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Hematology City Control: Preparation, Application and Management

I. Principle:

A daily Hematology control specimen is used to maintain matched calibration and monitor the performance of the Hematology instruments used at each site under the direction of Dubuque Pathology Associates. The HemoCue Hemoglobin instruments being used at Medical Associates Satellites will also be monitored for Hemoglobin performance.

II. Clinical Significance: N.A.

III. Specimen:

2 - 10 ml EDTA samples from a normal patient obtained fresh each morning.

IV. Materials:

  1. 10 ml EDTA Vacutainer tubes (CardinalHealth #B2991-54)
  2. 4 ml EDTA Vacutainer tubes (CardinalHealth #B2953-12)

V. Reagents:

  1. EDTA Sequestor Sol (CardinalHealth #B2948)
  2. D-Glucose Anhydrous AR (CardinalHealth #4912-500)
  3. Glucose/EDTA:
    Add 50 gm Glucose to 50 ml EDTA. Mix well, label and store in a plastic bottle. Outdates 1 year after preparation.

VI. Standardization: N.A.

VII. Procedure:

  1. The overnight tech at Finley will prepare the city control each day.
    Note: The sample for the city control should be drawn from a fairly normal patient between the hours of 0300 and 0500.
  2. Draw the city control in two 10 ml EDTA Vacutainer® tubes. Invert the EDTA tubes at least 5 times immediately following collection.
  3. Add one drop of Glucose/EDTA to each tube. Place the samples on the rocker for a minimum of 10 minutes, and a maximum of 30 minutes.
  4. For Monday through Friday, aliquot the sample into seven 4 ml EDTA Vacutainer tubes. Use the volume comparator as a guide when preparing the aliquots.
    Location Volume

    MMC-DBQ 3 ml
    Finley 3 ml
    MMC-DV 2 ml
    MA (East) 3 ml
    MA (Bellevue) 1 ml
    MA (Galena) 1 ml
    MA (West) 3 ml
  5. For Saturday and Sunday, aliquot the sample into four 4ml EDTA Vacutainer tubes. Use the volume comparator as a guide when preparing the aliquots.
    Location Volume

    MMC-DBQ 3 ml
    Finley 3 ml
    MMC-DV 2 ml
    MA (East) 3 ml
  6. Seal the Vacutainer tubes. Label, date and place in individual plastic whirl pak bags. Consolidate all of Medical Associates individual bags into a bag marked Medical Associates (East). The individual bags will be sent out from this location.
  7. Samples should be refrigerated until the courier arrives to take them to their specific sites.
  8. Each site will run the City Control as part of the Daily Quality Control.

