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Delta-Checked & Unlikely Test Results in CLICS, Managing

I. PRINCIPLE:

When the Delta Check symbol, or , appears next to a test result field on the CLICS Interfaced Instrument Results Review Release screen (IIRRR) or on the Transcription Review Release screen (TRR), it means that user-definable Delta Check parameters have been set for that test.

Electronic delta checking is a computer function that automatically monitors changes in consecutive measurements on an individual for a given analyte. Application of this set of analytical filters can

● reduce delays in the release of results that would otherwise trigger time and resource consuming investigation and, secondarily,

● help intercept erroneous results including results that fall within their reference range (Normal) that are never-the-less incorrect.

In addition to Reference (normal) Range, Critical values and Delta flagging, CLICS screens results of select analytes for Unlikely values. An “Unlikely” result is statistically improbable under any circumstances and needs to be investigated.

Delta Checks

Unlikely Results

II. PROTOCOL:

  1. Checks:
  2. If the is filled with a GREY color, delta check criteria were applied and the current result falls within preset limits. Additional investigation is not triggered by this event.
  3. If the is filled with a BLUE color, a significant change has occurred in the analytical result from the last time it was measured within the system and investigation is triggered prior to release of the result.
    1. If the flag occurs in the TRR screen, verify that there hasn’t been a simple data-entry error, then check the primary record against the transcribed result.
    2. If the first step doesn’t apply or the delta-flagged result isn’t explained, right-click the result field of the analyte in question to view the previous result along with its accession number and the date and time it was resulted. The Delta Parameters, Limit, Type and Dwell Time, which have been set for this constituent, will also be displayed.
    3. Next, carefully, inspect the sample/aliquot for visible signs of interfering substance that might affect testing either mechanically or optically:
      improper fill
      hemolysis
      icterus
      clotting
      sediment
      turbidity
    4. Re-verify the sample/aliquot ID. There’ll be a higher incidence of trouble here on non-direct tube analyses and transcribed results processes.
    5. If other patient results on the analyte in question were generated at about the same time, quickly spot-check them to make sure there’s not some kind of system error developing.
    6. If the change in the test value “makes sense” clinically, i.e., is the typical effect of medical intervention AND the above checks are OK, it can be released. This kind of delta-flagged result tends to reflect a significant movement towards nominal (from “abnormal” to “normal”) as in a rapidly rising Hgb in the face of transfusion or an improving Potassium for example in a patient that’s being rehydrated. Nursing staff on the patient’s unit may have to be consulted to help ascertain whether the result in question is clinically aligned.
    7. If there’s been no transcription error, if the physical integrity of the sample has been checked, if the sample/aliquot hasn’t been misidentified or loaded incorrectly on the instrument, if the analytical system is functioning properly, the result can be released.
      The will convert to a GREEN fill to acknowledge recognition of the delta flag and indicate that the operator has evaluated the result against the criteria listed above prior to release.

UCL Delta Check Parameters

      Analyte

      Delta Limit

      Delta Type

      Delta Dwell Time

      BUN

      50

      %

      3 days

      Glucose

      40

      %

      1 day

      Sodium

      9

      %

      2 days

      Potassium

      20

      %

      2 days

      Chloride

      9

      %

      2 days

      Calcium

      11

      %

      2 days

      Creatinine

      50

      %

      3 days

      Protime

      40

      %

      5 days

      APTT

      40

      %

      5 days

      ABO Group

       

      Absolute text string

      Open-ended

      Rh Type

       

      Absolute text string

      Open-ended

      Antibody Screen

       

      Absolute text string

      Open-ended

      HGB

      13

      %

      5 days

      WBC

      40

      %

      3 days

      Platelet

      30

      %

      5 days

      MCV

      3 fl

      Absolute

      12 days

      PSA

      60

      %

      24 months

      Bilirubin Tl

      30

      %

      10 days

       

Unlikely Test Results:
In addition to Reference (normal) Range, Critical values and Delta flagging, CLICS screens results of select analytes for Unlikely values. An “Unlikely” result is statistically improbable under any circumstances and needs to be investigated.

  1. If the result is a manual entry, review the raw data. Often transcription of the wrong number, decimal or entry into the wrong field is causative.
  2. Make sure the sample type matches the requisition and, if applicable, is properly selected on the instrument.
  3. Carefully inspect the sample itself for clots, extreme cloudiness, very high hematocrit, etc. If any of these are present, request a repeat sample acquisition.
  4. Check with the person who obtained the specimen and try to verify that it was collected properly. IV contamination and improper aliquoting continue to contribute to this kind of error. If there is any doubt here, request a repeat sample acquisition.
  5. Verify system integrity by reviewing surrounding results of the same constituent. If surrounding results are suspect, discontinue testing for that analyte and immediately contact an instrument specialist.
  6. Repeat the trial with a control close to the same concentration and then review the results with the supervisor/site pathologist.

       

    1. August 2002 S. Raymond
    2. August 2006 M. English (Revised: Added list of Delta parameters)
    3. July 2011 S. Raymond (Revised: added unlikely results protocol)

       

    Reviewer:

    Technical Director:

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