.
If correcting the settings resolves the issue, complete operational testing and stop.
4. Inspect the Patient Circuit
Disconnect the circuit from clinical use and inspect the full breathing path for:
- Kinked or compressed tubing
- Tubing trapped under equipment
- Water accumulation
- Occluded filters
- Incorrectly installed connectors
- Collapsed flexible tubing
- Restricted masks, elbows, adapters, or sampling accessories
- Excessively long or complex circuit configurations
Replace questionable components with known-good compatible accessories.
Expected: Gas can flow freely through the inspiratory and expiratory limbs.
If replacing the circuit resolves the issue, complete a system checkout and stop.
5. Check the Expiratory Limb and Accessories
Pay particular attention to the expiratory side of the circuit.
Remove or replace, one item at a time:
- Bacterial or viral filters
- Heat-and-moisture exchangers
- Water traps
- Sampling adapters
- Flexible extensions
- Specialty airway connectors
A saturated filter or restricted accessory may allow inspiration while slowing exhalation.
Expected: Pressure falls promptly during expiration and stabilizes at the selected PEEP.
6. Inspect the Breathing-System Valves
With the machine removed from patient use, visually inspect the inspiratory and expiratory check-valve areas for:
- Moisture
- Debris
- A displaced valve disk
- A valve disk that does not move freely
- Incorrect assembly after cleaning
- Cracked or distorted visible components
Do not disassemble internal valve mechanisms beyond normal operator-removable components.
Expected: Visible valve disks are correctly seated and move freely during controlled testing.
If contamination or incorrect assembly is corrected, repeat the system checkout.
7. Inspect the Absorber and Breathing-System Assembly
Confirm that:
- The absorber canister is correctly installed.
- The breathing system is fully seated and latched.
- Removable components are installed in the correct orientation.
- No packing material, cleaning cap, or obstruction remains in the gas path.
- Excessive moisture or debris is not present.
- Seals and mating surfaces are clean and undamaged.
Expected: The breathing system is assembled correctly with no visible obstruction.
8. Check the Adjustable Pressure-Limiting Valve
If the issue occurs during manual or bag ventilation:
- Confirm that the bag/ventilator switch is fully in the intended position.
- Verify that the adjustable pressure-limiting valve rotates normally.
- Confirm that the valve is not set excessively high.
- Check for physical obstruction or contamination around accessible components.
Do not attempt internal repair of the valve mechanism during field troubleshooting.
Expected: Pressure releases appropriately during manual ventilation.
9. Evaluate the Scavenging System
Inspect the anesthetic-gas scavenging path for:
- Kinked evacuation tubing
- A blocked transfer hose
- A full or obstructed reservoir
- Excessive suction
- Incorrect scavenging connections
- A restricted wall-disposal connection
- Liquid accumulation in accessible condensate areas
Temporarily isolate the machine from the facility scavenging connection only in an approved test environment and according to facility procedures.
Expected: Scavenging does not create backpressure or interfere with breathing-system exhaust.
10. Check the Bellows Movement
Connect a verified test lung and observe the bellows during ventilation.
Look for:
- Incomplete bellows refill
- Hesitation during expiration
- Abnormal sticking
- Uneven movement
- Bellows failing to return fully
- Evidence of moisture or mechanical interference
The Avance uses an ascending bellows assembly, and abnormal filling or movement may indicate a breathing-system, exhaust, or ventilator problem.
Expected: The bellows moves smoothly and refills consistently between breaths.
Do not open the bellows housing or perform internal pneumatic adjustments outside authorized service procedures.
11. Compare Ventilator and Manual Modes
Test the machine with a test lung in both:
- Mechanical ventilation
- Manual or bag ventilation
Interpret the result:
- High pressure only during mechanical ventilation: Suspect settings, ventilator control, expiratory-flow control, or internal pneumatic operation.
- High pressure in both modes: Suspect the patient circuit, breathing system, check valves, APL valve, or scavenging path.
- High pressure only with one accessory installed: Replace that accessory.
Expected: The failure is narrowed to an external component, operating mode, or internal system.
12. Run the Approved System Checkout
After correcting external issues:
- Reassemble the breathing system.
- Install a known-good patient circuit and test lung.
- Run the normal pre-use or system checkout.
- Perform leak and ventilation testing.
- Verify selected and measured PEEP.
- Confirm that airway pressure returns to baseline between breaths.
- Confirm normal alarm operation.
Expected: The machine completes testing and maintains the selected PEEP without unintended pressure buildup.
If testing passes and the complaint cannot be reproduced, document all findings and return the device to service according to facility policy.
If the Problem Persists
If elevated expiratory pressure remains after settings, circuits, filters, check valves, absorber components, scavenging, and visible breathing-system components have been checked, common external causes have been ruled out.
The problem may involve an internal:
- Expiratory-flow control component
- PEEP-control valve
- Ventilator valve
- Pneumatic pathway
- Pressure sensor
- Breathing-system mechanism
- Electronic control fault
The device should be:
- Removed from service
- Labeled Out of Service
- Sent for authorized repair or bench evaluation
Do not continue clinical use based only on intermittent normal operation. Knowing when to stop and escalate is proper troubleshooting.
Clinical Use Tip
Never troubleshoot elevated PEEP on an active patient. Incomplete exhalation can cause unintended pressure buildup. Move the patient to verified equipment before manipulating circuits, valves, or scavenging connections.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Anesthesia staff reported that the GE Healthcare Avance displayed elevated PEEP and airway pressure did not return to the selected baseline during ventilation."
Cause
What was observed during troubleshooting.
Example:
"Testing found a moisture-saturated filter in the expiratory limb that restricted exhaled gas flow and caused pressure to remain elevated between breaths."
Resolution
What action was taken.
Example:
"Replaced the restricted filter, inspected the breathing circuit, completed the system checkout, and verified stable ventilation with measured PEEP matching the selected setting."
Helpful Details to Include (If Known)
- Selected and measured PEEP
- Ventilation mode and settings
- Airway-pressure waveform behavior
- Whether the issue occurred in ventilator or manual mode
- Patient circuit inspected or replaced
- Filters and accessories replaced
- Check-valve condition
- Bellows movement
- Scavenging connections checked
- Presence of moisture or obstruction
- System-checkout results
- Alarm messages recorded
- Final device status
Final Thought
Elevated expiratory pressure requires immediate attention because it may affect ventilation and patient safety. Start with settings, circuits, accessories, valves, and scavenging before suspecting internal failure. Escalate appropriately and document the complaint, confirmed cause, corrective action, and final operating status.
That is successful troubleshooting.