Practicum Flashcards
Normal values for WBC
5000-10000
Normal values for RBC
male: 4.7 - 6.1 million/cm3
female: 4.2 - 5.4
Normal values for Hgb
male 14-18 g/dL
female 12-16 g/dL
Normal values for Hct
males 42-52%
females 37-47%
Normal values for Platelets
150,000-400,000
Normal values for Retics
0.5% - 2% (avg 1%)
Normal values for ESR
male: 0 - 15 mm/hr
female: 0 - 20
What quick quality control calculation can be used to check the accuracy of the RBC parameters as they are obtained from an automated counter?
RBC x 3 = Hgb
Hgb x 3 = Hct
Factors which can increase ESR.
anemia pregnancy infections alcoholism, cirrhosis, hepatitis MM Tilted tube Specimen too warm
Factors which can decrease ESR
polycethemia
sickle cell anemia (abnormally shaped RBCs in general)
spherocytosis
delay in performing test
What is the chief use of the osmotic fragility test?
Diagnosis of spherocytosis
What test is best to use to differentiate between homozygous and heterozygous sickle cell disease?
Hemoglobin electrosphoresis
How are reticulocytes stained? Which dye is best?
New methylene blue or cresyl blue are used as reagents to separate RNA in cells. Wright’s (supravital stain) is used to make RNA visible.
Retics seen as Polychromatophilic (“blue-green”)
What is the use of the reticulocyte test to the physician?
Helps in diagnosis and monitoring of anemia.
In what conditions would one expect to see an increased reticulocyte count?
Hemorrhage, including hidden bleeding or hemolysis
Splenectomy
Various anemias, especially hemolytic anemia
In what conditions would one expect to see an decreased reticulocyte count?
Bone marrow suppression (toxins, chemotherapy, radiation, etc.)
Aplastic anemia
Ineffective erythropoiesis (IDA, PA)
What is the proper procedure for a hematocrit?
Blood is collected in heparinized (red) capillary tubes. Seal one end. Spin in microhematocrit centrifuge to obtain optimal packed cells. Use Macromethod of Wintrobe or Micromethod (which needs non-heparinzed blue top tube if a venous draw) for Hct determination.
What happens to the value if microhematocrits are spun too long? Not spun long enough?
Too long:Hemolysis (falsely decreased Hct) Not long enough: cells will not pack
From the indices, be able to describe red cell morphology or give the morphological classification of the anemia.
MCV: indicates RBC size: 100=macrocytic
MCHC: indicates degree of hypochromia:
With what condition are burr cells associated?
Renal failure
Kidney disease
In what condition is punctate basophilia (basophilic stippling) frequently seen?
Lead poisoning
With what condition are Heinz bodies most closely associated?
G6PD deficiency
How are basophilic stippling and reticulum differentiated in the lab?
Baso stippling: stained with Romanowski (Wrights) and New Methylene Blue
Reticulum: use New Methylene Blue only
What is the best specimen to use for blood smears for RBC morphology?
Whole blood from EDTA tube
How can you adjust the color of Wrights stained smear?
Adjust the pH
What is the most prominent feature in a blood smear from a patient with ABO HDN?
Spherocytes
How to calculate MCV
MCV = Hct divided by # of RBCs times 10
Normal values for MCV?
Male: 80 - 94 fL (femtoliters)
Female: 81 - 99
How to calculate MCH
MCH = Hgb divided by # of RBCs times 10
Normal values for MCH?
Male & Female: 27 - 31 pg (picograms)
How to calculate MCHC
MCHC = Hgb divided by Hct times 100
Normal values for MCHC?
32% - 36% (or g/dL)
From the indices, be able to suggest a diagnosis of anemia.
MCV increased, MCHC normal(Macrocytic/Normochromic) = liver disease, B12 deficiency, folate deficiency, PA, alcoholism
MCV, MCHC decreased (Microcytic/Hypochromic) = IDA, Sideroblastic, Thalassemia, Lead Poisoning
MCV, MCHC normal (Normocytic/Normochromic) = Aplastic anemia, and any other anemia not listed above
What is the appearance of the blood smear in iron deficiency anemia?
Microcytic, Hypochromic
also, serum iron decreased, TIBC increased
What is the appearance of the blood smear in folic acid deficiency?
