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What This Guide Helps With
This guide addresses situations where the Mindray WATO EX Series anesthesia machine:
- Triggers ventilator alarms (e.g., “No Volume Delivery,” “Low Tidal Volume”)
- Fails to deliver set tidal volumes to the patient
- Shows abnormal pressure or flow readings
The focus is on external, easily verifiable causes first, ensuring patient safety and avoiding unnecessary internal repairs.
Step-by-Step Troubleshooting
Verify Power and Startup
- Ensure the machine is connected to a reliable power source and switched on.
- Check that the battery (if applicable) is charged and the backup battery is functional.
- Why: Insufficient power can prevent the ventilator from delivering volume even if settings appear correct.
Check Gas Supply
- Confirm that oxygen and air pipelines are connected and supplying correct pressures.
- Check pipeline pressure indicators on the machine.
- Why: Ventilator volume delivery requires proper gas supply; alarms often occur if pressures are too low.
Inspect the Breathing Circuit
- Check for disconnections, kinks, or leaks in the inspiratory and expiratory limbs.
- Ensure the circuit is properly assembled and all valves are seated correctly.
- Why: Leaks or disconnections can prevent the set tidal volume from reaching the patient.
Check Patient Valve and Filters
- Inspect the patient valve for obstruction or improper installation.
- Replace filters if clogged or saturated.
- Why: Blocked valves or filters increase resistance, reducing delivered volume.
Verify Ventilator Settings
- Confirm correct mode, tidal volume, respiratory rate, and inspiratory pressure.
- Ensure that any patient-specific alarms or safety limits are not preventing delivery.
- Why: Incorrect settings or active safety limits can inhibit ventilation.
Observe Alarms and Indicators
- Note any specific alarm codes or messages.
- Refer to the Mindray quick reference card for external checks related to the alarms.
- Why: Alarm codes often indicate whether the cause is mechanical, flow-related, or sensor-based.
If the Problem Persists
If all external checks have been completed and the ventilator still fails to deliver volume:
- Remove the anesthesia machine from service.
- Label the machine “Out of Service” to prevent patient use.
- Escalate for bench evaluation or service by qualified Biomedical Engineering or Mindray service personnel.
Note: Knowing when to stop is proper troubleshooting and ensures patient safety.
Clinical Use Tip
- Never attempt troubleshooting on a patient actively connected to the ventilator.
- Move the patient to a backup ventilator before performing any checks.
- Only troubleshoot when the patient is safely supported by an alternative device.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
“User reports ventilator alarm “No Volume Delivery” and patient is not receiving set tidal volume.”
Cause
What was observed during troubleshooting.
Example:
“Upon inspection, all power, gas supply, circuit connections, and ventilator settings were verified. No external issues found; machine fails to deliver volume.”
Resolution
What action was taken.
Example:
“Machine removed from service, labeled Out of Service, and sent for service/repair.”
Helpful Details to Include
- Gas pressures checked and within specification
- Circuit assembled correctly, no kinks or disconnections
- Filters and patient valve checked
- Alarm codes recorded
- Machine status and settings noted prior to removal
Final Thought
Always prioritize patient safety, follow logic-based troubleshooting, and escalate when external factors are ruled out. Proper documentation ensures continuity of care and supports service decisions.
That is successful troubleshooting.