Smiths Medical CADD Legacy

Air-in-Line Alarm or Repeated False Air Detection

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Asset Type

Infusion Pump

Manufacturer

Smiths Medical

Model

CADD Legacy

What This Guide Helps With

Troubleshoots air-related alarms caused by actual air, tubing placement, disposable condition, contamination, positioning, or a suspected detection-system problem.

Step-by-Step Troubleshooting

1. Protect the Patient and Maintain Therapy

Do not troubleshoot an unreliable infusion pump while a patient depends on uninterrupted or accurately monitored therapy.

Transfer therapy to another verified pump when necessary and allow clinical staff to manage the patient line and medication according to policy.

Expected outcome: Patient therapy is safely maintained while the suspect pump is evaluated.

2. Confirm the Exact Alarm and History

Verify the exact alarm reported and determine whether clinical staff observed visible air in the tubing.

Ask whether the alarm occurs with every cassette or set, only in a particular orientation, or only after the device has been moved.

Expected outcome: The reported air-detection condition is accurately characterized.

3. Inspect the Administration Set for Actual Air

Examine the external tubing and cassette for visible bubbles, incomplete priming, an empty source container, loose connections, or other conditions that could introduce air.

Clinical staff should correct or replace the patient fluid path according to clinical policy. Clinical Engineering should not defeat an air alarm to continue patient therapy.

Expected outcome: The fluid path contains no visible unintended air before further pump testing.

4. Inspect Tubing and Disposable Placement

Verify that the compatible administration set or cassette is correctly installed and that tubing passes through any externally accessible sensing area as intended.

Look for:

Clean accessible surfaces only using approved procedures.

Expected outcome: The disposable and tubing are correctly positioned and free of visible damage or contamination.

5. Test With a Known-Good Disposable

If false detection is suspected, install a compatible known-good set or cassette prepared for bench testing.

Do not use a questionable or previously contaminated disposable.

Expected outcome: The pump operates normally with the known-good disposable. If the problem follows the original disposable, replace it and stop troubleshooting after successful verification.

6. Check Pump Position and Environment

Operate the pump in its normal orientation and confirm that the tubing is not shifting, pulling, or separating from the intended sensing location during movement.

Inspect for obvious moisture, residue, or physical damage around accessible areas of the pump.

Expected outcome: Normal positioning and handling do not produce an inappropriate air alarm.

7. Perform Functional Alarm Verification

Using approved test methods and suitable equipment, verify that the pump operates normally under an air-free condition and responds appropriately during required alarm testing.

Do not bypass or desensitize the air-detection system.

Expected outcome: The pump does not generate false alarms during normal testing and required alarm functions remain operational.

8. Determine Return-to-Service Status

If correct tubing placement, an air-free known-good disposable, and normal positioning eliminate the issue, complete required return-to-service testing.

If unexplained air-in-line alarms recur, remove the device from service.

Expected outcome: The pump either passes final testing or is escalated for service.

If the Problem Persists

After actual air, disposable condition, tubing placement, contamination, and positioning have been ruled out, the problem may involve the air-detection system, mechanical alignment, electronic sensing, configuration, or another service-level condition.

The device should be:

Complete appropriate alarm, delivery, operational, and safety verification after any repair.

Knowing when external causes have been exhausted and escalation is required is proper troubleshooting.

Clinical Use Tip

Never bypass an air-related alarm to keep therapy running; provide another verified infusion device while the cause is evaluated.

Work Order Documentation (CCR Method)

CCR = Complaint, Cause, Resolution

Complaint

What was reported by the clinical staff.

Example:
"Nursing reported repeated air-in-line alarms even though no visible air was seen in the tubing."

Cause

What was observed during troubleshooting.

Example:
"Clinical Engineering found the disposable tubing improperly positioned at the pump and confirmed normal operation after correct installation."

Resolution

What action was taken.

Example:
"The disposable was reinstalled correctly, the pump was tested with an air-free fluid path, and no false alarms recurred."

Helpful Details to Include (If Known)

Final Thought

Air alarms require a patient-safety-first response. Verify actual air, tubing placement, disposable integrity, and normal operating conditions before suspecting an internal sensing problem, then escalate when reliable operation cannot be demonstrated.

That is successful troubleshooting.

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