Drager Atlan A350

O2 Sensor Calibration or FiO2 Measurement Error

On this page

Asset Type

Anesthesia Machine

Manufacturer

Drager

Model

Atlan A350

What This Guide Helps With

Oxygen calibration fails or measured FiO2 is inaccurate because of gas supply, sampling, sensor, breathing-system, setup, or calibration-related problems.

Step-by-Step Troubleshooting

1. Protect the Patient and Verify Oxygen Delivery by an Alternate Method

If oxygen concentration is uncertain during clinical use, do not continue relying on the affected measurement. Maintain the patient on an appropriate verified anesthesia or ventilation system and independent oxygen monitoring as required. Expected outcome: Patient oxygen delivery is supported by reliable equipment while the affected machine is removed from clinical dependency.

2. Confirm the Reported O2 or FiO2 Problem

Record the exact calibration message, displayed FiO2, selected gas settings, ventilation condition, and whether the discrepancy occurs continuously or only during a particular test. Use approved independent oxygen-analysis equipment when available to confirm the discrepancy. Expected outcome: The reported oxygen measurement problem is objectively confirmed. If independent measurement agrees with the machine and no fault remains, complete final verification.

3. Verify the O2 Supply

Confirm the oxygen pipeline hose is connected properly and the associated supply is available. Inspect the hose and connectors for damage, looseness, or kinking. If a backup cylinder is part of the configuration, verify its condition according to facility practice. Expected outcome: The machine has a reliable external oxygen source. If restoring the supply resolves the calibration or measurement problem, repeat the applicable system test.

4. Inspect the Breathing and Sampling Paths

Check patient circuit connections, gas-sampling connections, filters, water traps where applicable, and other externally accessible components that may affect measured oxygen concentration. Look for leaks, disconnections, moisture, or incorrect setup. Expected outcome: The external breathing and measurement pathways are correctly assembled and free from obvious leakage or blockage. If correcting the setup restores accurate FiO2 measurement, proceed to final verification.

5. Inspect the O2 Sensor or Accessible Measurement Component

Where applicable to the installed configuration, inspect the accessible oxygen sensor or associated module for proper installation, secure connection, contamination, or obvious damage. Do not open internal sensor assemblies or alter service-level calibration values. Expected outcome: The sensor and accessible connections appear correctly installed and intact. If reseating an accessible component resolves the issue, repeat calibration.

6. Perform the Approved O2 Calibration

Place the machine in the required non-patient calibration condition and perform only the manufacturer-supported user or Clinical Engineering calibration procedure. Do not substitute improvised reference gases or alter protected parameters. Expected outcome: O2 calibration completes without error. If successful, verify measured oxygen concentration independently before returning the machine to service.

7. Compare FiO2 With Independent Test Equipment

Use an approved calibrated oxygen analyzer or anesthesia machine analyzer to compare delivered oxygen concentration with the Atlan A350 display under controlled conditions. Expected outcome: The machine's displayed oxygen concentration corresponds appropriately with independent measurement. If agreement is restored, troubleshooting can stop after complete functional testing.

8. Check for Intermittent Supply or Connection Problems

If the problem is intermittent, gently inspect accessible hoses and connectors without disrupting internal assemblies. Observe whether the error coincides with movement, a particular gas source, or an accessory configuration. Expected outcome: Intermittent external causes are identified or ruled out. If a defective external hose or connection is found, replace or correct it and repeat testing.

9. Perform Final Functional Verification

Complete the required system test, oxygen calibration, gas-delivery verification, ventilation test, and relevant alarm checks. Expected outcome: Oxygen delivery and displayed FiO2 are stable and independently verified, and all required system checks pass.

10. Escalate Unresolved Oxygen Measurement Problems

If calibration continues to fail or FiO2 remains inaccurate despite verified supply and external setup, remove the machine from service. Expected outcome: An anesthesia machine with unreliable oxygen measurement is not returned to patient care.

If the Problem Persists

Oxygen supply, external breathing and sampling paths, accessible sensor components, calibration procedure, and independent measurement have been evaluated. Remaining causes may involve the internal oxygen-measurement system, sensor interface, gas-mixing system, calibration circuitry, electronics, or another service-level condition. The device should be:

Following repair, independently verify oxygen concentration and complete all required system, gas-delivery, ventilation, alarm, and return-to-service testing. Knowing when to stop external troubleshooting is proper troubleshooting.

Clinical Use Tip

An uncertain FiO2 reading is a patient-safety issue even when the ventilator appears to be functioning normally.

Work Order Documentation (CCR Method)

CCR = Complaint, Cause, Resolution

Complaint

What was reported by the clinical staff.

Example:
"Anesthesia staff reported the Drager Atlan A350 displayed an FiO2 value inconsistent with the expected oxygen concentration during setup."

Cause

What was observed during troubleshooting.

Example:
"Clinical Engineering found the oxygen supply hose was not fully seated at the machine connection."

Resolution

What action was taken.

Example:
"Clinical Engineering secured the oxygen connection, completed the O2 calibration, confirmed oxygen concentration with approved test equipment, and returned the machine to service."

Helpful Details to Include (If Known)

Final Thought

Treat questionable oxygen measurement as a patient-safety concern, verify gas supply and external measurement conditions first, confirm performance independently, and escalate persistent inaccuracies appropriately. That is successful troubleshooting.

Related Guides

Was this guide helpful?

Don't see a guide you need?

Suggest a Guide