Hematology Exam 1 Flashcards
Leukopenia
decreased WBC count
Leukocytosis
Increased WBC count
Leukemia
Uncontrolled proliferation of a clone of malignant WBCs
Neutrophilia
Increased neutrophils, often signals bacterial infection
Neutropenia
decreased neutrophils, many causes including viral infections or certain medications
thrombocytes
platelets
leukocytes
WBC
erythrocytes
RBC
Most common hematology test ordered
CBC
Plasma
The liquid portion of blood that provides coagulation enzymes
RBC count diluent used and dilution factor
Normal saline used at a 1:200 dilution
Anemia
loss of oxygen carrying capacity of RBC, often due to decreased RBC or decreased Hb
Polycythemia
increased RBC count, leads to hyperviscosity
Description of hemoglobin measurement (what reagent is used, what type of blood is used, how does the test work)
Drabkin’s reagent used (potassium cyanide and potassium ferricyanide) with whole blood.
Hemoglobin is converted to cyanmethemoglobin and absorbance is measured at 540nm on spec, color intensity compared to a standard and converted to a hemoglobin concentration
Hematocrit
%RBC in whole blood
How to perform a manual hematocrit
Put blood in capillary tube, centrifuge, measure column of RBCs and divide by total length (RBCs + plasma)
Hematocrit = RBC/Whole Blood
Function of erythrocytes
Biconcave cells filled with hemoglobin which transports O2 and CO2
Mean Cell Volume (MCV)
reflects RBC size (fL)
Mean cell hemoglobin (MCH)
mass of hemoglobin per cell (pg)
Mean cell hemoglobin concentration (MCHC)
reflects RBC staining intensity and amount of central pallor (g/dL)
RBC distribution width (RDW)
degree of variation in RBC volume (%)
high variation = increased RDW
low variation = decreased RDW
Reticulocytes (AKA polychromatic erythrocytes)
large, immature RBC released from bone marrow that stain slightly blue-gray
What does increased reticulocytes tell you?
Indicates the bone marrow responding to anemia or decreased oxygen carrying capacity (bone marrow is trying to increase RBC count)
Manual reticulocyte procedure
Counting reticulocytes by microscopy - reticulocytes will have a presence of RNA in the cell and will stain blue/gray on a Wright’s blood smear