Puritan Bennett 980

High Airway Pressure Alarm

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Asset Type

Ventilator

Manufacturer

Puritan Bennett

Model

980

What This Guide Helps With

Troubleshooting high circuit pressure alarms caused by circuit restrictions, condensation, filters, accessories, alarm settings, test-lung setup, or internal pressure-control faults.

Step-by-Step Troubleshooting

1. Ensure Patient Safety First

Do not troubleshoot a high airway pressure alarm while the Puritan Bennett 980 is actively supporting a patient.

Expected outcome: The patient is safely supported without relying on the affected ventilator.

Continue Clinical Engineering troubleshooting only after the PB980 has been removed from patient use.

2. Confirm the Exact Alarm

Review the active alarm banner and alarm log. Confirm whether the displayed condition is:

Record the displayed peak pressure, alarm limit, ventilation mode, and whether inspiration is being terminated early.

The PB980 high circuit pressure alarm occurs when measured airway pressure reaches or exceeds the configured high-pressure limit. When triggered, the ventilator ends inspiration and transitions to exhalation.

Expected outcome: The reported issue is confirmed as a high circuit pressure condition rather than a different ventilator alarm.

3. Inspect the Breathing Circuit for Obstruction

With the ventilator disconnected from the patient, inspect the entire inspiratory and expiratory circuit.

Check for:

Straighten or replace any restricted component.

Expected outcome: The circuit is open, correctly assembled, and free of visible restrictions.

If the alarm clears after correcting the circuit, complete functional testing and stop.

4. Check for Condensation or Fluid Accumulation

Inspect the circuit, water traps, humidifier chamber, filters, and expiratory limb for pooled condensate.

Do not drain condensate toward the ventilator or patient connection.

Expected outcome: Gas can move freely through both circuit limbs without fluid-related restriction.

If the alarm no longer occurs, complete functional testing and stop.

5. Inspect the Inspiratory and Expiratory Filters

Check installed filters for:

Replace suspect filters with approved, compatible components.

Expected outcome: Both filters are dry, correctly installed, and do not create excessive flow resistance.

If filter replacement resolves the alarm, document the finding and stop.

6. Inspect the Expiratory Filter and Exhalation Assembly Connection

Confirm that the expiratory filter is fully seated and that the exhalation assembly area is clean and unobstructed externally.

Expected outcome: The expiratory pathway is correctly connected and externally unobstructed.

If correcting the connection resolves the issue, complete testing and stop.

7. Remove Nonessential Circuit Accessories

Temporarily remove or replace externally installed accessories that may increase resistance, including:

Reassemble the circuit using the minimum approved configuration for bench testing.

Expected outcome: The alarm does not recur when a restrictive or incorrectly installed accessory is removed.

If one accessory causes the condition, replace it and stop.

8. Verify Circuit Type and Patient Setup

Confirm that the installed circuit and patient category match the ventilator setup.

Review:

An incorrect circuit configuration can affect pressure measurement, compensation, and alarm behavior.

Expected outcome: The physical circuit matches the selected patient and humidification configuration.

If correcting the setup resolves the alarm, repeat the required circuit test and stop.

9. Review the High-Pressure Alarm Limit

Have respiratory therapy or other authorized clinical personnel verify that the high circuit pressure limit is appropriate for the intended test settings.

Do not raise an alarm limit solely to silence an unexplained alarm.

The PB980 pressure limit remains active during normal ventilation modes and cannot be disabled.

Expected outcome: The alarm limit is clinically appropriate and not inadvertently set below the expected peak pressure.

If an incorrect setting caused the alarm, correct it, verify operation, and stop.

10. Review Ventilation Settings for Pressure Overshoot

Using an approved test lung, review the programmed settings with qualified respiratory therapy personnel.

Check for combinations that may produce excessive peak pressure, such as:

The PB980 may allow brief pressure overshoot during the initial portion of pressure-control or pressure-support breaths, particularly with aggressive rise-time settings.

Expected outcome: Peak pressure remains below the alarm limit when appropriate settings and a suitable test lung are used.

If correcting the settings resolves the problem, perform final verification and stop.

11. Substitute a Known-Good Circuit and Test Lung

Install a complete known-good compatible circuit, filters, and test lung.

Expected outcome: The alarm does not recur with the known-good circuit.

If the alarm clears, the original circuit or accessory set was the likely cause. Replace the defective component and stop.

12. Perform the Required Short Self-Test

Run the manufacturer-required short self-test using the approved test setup whenever the circuit has been replaced or the integrity of the breathing system is uncertain.

Do not return the ventilator to service if:

Expected outcome: The PB980 completes testing successfully without pressure-system or circuit faults.

If the test passes and the alarm cannot be reproduced, complete a full operational verification before returning the device to service.

13. Check for Reproducible Pressure-Sensing or Control Error

With a known-good circuit and test lung, determine whether the displayed pressure is reasonable compared with the selected settings and an independent calibrated analyzer, when available.

Remove the ventilator from service if:

Expected outcome: Pressure delivery and displayed pressure agree within the applicable performance limits.

An abnormal result suggests an internal pressure sensor, valve, exhalation-control, or pneumatic-control problem.

If the Problem Persists

If the high airway pressure alarm continues after the circuit, filters, condensate, accessories, setup, alarm limit, test lung, and external connections have been verified, common external causes have been ruled out.

The ventilator should be:

Do not attempt internal pneumatic, valve, sensor, or board-level repair unless properly trained and authorized.

Knowing when to stop external troubleshooting and escalate the device is proper Clinical Engineering practice.

Clinical Use Tip

Never troubleshoot recurrent high airway pressure alarms on an active patient. Transfer the patient first, because the alarm may indicate a genuine airway obstruction, reduced lung compliance, circuit occlusion, or equipment malfunction.

Work Order Documentation (CCR Method)

CCR = Complaint, Cause, Resolution

Complaint

What was reported by the clinical staff.

Example:
"Respiratory therapy reported repeated HIGH CIRCUIT PRESSURE alarms on a Puritan Bennett 980 during ventilation."

Cause

What was observed during troubleshooting.

Example:
"Inspection found the expiratory filter saturated with condensate, creating excessive resistance and elevated circuit pressure."

Resolution

What action was taken.

Example:
"Removed the ventilator from service, replaced the expiratory filter and circuit, completed the short self-test and operational verification, and returned the unit to service after all tests passed."

Helpful Details to Include (If Known)

Final Thought

High airway pressure alarms require a safety-first and logic-based approach. Verify genuine clinical causes, then inspect the circuit, filters, accessories, settings, and test setup before suspecting internal failure. Proper escalation and complete CCR documentation protect both the patient and the reliability of the ventilator fleet.

That is successful troubleshooting.

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