Macrocytic, Hypochromic
PA, but no neurological symptoms
What are the causes of aplastic anemia? What are the blood findings?
Bone marrow suppression, failure or replacement, usually from chemical or radiation exposure.
Pancytopenia (WBC, RBC, Plt, Retic have low counts)
Normocytic/Normochromic
No signs of increased RBC formation, decreased bone marrow.
What is a common characteristic of all hemolytic anemias?
Increased RBC destruction
What is an unusal finding that is a means of differentiating AIHA from other hemolytic anemias?
Positive DAT (Direct Coombs Test)
What is pancytopenia?
Decreased RBC, WBC and platelets
What information is included in a WBC differential?
- Count & classification of leukocytes
- Platelet count
- RBC morphology
What is the most common WBC in a differential?
Segmented Neutrophils
What is the most common WBC in children under one year of age?
Lymphocytes
What is the least common WBC in a normal smear?
Basophils
What is the largest WBC in a normal smear?
Monocyte
Which immature RBCs are classified as NRBCs in a differential?
Blast cells
Prorubricytes
Rubricytes
Metarubricytes
What is the appearance of a plasma cell?
Eccentric nucleus with clumped chromatin, basophilic cytoplasm with a clear perinuclear halo (hof).
Is a plasma cell likely to be found in the peripheral blood?
No.
normally ~1% of nucleated cells in bone marrow
What is the meaning of the term “shift to the left”?
Increased immature granulocytes (blast, pro, myel, meta, band)
What is the meaning of the term “shift to the right”?
Increased mature cells (segs & hypersegs)
How is a diagnosis of Hereditary Elliptocytosis made?
At least 25% of RBCs are elliptical/oval shape in peripheral blood smear, osmotic fragility testing, an autohaemolysis test, and direct protein assaying by gel electrophoresis. [fun fact: it’s normal in camels]
What are the distinguishing characteristics of Hodgkin’s disease?
- Slow relentless progression
- Leukemoid rxn w/ eosinophils
- Reed-Sternberg cells
What are the normal features of a smear from a newborn that might be considered abnormal in an adult?
NRBCs
Polychromasia
young WBCs, etc.
How would you describe a Downey type atypical lymphocyte as is appears on a Wright’s stained smear?
Eccentric nucleus w/ dense chromatin, may have open spaces. Abundant smooth cytoplasm that’s pale near nucleus, various shades of blue toward periphery & scallops around surrounding RBCs with blue tint where it touches RBCs. May have azurphilic granules & vacuoles. Easily confused w/ monocytes.
At what stage of development does differentiation of the granules of a granulocyte take place?
Myelocyte
How is the metamyelocyte differentiated from the myelocyte?
Myelo: nucleus round to oval, may have one flat side
Meta: nucleus kidney bean shaped
Procedure for performing a total eosinophil count.
Must be done so as to count a larger volume, either by using a special counting chamber or by counting both sides of a Neubauer hemocytometer. Whole blood is diluted w/ staining sol’n. Use maximum light on microscope, count entire ruled area on both sides on low power. Calculation: Total # cells times 10 (dilution) divided by 1.8 mm3.
With what conditions are an increased eosinophil count associated?
allergic disease skin disorders parasitic infections blood diseases splenectomy
Normal values for CSF cell counts
adults: 0 - 5 mononuclear cells/uL, zero RBCs
neonates: 0-30 mononuclears, zero RBCs
What test is the best measure of the erythroid activity of the bone marrow?
Reticulocyte count
What conditions can not be absolutely diagnosed without a bone marrow aspirate?
Myeloproliferative disorders Aplastic anemia Lymphoma Tumors Leukemia Pernicious anemia (has megaloblasts in marrow)
What is the chief use of the LAP?
Differentiate leukemoid reaction (increased) from CML (decreased)
Why is it necessary to correct a WBC count if more than 5 NRBCs are present on a peripheral blood smear and how is the correction made (be able to do calculation)?
False increase of WBC count.
Calculate: # WBCs times 100 divided by 100 plus the # of NRBCs per 100 WBCs
Incidence of leukemia in various age groups.
ALL - most common in children
CML - middle age
CLL - older pt.s
What is the typical picture in the peripheral blood in acute leukemia?
Severe normocytic-normochromic anemia
Decreased RBCs
Thrombocytopenia
Increased immature cells
At the time of diagnosis, which leukemia frequently presents with a greatly increased platelet count?
