On this page
Asset Type
Manufacturer
Model
What This Guide Helps With
Troubleshooting failed leakage tests or excessive breathing-system leakage caused by loose circuits, absorbers, sampling components, vaporizers, seals, or incorrect assembly.
Step-by-Step Troubleshooting
1. Ensure Patient Safety First
Do not perform a system test, leakage test, or extended troubleshooting while a patient is connected to the anesthesia machine.
If a leak is suspected during a procedure:
- Move ventilation to another verified anesthesia machine or approved backup method.
- Follow the facility’s anesthesia emergency procedures.
- Remove the affected Perseus from clinical reliance once patient care is stabilized.
Expected: Patient ventilation and anesthetic delivery are maintained using verified equipment.
The Perseus pressurizes the breathing system during testing, and the manufacturer specifically warns not to perform the system test with a patient connected.
2. Confirm the Exact Failure
Review the test screen and determine whether the reported problem is:
- Complete system-test failure
- Breathing-system test failure
- Leakage-test failure
- Excessive displayed leakage
- A leak that occurs only with a specific circuit or vaporizer installed
- A failure that began after cleaning, accessory replacement, or absorber replacement
Record any displayed test details, affected subsystem, leakage value, and color-coded result.
Expected: The complaint is narrowed to a repeatable test condition rather than a general report that the machine “leaks.”
3. Confirm the Device Is Prepared Exactly as Directed
Place the Perseus in Standby and prepare it according to the on-screen checklist.
Verify:
- No patient is connected.
- The circuit plug is installed where directed.
- Flexible hoses are extended to their intended working length.
- Required gas supplies are available.
- The breathing bag and breathing circuit are configured as shown on the screen.
- No test step has been skipped or accepted without correction.
Repeat the applicable automatic test.
Expected: The test completes successfully when the machine is configured correctly.
If the test passes, document the configuration error and stop troubleshooting.
4. Inspect the Breathing Circuit and Patient Connections
Check the inspiratory and expiratory hoses, Y-piece, filters, adapters, test plug, and breathing bag.
Look for:
- Loose or partially seated connections
- Cracked, stretched, punctured, or crushed hoses
- Damaged Y-piece or circuit plug
- Incorrectly installed filters or adapters
- A leaking or improperly connected breathing bag
- Incompatible or recently substituted accessories
Reseat each connection firmly. Replace questionable disposable components with verified compatible items, then repeat the leakage test.
Expected: Leakage decreases and the test passes after a defective or poorly seated circuit component is corrected.
5. Check the CO2 Absorber Assembly
Inspect the CO2 absorber or CLIC absorber assembly.
Verify:
- The absorber is fully inserted and locked.
- The absorber container is properly closed.
- The CLIC adapter is securely attached.
- No sealing surface is visibly dirty, folded, damaged, or obstructed.
- The absorber was assembled correctly after filling or replacement.
The manufacturer identifies an improperly secured absorber or CLIC adapter as a possible leakage source.
Repeat the leakage test after reseating or replacing the absorber assembly.
Expected: The test passes when the absorber and its sealing surfaces are correctly seated.
6. Inspect the APL Valve and Breathing-Bag Connection
Verify that the APL valve is correctly installed, securely seated, and positioned as required by the on-screen test instructions.
Inspect the breathing-bag connection, bag elbow, and optional flexible bag arm.
Check for:
- Loose threaded or push-fit connections
- Incorrectly seated flexible arm
- Damaged bag-arm sealing ring
- Cracked elbow or connector
- APL valve that was incorrectly reinstalled after cleaning
Do not disassemble the valve internally. Correct only external fitment or replace a visibly damaged approved component.
Expected: The leak test passes after the APL valve or bag assembly is correctly seated.
7. Check the Water Trap and Sample Line
Inspect the gas-monitoring sampling path.
Verify:
- The water trap is installed and fully seated.
- The sample line is connected at both ends.
- The sample line is not kinked, split, loose, or leaking.
- Sample-line fittings are undamaged.
- The water trap is not cracked, overfilled, or incorrectly installed.
