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What This Guide Helps With
This guide assists Clinical Engineering in troubleshooting situations where an NxStage System One HD machine triggers blood leak detector alarms. These alarms indicate that the machine has detected blood in the dialysate or sensing system, which could be caused by external issues such as tubing misplacement, leaks, or sensor contamination, before assuming internal sensor failure.
Step-by-Step Troubleshooting
Ensure Patient Safety First
- Stop treatment immediately and move the patient to another machine if needed.
- Confirm the patient is stable and no blood loss is occurring.
Why: Blood leak alarms are critical for patient safety; never troubleshoot on an active patient.
Inspect Bloodlines and Connections
- Check all arterial, venous, and dialysate connections for tightness and proper installation.
- Look for loose fittings, cracks, or clamped lines that may allow leaks.
Why: Improperly seated or damaged lines are the most common external cause of blood leak alarms.
Examine the Dialyzer
- Inspect the dialyzer for cracks, broken ports, or leaks.
- Ensure that the blood compartment and dialysate compartment are correctly connected.
Why: A compromised dialyzer can allow blood to enter the dialysate path.
Check for Contamination on the Sensor
- Inspect the blood leak detector sensor (optical sensor) for dried blood, condensation, or debris.
- Clean the sensor according to NxStage recommended procedures (external wipe only).
Why: Dirt or residue on the sensor can trigger false alarms.
Verify Machine Setup and Alarms
- Ensure the alarm threshold is set correctly and the machine has completed its priming cycle.
- Reset the machine and re-prime if necessary.
Why: Improper priming or configuration can trigger a false blood leak alarm.
Swap Consumables if Needed
- If possible, replace the dialyzer or blood tubing set with a known good set to see if the alarm clears.
Why: Confirms whether the alarm is due to consumable integrity.
If the Problem Persists
All common external causes have been ruled out.
The blood leak sensor or internal detection circuitry may be faulty.
Action:
- Remove the machine from service.
- Label as Out of Service.
- Send to NxStage-authorized repair or Clinical Engineering bench evaluation.
Knowing when to escalate prevents patient harm and unnecessary troubleshooting on sensitive electronics.
Clinical Use Tip
- Never attempt to continue dialysis with a blood leak alarm active.
- Always move the patient to a safe alternative machine.
- Only perform troubleshooting once the patient is no longer connected.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
“Blood leak alarm keeps triggering during treatment.”
Cause
What was observed during troubleshooting.
Example:
“Inspection revealed blood leak detector sensor had dried blood residue; tubing connections were verified intact.”
Resolution
What action was taken.
Example:
“Cleaned sensor and replaced tubing set; machine successfully passed self-test. If alarm persists, machine removed from service for repair.”
Helpful Details to Include
- Sensor appearance (clean/dirty)
- Dialyzer integrity
- Bloodline inspection results
- Alarm pattern (continuous, intermittent, during priming)
- Any unusual sounds or condensation in sensor area
Final Thought
Patient safety is paramount. External checks often resolve blood leak alarms. Following a logical, stepwise approach prevents unnecessary service calls and ensures proper documentation. Escalate only when external causes have been ruled out.
That is successful troubleshooting.