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Asset Type
Sequential Compression Device (SCD)
Manufacturer
Model
What This Guide Helps With
Troubleshooting low pressure, leak alarms, loose tubing, damaged sleeves, poor sleeve fit, or pneumatic delivery issues on the Kendall SCD Express.
Step-by-Step Troubleshooting
Ensure Patient Safety First
Confirm the Kendall SCD Express is not being troubleshot while actively providing therapy to a patient without clinical approval.
If compression therapy is required, have nursing move the patient to another working SCD pump and sleeve set first.
Expected outcome: Patient DVT prevention therapy is maintained without relying on a device with an unresolved pressure alarm.
Confirm the Exact Alarm Complaint
Ask staff when the low pressure or leak alarm occurs.
Check whether the alarm happens:
- Immediately at startup
- Only on Port A
- Only on Port B
- Only with one sleeve
- After several compression cycles
- After the patient moves
- With both sleeves connected
Expected outcome: The issue is narrowed to the pump, tubing, sleeve, connection, or patient application.
Check the Sleeve Application
Inspect the compression sleeve while it is applied to the patient or wrapped around an approved test form.
Verify that the sleeve is wrapped securely, not loose, not twisted, and not partially open.
A loose or poorly fitted sleeve may prevent the system from building or holding pressure.
Expected outcome: The sleeve is properly fitted and able to inflate normally.
If correcting sleeve fit clears the alarm, return the device to service after confirming normal operation.
Inspect the Tubing Connections
Check the tubing connection at the controller and at the sleeve.
Make sure connectors are fully seated and not partially inserted.
Gently wiggle the connection while observing for loose fit, intermittent alarm behavior, or hissing.
Expected outcome: Tubing is firmly connected with no obvious leak at the ports.
If reseating the tubing clears the alarm, confirm several compression cycles before returning the unit to use.
Inspect the Tubing Set for Damage
Follow the tubing from the pump to the sleeve.
Look for:
- Cracks
- Kinks
- Pinched sections
- Split tubing
- Stretched connectors
- Missing or damaged fittings
- Tubing caught under a bed rail, mattress, or chair
Expected outcome: Tubing is intact and air can flow freely from the pump to the sleeve.
If damaged tubing is found, replace the tubing set and retest.
Swap the Tubing Set
Connect a known-good Kendall-compatible tubing set.
Run the pump with a known-good sleeve or test setup.
Expected outcome: If the alarm clears, the original tubing set was leaking or restricted.
If this resolves the issue, remove the defective tubing from use.
Swap the Sleeve
Connect a known-good sleeve to the same tubing and port.
Verify the sleeve type and size are appropriate for the application. Kendall SCD Express sleeves are part of the Kendall SCD compression system family and use pneumatic compression through compatible tubing and controller connections.
Expected outcome: If the alarm clears with a known-good sleeve, the original sleeve may have an air leak, poor connector fit, or damaged bladder.
If this resolves the issue, discard or remove the defective sleeve per facility policy.
Test One Port at a Time
If the unit has two connected sleeve ports, test each side separately using known-good tubing and sleeve components.
Check whether Port A or Port B consistently causes the low pressure alarm.
Expected outcome: The fault is isolated to one side or confirmed across both ports.
If one port fails repeatedly with known-good accessories, remove the controller from service.
Listen for Air Leaks During Inflation
During a safe test cycle, listen near the sleeve, tubing, connector, and controller port.
Do not place your face close to contaminated patient-use accessories.
Expected outcome: No audible hiss is heard during inflation or pressure hold.
If a hiss is heard from an accessory, replace that accessory and retest.
Check for Obvious Pump Output Issues
With known-good tubing and sleeve connected, observe whether the sleeve inflates normally.
Look for weak inflation, delayed inflation, repeated alarm cycling, or no inflation.
Expected outcome: The controller should inflate the sleeve consistently during compression cycles.
If the controller cannot inflate known-good accessories, suspect an internal pump, valve, sensor, or pneumatic leak.
Check Power and Battery Condition
Confirm the unit is connected to AC power if available.
Verify the power cord is secure and the unit is not cycling power, shutting down, or alarming due to low battery.
Expected outcome: The controller has stable power during pneumatic operation.
If unstable power is found, correct the power issue and retest.
Run Only Approved User-Level Tests
If your department’s procedure allows use of Kendall SCD Express test modes, perform only approved external leak or performance checks using proper test accessories.
The Kendall SCD Express service literature describes leak testing based on pressure decay; a significant pressure drop during the hold period can trigger a low pressure alarm.
Expected outcome: Leak testing helps confirm whether the issue is external tubing/sleeve related or internal to the controller.
Do not perform deep disassembly or internal pneumatic repair at the point of care.
Confirm Final Operation
After correcting any external issue, run the SCD with known-good sleeves and tubing long enough to verify stable inflation and no repeated low pressure alarm.
Expected outcome: The device completes normal compression cycles without leak or low pressure alarms.
If the alarm does not return, clean the device per facility policy and return it to service.
If the Problem Persists
If the Kendall SCD Express continues to show a low pressure or leak alarm after sleeve fit, tubing, connectors, accessories, port testing, and power have been checked, common external causes have been ruled out.
The device should be:
- Removed from service
- Labeled Out of Service
- Sent for repair or bench evaluation
At that point, the issue may involve an internal pump, valve, pressure sensor, manifold, internal tubing, or controller pneumatic leak. Knowing when to stop is proper troubleshooting, especially when compression therapy performance cannot be verified.
Clinical Use Tip
Do not troubleshoot a low pressure or leak alarm on an active patient if therapy is needed. Have nursing move the patient to another working SCD pump and sleeve set first, then evaluate the suspect unit safely.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Nursing reported that the Kendall SCD Express was alarming low pressure during patient use and the sleeve was not inflating consistently."
Cause
What was observed during troubleshooting.
Example:
"Found the Port A tubing connector partially seated and the right leg sleeve loosely wrapped, causing poor pressure hold during inflation."
Resolution
What action was taken.
Example:
"Reseated tubing, replaced the sleeve set, verified normal compression cycles on both ports, cleaned the unit, and returned it to service."
Helpful Details to Include (If Known)
- Whether the alarm occurred on Port A, Port B, or both
- Sleeve size and type used
- Tubing set condition
- Whether tubing was kinked, cracked, loose, or pinched
- Whether a known-good tubing set was tested
- Whether a known-good sleeve was tested
- Whether the alarm occurred immediately or after several cycles
- Audible air leak or hissing
- AC power or battery status
- Final device status: returned to service or removed for repair
Final Thought
Low pressure and leak alarms on an SCD should be approached logically. Start with the patient, sleeve fit, tubing, connectors, and accessories before suspecting the controller. If pressure cannot be verified with known-good external parts, remove the device from service and document the complaint, cause, and resolution clearly.
That is successful troubleshooting.