On this page
Asset Type
Manufacturer
Model
What This Guide Helps With
Use this guide for inaccurate, unstable, or implausible arterial or venous pressure readings related to tubing, transducers, connections, or setup.
Step-by-Step Troubleshooting
1. Protect the Patient
Do not rely on questionable arterial or venous pressure monitoring during dialysis. If the readings are unreliable during treatment, follow clinical procedures to maintain patient safety and transfer to another verified machine when necessary.
Expected outcome: The patient is not dependent on unreliable extracorporeal pressure monitoring.
2. Confirm Which Pressure Reading Is Affected
Determine whether the problem affects:
- Arterial pressure
- Venous pressure
- Both
- A fixed value
- A fluctuating value
- An implausible value before connection
- A reading that changes when tubing is moved
Record any associated alarm.
Expected outcome: The affected pressure channel and failure pattern are identified.
3. Inspect Pressure Lines and External Connections
Check the associated pressure-monitoring tubing and external connections for:
- Kinks
- Occlusion
- Loose fittings
- Disconnection
- Cracked tubing
- Moisture where it should not be present
- Incorrect routing
Do not allow fluid into areas intended to remain dry.
Expected outcome: The pressure line is intact, correctly routed, and securely connected.
4. Inspect the Transducer Protector or Equivalent Disposable Interface
Verify the disposable pressure interface is correctly installed and not wet, blocked, damaged, or contaminated.
If contamination or fluid intrusion is suspected at the machine-side connection, remove the device from clinical use until evaluated according to approved procedures.
Expected outcome: The disposable pressure interface is dry, unobstructed, and properly installed.
5. Verify Extracorporeal Circuit Setup
Have qualified dialysis staff verify the blood tubing set is correctly loaded and that clamps, chambers, and access connections are positioned as intended.
A circuit restriction or setup problem may produce a real abnormal pressure rather than an inaccurate measurement.
Expected outcome: The circuit contains no obvious external restriction or setup error explaining the pressure reading.
6. Compare With a Known-Good Disposable Setup
When appropriate, replace the suspect disposable pressure component or circuit with an approved known-good set during nonpatient testing.
Do not reuse a questionable disposable solely for troubleshooting convenience.
Expected outcome: Pressure behavior returns to normal if the disposable was the cause. If so, complete verification and stop troubleshooting.
7. Check Baseline Behavior Without Patient Connection
Using the approved preparation or test condition, observe whether arterial and venous pressure readings behave plausibly before patient use.
Do not perform unauthorized calibration adjustments.
Expected outcome: Pressure channels demonstrate stable and appropriate baseline behavior.
8. Verify With Approved Test Equipment
If required, test pressure measurement performance using manufacturer-approved procedures and calibrated test equipment.
Differentiate between a true circuit pressure problem and a machine measurement problem.
Expected outcome: Pressure measurement performance passes the approved verification. Troubleshooting can stop.
If the Problem Persists
If tubing, disposable interfaces, circuit setup, and approved pressure verification have been checked and the readings remain inaccurate or unstable, common external causes have been ruled out.
Possible remaining categories include internal pressure sensing, pneumatic pathways, calibration, signal processing, or control-system faults. Do not perform unauthorized sensor adjustment or internal pneumatic repair.
The device should be:
- Removed from service
- Labeled Out of Service
- Sent for repair or bench evaluation
- Evaluated using appropriate Nipro documentation and approved test equipment
- Repaired or configured only by qualified personnel
Pressure monitoring must pass required verification before the unit returns to service. Knowing when to stop external troubleshooting is proper troubleshooting.
Clinical Use Tip
Always determine whether an abnormal pressure is a real circuit condition before treating it as a measurement fault.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Dialysis staff reported the SURDIAL X venous pressure reading was unstable during setup."
Cause
What was observed during troubleshooting.
Example:
"Clinical Engineering found the disposable venous pressure line kinked near its connection."
Resolution
What action was taken.
Example:
"Clinical Engineering corrected the tubing routing, repeated the approved setup and pressure checks, verified stable readings, and returned the machine to service."
Helpful Details to Include (If Known)
- Arterial, venous, or both channels affected
- Exact alarm or displayed condition
- Pressure-line condition
- Transducer protector condition
- Circuit routing
- Known-good disposable substitution
- Whether fluid entered the monitoring connection
- Results of pressure verification
- Final machine status
Final Thought
Pressure readings are part of the dialysis safety system. Verify the extracorporeal circuit and disposable interfaces first, distinguish real pressure from measurement error, and require successful pressure verification before return to service.
That is successful troubleshooting.