CML (Chronic Myelocytic Leukemia)This is a case study
AML
(the typical blood picture)
Large # myeloblasts (60-90% of cells)
Scattered segs but no intermediate cells (differentiates AML from CML or leukamoid rxn)
Severe N/N anemia
Polychromasia
NRBCs
Thrombocytopenia w/ large or bizarre looking plt.s
ALL
(the typical blood picture)
> 60% lymphoblasts
Severe N/N anemia, usually no NRBCs
Thrombocytopenia
(this is a case study)
CML
the typical blood picture
Increased leukocytosis Increased all stages of granulocytes, Increased eos, Increased basos, Increased platelets at first, later decreases N/N anemia, incl. NRBCs Case study)
CLL
the typical blood picture
60-95% small, mature lymphs
Increased Smudge cells & Eos
All stages granulocytes
Hodgkin’s
the typical blood picture
Not terribly abnormal or specific Mild anemia Thrombocytopenia Leukocytosis usually granulocytes, esp. Eos (leukemoid rxn w/ eosinophilia) Decreased lymphs
Following splenectomy
the typical blood picture
Pappenheimer bodies HJB Cabot rings Target Cells Aniso & Poik (tear drop, bite cell, frags) Increased platelets
Megaloblastic anemia
the typical blood picture
Normochromic RBCs, Aniso & Poik
Macro Ovalocytes
Pancytopenia
Hyper segs w/ shift to right
Polycythemia vera
the typical blood picture
N/N RBCs but may become Micro/Hypo Increased RBCs Occasional NRBCs Immature grans (myelos & metas) Basophilic stippling Increase Eos & Basos Large, bizarre platelets with possible clumping
Myelofibrosis
the typical blood picture
Moderate N/N anemia
Polychromasia
NRBCs
Aniso & Poik (tear drop, ovalo, sphero)
WBC normal to increased w/ shift to left
Plts increased at first, later decrease with giant, bizarre forms
DIC
the typical blood picture
Thrombocytopenia Micro-platelets Leukocytosis Schistocytes Decreased Retics
AIHA
N/N anemia Macrocytic Polychromasia Spherocytes NRBCs Schistocytes, Ancanthocytes, Burr Cells Erythrophagocytosis by monocytes WBC increased with shift to left (case study)
Thalassemia major
Severe Microcytic/Hypochromic anemia
Aniso & Poik (target, burr, schisto, sphero, acantho)
Polychromasia
Many NRBCs
RBC inclusions (HJB, baso stippling, etc.)
Increased WBC with shift to left
(case study)
Thalassemia minor
Mild microcytic/hypochromic anemia Polychromasia Target cells Occassional NRBCs Baso stippling WBC usually normal
Multiple myeloma
N/N anemia Rouleaux WBC normal to decreased Occasional plasma cells & NRBCs Increase lymphs, Eos, & young granulocytes
Infectious Mononucleosis
Slight luekocytosis
Atypical Lymphs (Downey cells) instead of monos
Rare to few immature lymphs
Plt & RBCs normal
How do you do an indirect platelet count (platelet estimate) and how do you report out platelets in reference to your estimate?
(at CGH) Count platelets in 5 fields on high power at the feathered edge of smear, multiply by 4.
Report as adequate, increased, or decreased
How are PNH and PCH diagnosed in the lab and how do these conditions differ?
PCH: extrinsic, D-L antibody, extracorpuscular defect. Diagnose by Donath-Landsteiner Test.
PNH: intrinsic, acquired, sensitive to complement. Diagnosed by Hams’s Test or Sugar Water Test.
Which layer of the blood is used for making an L.E. prep?
Buffy coat
Which group of disorders is classified by using the FAB system of classification?
Acute Leukemias
What is the use of the Kleihauer-Betke technique or the Fetaldexx stain?
Measures the amount of fetal Hgb transferred from the fetal bloodstream to the mother’s bloodstream; used for D neg mothers.
Which age group has the highest values for the RBC parameters?
newborns
What is the Coulter principle for cell counting?
Interruption of a light source as it passes through a flow cell (flow cytometry)
How would you obtain a blood specimen from a patient who has IV solutions running into both arms?
Choose a vein distal from (below) the IV site (such as the hand) or ask nurse to turn off one IV 15 minutes before draw.
