Hamilton C6

High Pressure Alarm

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Asset Type

Ventilator

Manufacturer

Hamilton

Model

C6

What This Guide Helps With

Troubleshooting high-pressure alarms caused by circuit obstruction, flow-sensor tubing, expiratory components, accessories, alarm settings, or an internal ventilator fault.

Step-by-Step Troubleshooting

1. Ensure Patient Safety First

Do not troubleshoot a persistent high-pressure alarm while the HAMILTON-C6 is actively supporting a patient.

Notify respiratory therapy and the clinical team. Transfer the patient to another verified ventilator or approved ventilation method before continuing. Provide manual ventilation when clinically necessary and performed by qualified personnel.

Expected outcome: The patient is safely supported without relying on a ventilator that may be limiting or interrupting delivered breaths.

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

2. Confirm the Exact Alarm

Review the active alarm and alarm buffer. Determine whether the displayed message is:

Record the measured peak pressure, selected mode, PEEP, pressure settings, alarm limit, and whether the alarm occurs continuously or only during specific breaths.

On the HAMILTON-C6, the High pressure alarm occurs when measured inspiratory pressure exceeds the configured high Pressure alarm limit. The ventilator then stops inspiratory flow and opens the expiratory valve to reduce pressure.

Expected outcome: The exact alarm condition and circumstances are documented before equipment is changed.

3. Inspect the Patient Circuit for Kinks or Compression

Examine the entire breathing circuit from the ventilator ports to the test lung or patient connection.

Check for:

Correct any visible restriction and retest.

Expected outcome: The circuit remains fully open throughout inspiration and expiration.

If the alarm clears and pressure remains stable during testing, the obstruction was the likely cause. Stop troubleshooting.

4. Inspect the Artificial-Airway Connection or Test Setup

When testing off the patient, inspect the test lung, airway adapter, elbow, catheter mount, and all connecting fittings.

Verify that:

Hamilton specifically identifies artificial-airway kinks or occlusions as possible causes of a High pressure alarm.

Expected outcome: Gas can move freely through the complete test setup.

If replacing the test lung or adapter resolves the alarm, stop troubleshooting.

5. Check the Flow Sensor and Flow-Sensor Tubes

Inspect the flow sensor for contamination, incorrect installation, retained moisture, physical damage, or reversed orientation.

Check both flow-sensor tubes for:

Reseat the connections. Replace the flow sensor and tubing with known-good compatible components when available, then perform the required calibration or preoperational check.

Hamilton includes obstructed breathing-circuit limbs and flow-sensor tubes among the corrective checks for high-pressure conditions.

Expected outcome: The flow sensor is correctly installed, unobstructed, calibrated, and producing stable measurements.

If a known-good sensor assembly resolves the alarm, stop troubleshooting.

6. Inspect Filters, Humidifier, and Inline Accessories

Check every component placed in the gas pathway, including:

Look for saturation, contamination, incorrect assembly, retained water, or excessive resistance. Temporarily replace questionable components with known-good compatible accessories.

Do not operate the ventilator clinically with required filters or safety components removed.

Expected outcome: All inline components are correctly installed and allow unrestricted gas flow.

If replacing an obstructed filter or accessory resolves the alarm, stop troubleshooting.

7. Inspect the Expiratory Limb and Expiratory Valve Set

Check the expiratory limb for kinks, water accumulation, contamination, and blocked fittings.

Remove and visually inspect the user-removable expiratory valve set according to facility procedures. Verify that it is:

Install a known-good compatible expiratory valve set when available.

Expected outcome: Exhaled gas passes through the expiratory pathway without abnormal resistance.

If the alarm clears with a known-good expiratory valve set, stop troubleshooting.

8. Verify the Circuit Configuration and Patient Group

Confirm that the installed circuit, flow sensor, expiratory components, and test lung match the selected Adult/Pediatric or Neonatal patient group.

Check whether the issue began after:

Correct any mismatch and repeat the preoperational test.

Expected outcome: The physical circuit and configured patient group agree.

If correcting the configuration resolves the alarm, stop troubleshooting.

9. Review the High Pressure Alarm Limit and Plimit

Compare the high Pressure alarm limit with the selected ventilation settings and observed test-lung pressures.

Do not simply raise the alarm limit to silence an unexplained alarm. Confirm with respiratory therapy that the limit is clinically appropriate.

On the HAMILTON-C6, the high Pressure alarm limit and Plimit are linked; the high Pressure alarm limit is maintained 10 cmH₂O above Plimit.

If the alarm occurs only during the Sigh function, verify whether the message is High pressure during sigh. Hamilton recommends checking the circuit and airway for obstruction and considering disabling Sigh when clinically appropriate.

Expected outcome: Pressure settings and alarm limits are appropriate and are not creating a predictable nuisance alarm.

If an approved settings correction resolves the alarm, stop troubleshooting.

10. Test With a Known-Good Circuit and Test Lung

Install a complete known-good compatible breathing circuit, flow sensor, expiratory valve set, filters, and test lung.

Run the applicable preoperational check and ventilate the test lung using controlled settings. Observe:

Expected outcome: The ventilator operates normally with a verified external setup.

If the ventilator passes with the known-good setup, the original circuit or accessory assembly was the likely cause. Remove the defective component from use and stop troubleshooting.

11. Evaluate for a Ventilator-Side Fault

If the High pressure alarm continues with a verified circuit, flow sensor, expiratory valve, test lung, and appropriate settings, repeat the manufacturer-supported preoperational tests.

Watch for:

Hamilton states that the ventilator may enter the Ambient state when pressure remains substantially above the high Pressure alarm limit. Alternative ventilation is required if this occurs.

Expected outcome: A reproducible ventilator-side malfunction is identified without internal disassembly.

Do not proceed with internal pneumatic, valve, turbine, or pressure-transducer repair unless authorized, trained, and following current Hamilton service documentation.

If the Problem Persists

If the High pressure alarm remains after the breathing circuit, flow sensor, filters, accessories, expiratory valve set, test lung, patient-group selection, and alarm settings have been verified, common external causes have been ruled out.

The fault may involve the internal pressure-measurement system, inspiratory valve, expiratory-valve control, pneumatic pathway, turbine control, or related electronics.

The ventilator should be:

Knowing when to stop and escalate is proper troubleshooting.

Clinical Use Tip

Never troubleshoot a persistent high-pressure condition on an active patient. Move the patient to another verified ventilator before manipulating the circuit, flow sensor, expiratory valve, or pressure settings.

Maintain therapy continuity by confirming that the backup ventilator or approved ventilation method is operating correctly before removing the affected ventilator from clinical use.

Work Order Documentation (CCR Method)

CCR = Complaint, Cause, Resolution

Complaint

What was reported by the clinical staff.

Example:
"Respiratory therapy reported repeated High pressure alarms on the Hamilton C6 during ventilation."

Cause

What was observed during troubleshooting.

Example:
"Testing found a saturated expiratory filter restricting exhaled flow and causing peak pressure to exceed the configured alarm limit."

Resolution

What action was taken.

Example:
"Replaced the expiratory filter, installed a verified breathing circuit, completed the preoperational check, and confirmed stable ventilation without recurring alarms."

Helpful Details to Include (If Known)

Final Thought

High-pressure alarms require a patient-safety-first response and a logical inspection of every external gas pathway. Confirm the alarm, eliminate circuit resistance, verify settings, and escalate when the fault remains internal. Clear CCR documentation preserves both safety and service history.

That is successful troubleshooting.

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