Automated CBC Parameters

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Automated CBC Parameters and Quality Control
Joanna Ellis, MLS(ASCP)
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The Automated Complete Blood Count

• Most common test in the Hematology lab.
• Main Components of the CBC
• Cell counts
• Hgb
• RBC indices
• WBC differential absolute values and percent
• Indications for CBC
• Fatigue
• Weakness
• Infection
• Inflammation
• Bruising
• Bleeding

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CBC Parameters
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M77221
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CBCAdult Reference Ranges
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Linearity(Reportable Range)

• Instruments are calibrated for each analyte with
  a range that is clinically relevant.
• With concentrations above or below the reportable
  range or Linearity range, the result does not
  correspond with the calibration curve in linear
  fashion.
• Results outside of linearity are NOT acceptable.
• Linearity ranges vary by instrument.
• Example

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Advia Linearity Instrument Codes
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CBC Quality Control

• Commercial Controls
• 3 levels (low, normal, high)
• Values stored in instrument computer
• Levey-Jennings graph generated and stored for
  each parameter
• Mode to Mode QC
• Most automated hematology instruments have a
  primary and secondary mode of sample aspiration.
  Controls must be run on BOTH and correlate.
• PrimaryAutomated or Closed
• SecondaryManual or Open
• Delta Checks
• When the Laboratory Information System (LIS) and
  the instrument are interfaced (connected) delta
  checks are conducted by the LIS on select
  parameters.
• Current values compared to most previous result
• Differences greater than the limits set within
  the LIS are flagged

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WBC Parameter Interfering substances and
Implications
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RBC Parameter Interfering substances and
Implications
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HGB Parameter Interfering substances and
Implications
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HCT Parameter Interfering substances and
Implications
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MCV Parameter Interfering substances and
Implications
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RDW Parameter Interfering substances and
Implications
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Plt Parameter Interfering substances and
Implications
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WBC Differential ParametersClinical Implications
in Adults
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References

• Harmening., Denise, Clinical Hematology and
  Fundamentals of Hemostasis, 3rd edition, pp.
  593-599.
• Turgeon, Mary Louise, Clinical Hematology -
  Theories and Procedures, 3rd edition, pp373,
  376-382.
• Rodak, Bernadette, Diagnostic Hematology, 1st
  edition, p.605-606.
• Coulter STKS Operating Manual
• McKenzie, Shirlyn, Clinical Laboratory
  Hematology, 2nd edition,pp 813-829.
• "Complete Blood Count The Test." Lab Tests
  Online Welcome! American Association for
  Clinical Chemistry, 18 June 2010. Web. 13 Sept.
  2010. lthttp//www.labtestsonline.org/understandin
  g/analytes/cbc /test.htmlhowgt.
• "WBC Differential Count The Test." Lab Tests
  Online Welcome! American Association for
  Clinical Chemistry, 18 June 2010. Web. 13 Sept.
  2010.http//www.labtestsonline.org/understanding/
  analytes/dif ferential/test.htmlwhatgt.