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What This Guide Helps With
Troubleshooting agent identification failure caused by sampling, gas flow, setup, contamination, or monitor faults.
Step-by-Step Troubleshooting
1. Ensure Patient Safety First
Before troubleshooting the Vamos 2, confirm the anesthesia provider has reliable gas and agent monitoring available.
Action:
- Verify the patient is being monitored safely.
- Confirm whether another anesthesia gas monitor, anesthesia machine gas module, or backup monitoring method is available.
- Do not interrupt active anesthetic monitoring unless the anesthesia provider confirms it is safe.
- If agent identification is unreliable during a case, notify anesthesia immediately.
Expected outcome: The patient remains safely monitored while the agent identification issue is evaluated.
Why it matters: Agent identification failure can affect anesthetic agent awareness, MAC display, inspired/expired agent values, and clinical decision-making.
If this resolves the concern by moving monitoring to a reliable device, stop and document the action.
2. Verify the Reported Failure
Confirm the exact symptom before replacing parts or removing the device.
Action:
- Check whether the Vamos 2 displays:
- Agent identification failure
- Agent not identified
- Incorrect agent
- No agent value
- Intermittent agent reading
- Observe whether CO2, N2O, O2, or other gas values are still displaying normally.
Expected outcome: The failure is confirmed as an agent identification issue, not a full gas sampling failure.
Why it matters: If all gas values are missing, the problem may be with sample flow, the sample line, the water trap, or the pump rather than only agent identification.
3. Check the Sample Line Connection
Inspect the sample line from the breathing circuit to the Vamos 2.
Action:
- Confirm the sample line is connected securely at both ends.
- Check for loose fittings, cracks, kinks, crushed tubing, or disconnection.
- Replace the sample line with a known-good line if damage or restriction is suspected.
Expected outcome: Sample gas reaches the monitor without leaks or restrictions.
If agent identification returns after correcting the sample line, stop and document the issue.
4. Check the Water Trap
Inspect the water trap or moisture collection point.
Action:
- Verify the water trap is properly seated.
- Check for moisture, secretions, contamination, or blockage.
- Replace the water trap if it appears wet, dirty, cracked, loose, or overdue for replacement.
Expected outcome: The sample path is dry, sealed, and unobstructed.
Why it matters: Moisture or contamination in the sample path can interfere with accurate gas and agent measurement.
If replacing or reseating the water trap restores agent identification, stop and document the correction.
5. Verify Sample Flow
Check whether the Vamos 2 appears to be pulling sample gas correctly.
Action:
- Look for sample flow alarms, occlusion messages, or weak/no sampling behavior.
- Listen for abnormal pump noise if normally audible.
- Confirm the sample line is not connected to a blocked filter, capped port, or incorrect connection point.
Expected outcome: The monitor has stable sample flow and no obvious occlusion.
If sample flow is not present or cannot be restored with external checks, remove the device from service.
6. Confirm the Anesthetic Agent Is Actually Present
Make sure the issue is not caused by the clinical setup.
Action:
- Ask anesthesia which agent is in use.
- Confirm the vaporizer is turned on only if clinically appropriate and verified by anesthesia.
- Confirm the monitor has had enough time to detect the agent after fresh gas flow begins.
- Do not adjust anesthesia machine settings yourself unless you are qualified and directed by anesthesia.
Expected outcome: The agent identification failure is not caused by absence of agent or a timing/setup issue.
Why it matters: Some monitors may need a stable sample before identifying the agent correctly.
7. Check for Mixed or Changing Agents
Agent identification may fail or become unreliable if multiple agents are present or the system is transitioning between agents.
Action:
- Ask whether the case recently switched agents.
- Ask whether the breathing circuit or anesthesia machine may contain residual agent from a previous case.
- Allow the monitor to observe a stable gas sample if clinically appropriate.
Expected outcome: The monitor identifies the agent once the sampled gas stabilizes.
If the issue clears after the agent concentration stabilizes, stop and document the finding.
