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What This Guide Helps With
Troubleshoots repeated sample-quality or volume errors caused by specimen condition, tube selection, placement, aspiration access, or recurring analyzer sampling problems.
Step-by-Step Troubleshooting
1. Protect Patient Results and Identify the Affected Specimen
Do not repeatedly aspirate a patient specimen when the analyzer is reporting clot, bubble, or insufficient-volume conditions.
Determine:
- Which specimen is affected
- Whether the problem follows one tube
- Whether multiple specimens are affected
- The exact analyzer message
- Whether any result was generated before the error
Follow laboratory procedure for questionable or partially processed samples.
Expected outcome: The affected specimen is identified and unsafe repeat processing is avoided.
2. Inspect the Specimen Externally
Have laboratory personnel evaluate the specimen for:
- Visible clot
- Fibrin
- Foam
- Air bubbles
- Insufficient volume
- Abnormal separation
- Container damage
- Leakage
Clinical Engineering should not independently alter or reprocess patient specimens outside laboratory procedure.
Expected outcome: Obvious specimen-related causes are identified or ruled out.
3. Verify Tube Type and Placement
Confirm with laboratory staff that:
- The appropriate specimen container is being used
- The tube is correctly seated
- The tube is not tilted
- Labels are not interfering with seating
- The sample is accessible to the analyzer's aspiration path
Expected outcome: The sample container is positioned correctly and can be accessed normally.
4. Compare With Another Approved Sample
Determine whether a different verified specimen or laboratory-approved test sample runs normally in the same rack or loading path.
Expected outcome: Normal processing of another sample suggests the original specimen or container is the primary cause.
5. Inspect the Rack or Carrier
Check for:
- Cracks
- Deformation
- Contamination
- Poor tube retention
- Incorrect orientation
Replace a suspect rack with a known-good compatible rack if appropriate.
Expected outcome: The carrier maintains the sample in the correct aspiration position.
6. Check for Repeated Errors Across Multiple Samples
If multiple unrelated specimens show similar errors, verify:
- Probe/aspiration alarms
- Wash and fluid status
- Waste status
- Accessible probe cleanliness
- Analyzer readiness
A broader pattern makes a single specimen problem less likely.
Expected outcome: The issue is correctly classified as specimen-specific or analyzer-wide.
7. Inspect Accessible Sampling Areas
With the analyzer safely stopped according to normal procedures, inspect visible sampling areas for:
- Dried specimen material
- Debris
- Evidence of a spill
- Obvious probe damage
Use only approved cleaning procedures.
Expected outcome: Accessible sampling areas are clean and visibly intact.
8. Verify Corrected Operation
After the laboratory has corrected or replaced the specimen as appropriate:
- Confirm normal sample detection
- Confirm aspiration occurs without repeat errors
- Verify the analyzer completes expected processing
- Have laboratory staff determine whether repeat or confirmatory testing is required
Expected outcome: The replacement or corrected sample processes normally. Troubleshooting can stop when consistent aspiration is demonstrated.
9. Escalate Analyzer-Wide Repeated Errors
If properly prepared samples with sufficient volume repeatedly trigger the same type of error, stop external troubleshooting.
Do not adjust internal pressure, sensing, aspiration, or probe calibration systems without authorized procedures.
Expected outcome: A potential analyzer sampling or sensing problem is escalated.
If the Problem Persists
Common specimen, container, carrier, volume, and accessible contamination causes have been ruled out. The remaining problem may involve aspiration sensing, pipetting, pressure detection, fluidics, probe positioning, or service-level calibration.
The affected analyzer or module should be:
- Removed from service when reliable specimen aspiration cannot be assured
- Labeled Out of Service
- Sent for repair or qualified service evaluation
- Evaluated using Roche-approved documentation and approved test equipment
- Repaired or calibrated only by qualified personnel
Required functional checks and laboratory QC must be completed before return to patient testing.
Knowing when to stop external troubleshooting and escalate is proper troubleshooting.
Clinical Use Tip
When the error follows one specimen, preserve specimen integrity and involve laboratory staff before repeatedly rerunning or manipulating the sample.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Laboratory staff reported repeated low-volume errors on one specimen despite multiple loading attempts."
Cause
What was observed during troubleshooting.
Example:
"Clinical Engineering found the tube contained insufficient accessible sample volume for reliable aspiration."
Resolution
What action was taken.
Example:
"Laboratory staff provided an appropriate replacement specimen, Clinical Engineering verified normal sample handling, and the analyzer completed processing without repeat aspiration errors."
Helpful Details to Include (If Known)
- Exact clot, bubble, or volume message
- Specimen type
- Tube condition
- Visible clot, fibrin, foam, or bubbles
- Approximate available sample volume
- Tube seating and label placement
- Rack condition
- Whether other samples process normally
- Probe or fluidics alarms
- Cleaning performed
- Result after replacement specimen
- Final analyzer status
Final Thought
Repeated sample-quality errors should be separated from analyzer problems by checking the specimen, tube, carrier, and aspiration path in order. Preserve sample integrity, verify successful processing, and escalate broader repeated failures.
That is successful troubleshooting.