Unit 9 - Exam Blood Smear & RBC Morphology Flashcards
What is the data collected in a PBS
Staining quality
Distribution of cells
WBC estimation
PLT estimation
RBC morphology
WBC morphology
WBC differential
nRBC per 100 WBC diff
Where are PBS evaluated
Monolayer
What do the cells look like at the edges of the smear
Too widely spaced
RBCs lose central pallor
What do cells look like in an area that’s too thick
Cells too close together
Can’t see detail
Distortion
Pan-
All
a-
Without
Hypo-
Under
Hyper-
Over
poly-
many
-cytosis
excess
-philia
increased
-penia
low
-cythemia
blood cells
Pancytopenia
Low amounts of all cell lines
Thrombocytosis
Excess platelets
Polycythemia
Elevation of many cell lines
How are WBC estimates done
High and dry (400x, 40x objective 10x eyepiece)
Total number of WBC in 5 fields
Calculation should match 25% of the automated WBC
WBC estimate formula
Total WBC in 5 fields/5 * 2,000/uL = 4.0x10^3 WBC/mcL
How are PLT estimates done
Oil immersion (1000x, 100x objective 10x eyepiece)
Count total number of PLT in 5 fields
Calculate
PLT estimate formula
Total PLT in 5 fields/5 * 15,000/uL = 150x10^3PLT/uL
How are RBCs evaluated
Always at 1000x
Only in monolayer
Anisocytosis
Excess size variability
What can anisocytosis indicate
More than one cell population like high retic + normal cells or transfused cells + microcytes
How should anisocytosis correlate with RDW
Std. Dev. of MCV
>14.5%
How to visually evaluate anisocytosis
Comparing the largest and smallest cell in a field
What does microcytosis indicate
Hgb production porblem
Microcytosis is often accompanied by
hypochromasia
Microcytosis is present in
Iron deficiency anemia
Hemoglobinopathies
Thalassemias
Sideroblastic anemias
Lead poisoning
Anemia of inflammation (chronic disease)
Macrocytosis indicates a problem with
DNA synthesis
Macrocytosis causes cells to undergo
Megaloblastic changes (asynchronism)
Hgb synthesis okay , DNA not
Nucleus and Cytoplasm out of sync
Macrocytosis present in
Normal newborns
Megaloblastic Nutritional Anemias (B12, Folate, Pernicious anemia)
Megaloblastoid toxicity - DNA inhibitory drugs, chemo
High retic count (hemolytic anemia, acute blood loss)
Liver disease
Central pallor should be
1/3 of the cell
What is wrong in hypochrmasia
RBCs lack normal hemoglobin
Hypochromatic cells are usually also
Microcytic
Polychromasia indicates..
RBC immaturity
Active BM
Macrocytic cell with no central pallor is usually
a reticulocyte (polychromatic cell)
Definitive reticulocyte identification done with
Supravital stain
Increased Retics means
Body trying to compensate for blood loss or hemolysis
Decreased retics means
Something wrong with bone marrow production
Variation of RBC shape
Poikilocytosis
Poikilocytosis
Excess shape variability
Spherocytes appear
Small, dark, round, no central pallor
Spherocytes caused by
Defect in or loss of cell membrane
Spherocytes are usually also
Microcytic
MCHC in spherocytes
May be greater than 36 g/dL
Conditions causing spherocytes
Newborns
Normal RBC aging
Hereditary spherocytosis
Hemolysis
Burns
Post transfusion
Acanthocytes also called
Spurr cells