Replace the sample line or water trap with verified compatible components when damage is suspected.
Expected: The leakage test passes after the sampling system is restored to a sealed condition.
8. Inspect External Breathing-System Seating
If the failure began after cleaning or breathing-system replacement, verify that the removable breathing system is fully seated and locked into the machine.
Check externally that:
- The breathing-system housing is sitting flush.
- Locking levers are fully engaged.
- Inspiratory and expiratory ports are secure.
- Flow-sensor ports are properly seated.
- No visible O-ring is missing, pinched, contaminated, or displaced.
- The breathing-system cover does not prevent complete seating.
Do not proceed into internal pneumatic disassembly.
Expected: The test passes after correcting an incomplete installation or externally visible seal problem.
9. Isolate Vaporizers as a Possible Leak Source
Ensure each vaporizer is:
- Upright and fully seated on its mounting adapter
- Locked into position
- Set to the off or zero position
- Properly closed at its filling and draining connections
- Free from visible damage or leakage
Run the leakage test with the vaporizers configured as directed by the on-screen instructions. When appropriate and permitted by facility procedure, test one vaporizer at a time or remove a suspect vaporizer to determine whether the failure follows it.
The Perseus leakage assistant can support evaluation of breathing-system, circuit, and vaporizer leakage by continuously displaying test pressure and leakage changes.
Expected: The failure is isolated to a particular vaporizer or mounting position.
If the test passes without one vaporizer, remove that vaporizer from service for separate evaluation.
10. Use the Leakage Assistant
From the test details screen, open the Leakage Assistant and follow the displayed instructions.
While the system maintains test pressure:
- Gently reseat one external connection at a time.
- Watch for a meaningful change in the displayed leakage value.
- Avoid changing several components simultaneously.
- Repeat the component test after correcting the suspected source.
The manufacturer recommends systematic leak localization by isolating individual components and using the leakage assistant when needed.
Expected: A specific circuit, absorber, sampling component, vaporizer, or breathing-system connection is identified.
If the test passes, complete a full operational checkout before returning the machine to service.
If the Problem Persists
If the breathing circuit, bag, absorber, sampling components, vaporizer configuration, accessory connections, and external breathing-system seating have been verified, common external causes have been ruled out.
The remaining condition may involve an internal valve, pneumatic seal, flow-sensor seal, breathing-system housing defect, mounting interface, or another internal leakage source.
The device should be:
- Removed from service
- Labeled Out of Service
- Sent for qualified repair or bench evaluation
- Evaluated under the applicable manufacturer service procedure
Do not repeatedly accept a failed or restricted test result to keep the machine in service. Knowing when to stop external troubleshooting and escalate is proper Clinical Engineering practice.
Clinical Use Tip
Never troubleshoot a suspected anesthesia breathing-system leak on an active patient. Transfer ventilation and anesthetic delivery first, then test the affected machine in a controlled environment.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Anesthesia staff reported that the Drager Perseus failed its pre-use leakage test and displayed excessive breathing-system leakage."
Cause
What was observed during troubleshooting.
Example:
"Clinical Engineering found the CO2 absorber incompletely seated, preventing the absorber seal from closing properly."
Resolution
What action was taken.
Example:
"Reseated and locked the absorber, repeated the leakage and system tests successfully, completed an operational checkout, and returned the machine to service."
Helpful Details to Include (If Known)
- Patient connected when issue occurred: Yes / No
- Exact failed test and displayed leakage value
- Test result color or restriction message
- Breathing circuit and bag inspected
- Circuit or filter replaced
- CO2 absorber and CLIC adapter checked
- Water trap and sample line checked
- APL valve and bag arm checked
- Vaporizer configuration tested
- Leakage assistant findings
- Issue began after cleaning or accessory replacement
- Unusual gas odor, sound, heat, or visible damage
- Final system-test result
- Final device status
Final Thought
Breathing-system leak failures require a methodical approach because loose external components can imitate serious internal faults. Protect the patient first, isolate one component at a time, and escalate when the machine cannot pass its required testing. Accurate CCR documentation preserves both safety and service history.
That is successful troubleshooting.