8. Inspect for Contamination or Unusual Odor
Check for evidence of contamination around the sample system.
Action:
- Inspect the sample line, trap, fittings, and monitor inlet.
- Look for liquid, residue, discoloration, chemical odor, or visible contamination.
- Do not continue using a contaminated monitor on a patient.
Expected outcome: The external sampling path is clean and safe to use.
If contamination is found, remove the device from service for cleaning, evaluation, and possible repair.
9. Power Cycle Only When Safe
If the device is not being used for active patient monitoring, perform a controlled restart.
Action:
- Confirm with anesthesia that the device can be safely restarted.
- Power the Vamos 2 off.
- Wait briefly, then power it back on.
- Allow the device to complete startup and self-check.
- Reconnect the sample line and observe whether agent identification returns.
Expected outcome: A temporary software or startup recognition issue clears.
If the issue returns after restart, continue troubleshooting.
10. Compare Against a Known-Good Monitor
If available, compare the Vamos 2 to another anesthesia gas monitor or gas module.
Action:
- Use the same clinical setup only if safe and approved by anesthesia.
- Confirm whether the other monitor identifies the agent correctly.
- If the known-good monitor works with the same sample setup, suspect the Vamos 2.
Expected outcome: The issue is isolated to either the external sampling setup or the Vamos 2 itself.
Why it matters: A known-good comparison helps avoid unnecessary repair when the problem is actually the sample line, water trap, or anesthesia setup.
11. Check Date, Service Status, and Calibration/PM History
Review the device’s maintenance status.
Action:
- Check whether the Vamos 2 is overdue for PM, gas calibration, or manufacturer-recommended service.
- Review recent work orders for repeat agent identification complaints.
- Confirm whether the failure is recurring across multiple rooms or cases.
Expected outcome: Repeat or overdue-service issues are identified before returning the monitor to use.
If the monitor is overdue or has repeated failures, remove it from service for bench evaluation.
If the Problem Persists
If the sample line, water trap, connections, sampling path, clinical setup, and restart have been checked and the agent identification failure remains, common external causes have been ruled out.
The issue may involve the internal gas bench, infrared measurement system, sampling pump, internal contamination, software fault, or calibration/service need.
The device should be:
- Removed from service
- Labeled Out of Service
- Sent for repair, bench evaluation, gas bench testing, or vendor service as appropriate
Knowing when to stop is proper troubleshooting. Do not attempt internal gas bench repair or deep disassembly during clinical troubleshooting.
Clinical Use Tip
Do not troubleshoot agent identification failure on an active patient unless anesthesia confirms monitoring remains safe. If agent identification is needed for the case and the Vamos 2 cannot provide reliable values, move monitoring to another verified gas monitor before continuing troubleshooting.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Anesthesia reported that the Drager Vamos 2 failed to identify the anesthetic agent during use."
Cause
What was observed during troubleshooting.
Example:
"Found the water trap not fully seated, causing unreliable sample flow and intermittent agent identification."
Resolution
What action was taken.
Example:
"Reseated the water trap, replaced the sample line, verified stable sample flow, and confirmed agent identification returned during functional check."
Helpful Details to Include (If Known)
- Outlet tested if power concerns were involved
- Sample line inspected or replaced
- Water trap condition and seating checked
- Any sample flow or occlusion messages observed
- Whether CO2 and other gas values were present
- Agent being used, if provided by anesthesia
- Whether the issue was intermittent or constant
- Whether another monitor identified the agent correctly
- Any unusual odor, moisture, residue, or contamination
- PM/calibration status
- Final device status: returned to service or removed from service
Final Thought
Agent identification problems should be approached logically from the outside in. Protect the patient first, verify the complaint, check the sample path, confirm the clinical setup, and escalate when the problem points toward the internal gas bench or calibration system. Clear CCR documentation helps show what was ruled out and why the device was either returned to service or removed for repair.
That is successful troubleshooting.