VIII. Limitations: N.A.

IX. Results Derivation:

  1. City Control results must be entered by 1000 AM each day. An exception would be specimens from Medical Associates satellite clinics, which may not be run and called until the following day.
  2. The city control data is recorded by site and method. A group mean is calculated for the measured parameters (WBC, RBC, Hemoglobin, MCV, Platelet) using the data collected on the Beckman Coulter LH500 & LH750 units.
  3. All city control data is plotted by constituent against the group mean. Color-coded charts are used to differentiate sites and instruments.
  4. The data is plotted and reviewed daily to watch for drifts or shifts from the group mean. The plotted data undergoes a retrospective monthly review by the Technical Director for trends, method bias and appropriate response.
  5. Based on city control data, appropriate corrective action is taken when necessary. An SMR is written to record the corrective action taken.
  6. The Beckman LH750 and LH500 are calibrated using Beckman Coulter S-CAL Calibrator material every 6 months. The Hemocue instrument accuracy (calibration) is not adjustable. Any performance concerns with these instruments would be handled through an instrument swap-out agreement.
  7. Entering City Control Data:
    City Control results must be entered into the “City Control Data Acq Logs” by 1000 A.M. each day.
    1. Go to the desktop on the Hematology CLICS computer and double click on “City Control Data Acq Logs” icon.
    2. Double click on the worksheet that corresponds to the current month.
      Note: If the program is currently in use at another computer a pop up box will appear that states “File in Use, City Control Data Acq Log is locked for editing”. Select “Cancel” and try again in a few minutes.
    3. Select the “WBC” tab in the lower left hand corner of the worksheet.
    4. In the “WBC raw data” table single click on the box that corresponds to today’s date and your site.
    5. Enter the city control result for the WBC channel and press “enter”.
    6. Select the “RBC” tab in the lower left hand corner of the worksheet.
    7. In the “RBC” raw data” table single click on the box that corresponds to today’s date and the desired site.
    8. Enter the city control result for the RBC channel and press “enter”.
    9. Repeat steps C-E to enter the remaining measured parameter city control data.
    10. Close out of the “City Control Data Acq Logs” worksheet. A pop up window will appear that states “Do you want to save changes you made to City Control Data Acq Logs”, select “Yes”.
    11. Close out of the “City Control Data Acq Logs” program.
  8. Reviewing the City Control Data:
    City Control results must be reviewed by each specific site by 1100 A.M. each day.
    1. Go to the desktop on the Hematology CLICS computer and double click on “City Control Data Acq Logs” icon.
    2. Double click on the worksheet that corresponds to the current month.
      Note: If the program is currently in use at another computer a pop up box will appear that states “File in Use, City Control Data Acq Log is locked for editing”, select “Read Only” to access data for review.
    3. Select the “WBC” tab in the lower left hand corner of the worksheet.
    4. Inspect the “Allowable range” section of the worksheet for any red asterisk (*) that corresponds to your specific site and day in question. The asterisk indicates that a site-specific value has exceeded the allowable range based on the calculated group mean.
    5. Repeat steps C and D for all measured parameter data. The Instrument Specialist office must be called to notify of any asterisk data.
    6. The Instrument Specialist will review the city control data and decide on the proper follow-up action. A typical response by the Instrument Specialist may be to have the specific site simply repeat the city control and call in the results. In the case of a potential specimen specific issue the Instrument Specialist may instead choose to have the commercial controls run and called in.
    7. In any case, the original recorded data will remain unchanged. Any requested city control repeats are called to the Instrument Specialist.
    8. Close out of the “City Control Data Acq Logs” worksheet.
    9. Close out of the “City Control Data Acq Logs” program.
  9. Plotting the City Control Data:
    City Control results are reviewed on a daily basis and plotted on a monthly basis by the Instrument Specialist.
    1. Go to the desktop and double click on “City Control Data Acq Logs” icon.
    2. Double click on the worksheet that corresponds to the current month.
    3. Select the “WBC” tab in the lower left hand corner of the worksheet.
    4. Highlight the “WBC Diff from X” field and select “copy” (ctrl + C).
    5. Close the worksheet and a pop up window will appear asking to save the information on the clipboard so that you can paste it later, select “Yes”.
    6. Close the “City Control Data Acq Logs” program.
    7. On the desktop, double click on “City Control Template” icon.
    8. Select “Raw Data” tab at bottom of worksheet.
    9. Click in the upper left hand corner box of the WBC field and select “Paste” (ctrl + V). All of the “WBC diff from X” data should now be pasted in the WBC field.
    10. Select the month box in column A, row 4 and edit to current month and year (Nov-08).
    11. Select the WBC tab in the lower left corner of the worksheet. This should bring up the WBC plotted data for the month in question.
    12. Select “Save As” option and change the “Save In” field to read “Desk Top”.
    13. Double click on “Scott & Dick’s Hematology” folder to select final destination and select “Save”.
    14. Give the file a new name and select “Save”. Example: CCWBC Nov 2008
    15. Close out of the “City Control Template” program.
    16. Repeat steps A-O to plot each of the city control parameters.

X. Expected Result(s) and/or Critical Values: N.A.

XI. Quality Control: N.A.

XII. References:

    1. S. Raymond: Technical Director, Dubuque Pathology Associates.
    2. S. Pfaff (Revised: Glucose/EDTA).
    3. November 1992 L. McGovern (Revised: VIII.)
    4. January 1993 B. Lucas (Revised: IV. , VII.)
    5. July 1995 S. Wallace (Revised: I., VII.4., VII.6., VIII.2., and VIII.3.,7.,&8.)
    6. February 1996 S. Wallace (Revised: VII.4., VIII.2.)
    7. April 1999 B. Lucas, S. Wallace (Revised: VII.4.-7. volumes, VIII. Advia 120.)
    8. December 1999 D. Stence (Revised: III.,IV.1.,VII.2-4.)
    9. December 2005 L. McGovern (Revised: for new instrumentation)
    10. April 2008 L. McGovern/S. Hosch (Revised: IX.7. S-Cal)
    11. November 2008 S. Wallace (Revised: IX.2.)
    12. July 2009 S. Wallace (Revised: combined with CC Data Management)

 

Comprehensive Review:

Instrument Specialist:

Technical Director:

 

Interim Review:
February 2010 J. Murphy (no changes)
July 2011 K. Moore (Revised: IX.1.)

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