The Complete Blood Count

1
The Complete Blood Count

• Clinical Pathology
• K. Canga, RVT

2
Reading and Assignments

• Read pp 32 38 (Start at CBC, end before
  histograms)
• You MUST register at IDEXXLearningCenter.com and
  complete the course titled The VetTest
  Certificate Course RACE 106-11660
• This is FREE, and will count as 3 hours of CE to
  use after you become licensed.
• The course will take 3 hours and you need to
  turn in a certificate of completion prior to
  using the IDEXX machines at school.
• Certificates are due by Monday, May 5. PLEASE
  print a hard copy. No Engrade or e-mail message
  will be accepted. (Yes, this is for points)

3
Composition of the CBC

• Total RBC count
• PCV
• Plasma Protein Concentration
• Total WBC count
• Blood film evaluation (differential WBC count,
  RBC and WBC morphological evaluation, platelet
  estimation)
• Reticulocyte count
• Hb Concentration
• Erythrocyte indices (Theyre baaack) ?

4
RBC Count

• Should be in the millions
• Usually done by machine
• Can be done manually with
• Unopette and Hemacytometer
• Is outdated and difficult to obtain diluents

5
PCV

• Packed Cell Volume
• Indicates the percent of packed red cells in a
  patients blood.
• Done with hematocrit tube that has been
  centrifuged
• Takes VERY little time and can be quick
  diagnostic tool
• Normal ranges?

6
Plasma Protein Concentration

• Utilize the already centrifuged PCV tube
• Read using a refractometer
• Helps to determine abnormal amounts of protein in
  blood
• Protein present may be from fat, or other
  sources.
• Normal Ranges?

7
Total WBC count

• Usually done by machine
• Can be done manually with unopette and
  hemacytometer method. (Again, outdated and
  difficult to obtain diluents)
• Critical in determining absolute number of WBCs.
  This is the number with diagnostic value.

8
Blood Film Analysis

• Used to calculate the relative WBC percentages
• Used to evaluate RBC and WBC morphologies
• Used to perform reticulocyte count if patient is
  anemic
• Used to Perform platelet estimation.
• REVIEW retic. and platelet calculations. I am
  not going to re-teach these.

9
Calculating the Absolute WBC count

• You must have done a relative percentage from a
  blood film. (Written as a )
• You must have a total WBC count
• You will then take each relative percentage and
  multiply each by the total WBC count from your
  CBC analyzed blood.

10
Calculating the Absolute WBC values

• Your relative percentages were as follows
• Neutrophils 52
• Lymphocytes 38
• Monocytes 7
• Eosinophils 3
• Basophils 0
• Take each cells percentage and multiply by the
  total WBC numbers from the machine readout. Lets
  say that your total was 38,000.

11
Your WBC total was 38,000

• 38,000 x 52 19,760 total neutrophils
• 38,000 x 38 14,440 total lymphocytes
• 38,000 x 7 2,660 total monocytes
• 38,000 x 3 1,140 total eosinophils
• 38,000 x 0 0 total basophils
• The is VERY important in your calculation.
  Simply hit the key after you punch in the
  number you are multiplying the total by.
• NOTICE that your numbers add up to 38,000!

12
Hemoglobin concentration

• Usually done by machine
• Different machines use different techniques to
  estimate Hb concentration
• Lysing solutions
• Photometrics
• Are only as accurate as machine is. Calibration
  is important.

13
Erythrocyte Indices

• MCV Average volume within RBC
• MCHC Average Hb concentration within RBC
• MCH Average weight of Hb within RBC
• Review these calculations please!

14
Performing the CBC and Clinical Chemistry Tests
on the IDEXX Machines

• Blood MUST be drawn in both Lithium-Heparin micro
  tube AND large purple top tube. (These are tubes
  designed for the IDEXX machines)
• You can use a serum separator tube in place of
  the lithium heparin tube.
• REMEMBER
• DO NOT remove the stopper from the large purple
  top tube.
• DO NOT fill tube past bottom of label (0.5 1.5
  cc)
• You WILL need to remove the top from the
  micro-tube.

15
IDEXX CBC and Chemistry

• Centrifuge the microtube or serum separator tube
  for 7 minutes.
• Transfer plasma or serum off and place in serum
  cup. (Barbie shot glass)
• Place purple top tube and grey top tube obtained
  from Ms. Kenner in CBC machine.
• Bar codes on purple and grey tubes MUST MATCH in
  order for your tests to be valid. (If purple
  tubes do not have a bar code, this is OK, as long
  as theyre the large tubes!)

16
IDEXX Machines

• To run the chemistry portion of the test, you
  will obtain test slides from Ms. Kenner
• On the Monitor of the VetLab Station, use the
  stylet to enter the following information
• Click Analyze Sample
• Enter Client VTI
• Enter P. Name Patient id is fine
• Select next and then select reason Routine
  SX/Wellness
• At the bottom of the screen, you will need to tap
  the test icons desired. (CBC and Chemistry) and
  THEN
• STOP

17
Running your Tests

• If you havent already loaded the large purple
  top and grey top tubes in to the CBC machine, do
  so now. Then hit RUN
• Look at the LED screen on the body of the Vet
  Test Machine.
• Follow prompts on the LED screen.
• This is where you will add the slides ONE AT A
  TIME. (DO NOT OPEN the foil until you are ready
  to load the slide in to the machine.)
• DO NOT touch the center of the slides. You will
  need to handle the slides by the edges and make
  sure the bar code is UP

18
Running your Tests

• Once you have placed all the slides in the
  machine, follow the prompts on the LED screen.
• Place pipette tip securely on the pipettor of
  machine.
• Press E on LED keyboard to continue the
  analysis.
• lower pipette into plasma and press button.
  Machine will beep 1 time. (Release button)
• 2 beeps Remove pipette
• 3 beeps wipe pipette tip and replace in machine
  within 20 seconds. You will hear one more beep
  after pipette is replaced.

19
Test is Running

• The machine will automatically pipette the
  appropriate amount of plasma on each slide to run
  the tests.
• Total run time is 6 minutes
• When test is complete, press E
• Remove pipette tip, empty used slide drawer
• Machine should start printing results. If not,
  press E and wait. If results are still not
  printing, try selecting option 2 print results.

20
Printers

• The internal printer on the IDEXX machine is
  disabled on our machine.
• We have an external printer connected to print
  results.
• PAPER MUST BE LOADED before you start running
  tests.