Baxter PrismaFlex

Asset Type

Continuous Renal Replacement Therapy (CRRT)

Manufacturer

Baxter

Model

PrismaFlex

What This Guide Helps With

This guide helps troubleshoot the Baxter PrismaFlex Filter Extremely Positive alarm. This alarm may occur when filter pressure reaches or exceeds 450 mmHg and can be associated with restricted blood flow, filter clotting, high return pressure, catheter issues, tubing restriction, or pressure-sensing failure.

The alarm should be treated as a potentially serious CRRT pressure condition because excessive filter pressure can affect therapy delivery, circuit safety, and patient care.

Step-by-Step Troubleshooting

1. Ensure Patient Safety First

• Confirm the patient is stable and that clinical staff are aware the PrismaFlex is alarming.
• Do not troubleshoot the circuit in a way that interrupts therapy without nursing or provider involvement.
• If the circuit appears clotted, pressure is excessive, or blood return is unsafe, follow facility CRRT policy and clinical direction.
• If therapy must continue, have clinical staff prepare a backup CRRT device or alternate therapy plan.

Expected outcome: Patient care is protected before device or circuit troubleshooting begins.

2. Verify the Reported Alarm and Behavior

• Confirm the displayed alarm is Filter Extremely Positive.
• Check whether filter pressure is at or above 450 mmHg.
• Document whether the alarm occurs immediately after treatment start or during therapy.
• Observe whether return pressure is also elevated.
• Check whether blood flow appears restricted.
• Look for visible clotting, circuit darkening, poor flow, or repeated pressure alarms.

Expected outcome: The alarm is confirmed and the pressure condition is clearly documented.

3. Translate the Alarm Into the Real-World Condition

• Understand that the PrismaFlex is detecting excessively high pressure at the filter pressure pod.
• Focus troubleshooting on restriction between the filter pressure pod and filter, restriction between the filter and deaeration chamber, filter clotting, high return pressure, catheter performance, and pressure sensing.
• Do not assume the machine has failed until external circuit and clinical causes have been checked.

Expected outcome: Troubleshooting stays focused on pressure, restriction, clotting, catheter performance, and sensing accuracy.

4. Check for Clamped or Kinked Lines

• Inspect the blood-flow path between the filter pressure pod and the filter.
• Inspect the line between the filter and the deaeration chamber.
• Look for closed clamps, partially closed clamps, kinked tubing, trapped tubing, twisted tubing, or tubing compressed by bedrails, blankets, patient movement, or nearby devices.
• Correct any obvious restriction found.

Expected outcome: Lines are open, routed correctly, and free of visible restriction.

5. Confirm Circuit Routing and Set Position

• Verify the disposable set is seated correctly in the PrismaFlex.
• Check that tubing is not pulled tight, misrouted, or pinched around the cassette, filter, pump area, or pressure pod.
• Confirm the filter pressure pod is properly positioned and not physically distorted.
• Check the pressure pod interface for contamination, poor seating, or visible damage.

Expected outcome: The set is installed correctly with no external compression or misrouting.

6. Check for High Return Pressure

• Review the return pressure reading and any related return-side alarms.
• If return pressure is high, coordinate with clinical staff to assess for return line restriction, return catheter issues, patient position affecting catheter flow, catheter clotting, poor patency, or excessive blood flow rate for the current access condition.
• Do not independently change therapy settings unless permitted by local Clinical Engineering policy and clinical workflow.

Expected outcome: Return pressure is understood as either normal or contributing to the filter pressure alarm.

7. Lower Blood Flow Rate if Clinically Appropriate

• If the alarm occurs while blood flow is high or return pressure is elevated, clinical staff may lower the blood flow rate according to facility policy and provider direction.
• Confirm that any setting change is performed by authorized clinical staff.
• Monitor whether filter pressure decreases after the change.

Expected outcome: Reduced blood flow may reduce pressure enough to continue safe therapy if the circuit and access are otherwise acceptable.

8. Inspect for Developing Filter Clotting

• Ask clinical staff whether the filter has shown signs of clotting or reduced performance.
• Look for dark streaking in the filter, visible clot formation, increasing transmembrane pressure trends, repeated pressure alarms, poor flow, or rising filter pressure over time.
• If clotting is suspected, follow clinical and facility procedure for set change or therapy interruption.

Expected outcome: Filter condition is assessed before assuming a machine failure.

