CBC quantifies 3 types of blood cells
-RBCs
-WBCs
-Platelets
Define hematocrit
% of blood composed of RBcs
Define differential
Different types of WBCs present
Process of CBC
3-10 ml of whole blood drawn into tube containing anticoagulant (EDTA, Heparin, Cirtrate)
Most common anticoagulant used with CBC
EDTA, purple top
What are the 3 quantitative values in the RBC parameters?
-Hemoglobin
-Hematocrit
-RBC count
How is hemoglobin measured?
Spectrometry, measured by absorbance at 540nm
What are the qualitative/calculated RBC parameters?
MCV: average volume of each red blood cell (RBC volume/RBC count)
MCH: average hemoglobin in each RBC (Hgb/RBC)
MCHC: average Hgb concentration in each RBC (Hgb/Hct)
Define reticulocytes
Immature anucleated cells containing RNA
-Reflect bone marrow’s ability to make new RBCs
Define polycythemia
increased hgb, hct, or RBC count
Primary cause: bone marrow proliferative disease
Secondary: sleep apnea, smoking, living at high altitudes
Examples of error in RBC parameters
Total RBC count:
-Falsely increased: High WBC count
-Falsely decreased: Hemolysis, clotting
Hct:
-Falsely increased: Giant platelets
-Falsely decreased: Hemolysis, clotting
MCV:
-Falsely increased: Cell clumping
-Falsely decreased: Giant platelets
Examples of differential WBC
-Cells of each type: neutrophils, basophils, eosinophils, monocytes, lymphocytes, immaured WBCs
WBC are analyzed how?
Flow cytometry
-Light scatter (forward is cell size, side is complexity/granularity)