9. Relieve Excess Pressure if the System Allows

• If the PrismaFlex displays an available option such as RELEASE CLAMP, have the operator follow the on-screen prompt and facility procedure.
• Observe whether the pressure decreases and whether the alarm clears.
• Do not bypass or ignore on-screen safety instructions.

Expected outcome: Excess pressure is relieved and the alarm clears without recurring.

10. Stop When Resolved

• If the alarm clears after correcting a clamp, kink, tubing restriction, catheter issue, or high-pressure condition, confirm pressures remain stable.
• Confirm no related pressure alarms return.
• Verify blood flow appears appropriate.
• Document the correction and allow clinical staff to continue therapy per facility policy.

Expected outcome: The PrismaFlex remains in service with stable pressures and no recurring Filter Extremely Positive alarm.

11. Change the Set if Operator Correction Does Not Clear the Alarm

• If the alarm does not clear, returns immediately, or the filter appears clotted, the set should be changed using STOP according to operator procedure and facility policy.
• Clinical staff should determine whether blood can be safely returned or whether the circuit must be discarded.
• Do not continue therapy with excessive filter pressure or a suspected clotted filter.

Expected outcome: Therapy is restarted only with a safe, functional circuit.

12. Evaluate for Repeated Alarms After Circuit Correction

• If repeated Filter Extremely Positive alarms occur despite proper tubing, catheter function, flow settings, and a new set, evaluate the machine side.
• Check the filter pressure pod interface, pressure sensor area, pressure pod seating, ARPS circuit condition, and history of similar pressure-sensing alarms.
• Compare reported pressure readings with the visible circuit condition to identify unrealistic or inconsistent pressure values.

Expected outcome: Repeated alarms are narrowed toward device pressure sensing rather than disposable set or access problems.

13. Perform Bench Evaluation if Device Failure Is Suspected

• Remove the PrismaFlex from clinical use if repeated alarms suggest pressure-sensing failure.
• During bench evaluation, check the filter pressure sensor pathway and ARPS-related function per service procedure.
• Calibrate the filter pressure sensor if indicated and authorized.
• Replace the pressure sensor or related sensing component if calibration fails or readings remain inaccurate.

Expected outcome: Pressure sensing is verified before the device is returned to service.

If the Problem Persists

If external restrictions, clamps, tubing kinks, catheter issues, blood flow settings, excessive pressure, and circuit clotting have been ruled out, persistent Filter Extremely Positive alarms strongly suggest a pressure-sensing or internal device problem.

Remove the PrismaFlex from service, label it Out of Service, and send it for repair or bench evaluation.

Knowing when to stop is proper troubleshooting.

Clinical Use Tip

Never troubleshoot on an active patient. Move the patient to a backup device first when therapy cannot safely continue on the alarming PrismaFlex.

Coordinate with nursing and the provider before changing flow conditions, stopping therapy, releasing pressure, returning blood, or changing the set. Avoid relying on a PrismaFlex with repeated unresolved pressure alarms.

Work Order Documentation (CCR Method)

CCR = Complaint, Cause, Resolution

Complaint

What was reported by the clinical staff.

Example:
"PrismaFlex reported Filter Extremely Positive alarm during CRRT. Filter pressure reached or exceeded 450 mmHg. Staff reported repeated pressure alarms and concern for restricted blood flow or filter clotting."

Cause

What was observed during troubleshooting.

Example:
"Inspection found kinked tubing between the filter pressure pod and filter, causing elevated filter pressure. Alarm cleared after tubing was rerouted and pressure readings stabilized."

Resolution

What action was taken.

Example:
"Corrected tubing route, verified no clamps or kinks remained, confirmed filter pressure returned to acceptable range, and monitored for recurring alarms. Device remained in service after clinical staff confirmed therapy could continue."

Helpful Details to Include (If Known)

• Alarm behavior
• Accessories swapped
• Power behavior
• Environmental factors
• Indicator lights
• Final device status

Final Thought

The Filter Extremely Positive alarm should be treated as a real pressure condition until proven otherwise. Start with patient safety, then check for clamps, kinks, circuit restriction, catheter issues, high return pressure, and filter clotting before suspecting the machine. If the alarm persists after circuit and clinical causes are addressed, escalation to pressure-sensor or ARPS evaluation is appropriate. Clear CCR documentation protects both patient care and the repair process.

That is successful troubleshooting.