Hematology Rotation Quiz 1

Question 1

1. Into what three layers does anticoagulated blood settle when centrifuged or allowed to settle over time?

Answer 1

Upper layer – plasma
Middle layer – buffy coat which contains the white blood cells and platelets
Bottom layer – red blood cells

Question 2

Venipuncture above an IV line:

Answer 2

Dilution and contamination of the specimen. Decreased RBC, Hgb, WBC, Plt.

Question 3

What is the anticoagulant of choice for CBC? Storage and Temp limits?

Answer 3

K2 EDTA. Stored at 4 to 8 degrees C, EDTA blood samples with normal results may be analyzed up to 48 hours without significant loss of differential stability. Sample stability at room temperature is 24 hours. Samples stored at room temperature may exhibit an increase in MCV after 24 hours, which may be minimized by refrigeration. Allow refrigerated samples to come to room temperature and mix well before analysis.

Question 4

Other anticoagulants?

Answer 4

Na Heparin (green top) samples can be used for the HGB & HCT in an emergency only. Blood gas specimens can be used for the HGB & HCT in an emergency only. Citrated (blue top) blood can be used for platelet counts provided a correction is made for the dilution factor. The factor is 1.11 and a slide must be made from the citrated tube and correlated with the platelet estimate. For example, if the platelet count is 150,000, it is multiplied by the dilution factor (150,000 X 1.11 = 166500). The reported platelet count off the blue top tube would be 166,500. Blood from a pink top tube (EDTA tube used for blood bank) is acceptable but cannot be directly ran on the instrument. An aliquot label must be created. A sample from this tube must be obtained for testing before blood bank spins it down and removes the plasma. Cord blood is unacceptable.

Question 5

What is a Romanowsky Stain?

Answer 5

A stain made from water-soluble eosin, methylene blue, and absolute methanol. It used in Parasitology, Hematology, and Histology/Cytology. An example would be Wright-Giemsa stain.

Question 6

Hematocrit

Answer 6

Hematocrit is the ratio of the volume of red blood cells to the total volume of blood. It is expressed as a percentage.

Question 7

standard formula for calculating the number of cells counted in a hemocytometer.

Answer 7

Number of cells per ul or mm3 =
Number of cells counted x dilution x depth / Number of squares counted

Question 8

Identify the standard diluent for manual RBC counts in our lab, and why it is the diluent of choice.

Answer 8

The standard diluent for manual RBC counting is 0.9% normal saline. This solution is isotonic to RBC. At SFMC, we use Cellpack DCL, manufactured by Sysmex.

Question 9

SLIGHTLY BLOODY OR SLIGHTLY CLOUDY SAMPLE:

Answer 9

1:20 dilution: 100 ul of specimen and 1.90 ml of Cellpack DCL

Question 10

MODERATELY BLOODY OR CLOUDY SAMPLE:

Answer 10

1:100 dilution using 20 ul of specimen and 1.98 ml of Cellpack DCL

Question 11

GROSSLY BLOODY OR TURBID SAMPLE:

Answer 11

1:200 using 10 ul of specimen and 1.99 ml of Cellpack DCL OR
1:200 using 20 ul of specimen and 3.98 ml of Cellpack DCL

Question 12

Why are both sides of the Hemocytometer utilized?

Answer 12

Counting both sides of the hemocytometer is a QA check for proper pipette and plating technique. The cell count on one side of the hemocytometer should match the cell count from the other side within 20%.

Question 13

normal ranges for WBCs in males; females; newborns

Answer 13

female, male and child: 4,000-12000
newborn: 5000-21000

Question 14

iSED Quantitative Capillary Photometry:

Answer 14

The iSED uses quantitative capillary photometry (aggregation) to measure the
sedimentation rate faster than traditional methodologies by capturing the kinetics of RBC
aggregation in a controlled testing environment during the most critical phase of
sedimentation. This critical phase is referred to as the lag or Rouleaux formation phase.

Question 15

List the ESR method currently used at Saint Francis and the normal ranges.

Answer 15

The iSED is the method currently in use at OSF. The normal ranges are as follows:

Male <50 yrs: 0-15 mm/hr
Male >50 yrs: 0-20 mm/hr
Female <50 yrs: 0 – 20 mm/hr
Female >50 yrs: 0-30 mm/hr
Infant to Puberty: 3 – 13 mm/hr
Newborn: 0-2 mm/hr

Question 16

What is the significance of the ESR?

Answer 16

The ESR is a simple non-specific screening test that indirectly measures the presence of inflammation in the body. It reflects the tendency of red blood cells to settle more rapidly in the face of some disease states such as acute and chronic infections, tumors and degenerative diseases, usually because of increases in plasma fibrinogen, immunoglobulins, and other acute-phase reaction proteins. The greatest usefulness of this test lies in its ability to differentiate among diseases with similar symptoms or to monitor the course of a disease. Changes in red cell shape or numbers may also affect the ESR.

Question 17

State whether the ESR would be normal or increased in the following conditions and why?

Answer 17

pregnancy: normal to increased
severe anemia: markedly increased
polycythemia: normal
poikilocytosis: normal to decreased
multiple myeloma: increased

Question 18

What is the correct method of correlating the automated WBC count with a WBC estimate from the peripheral blood smear? What is the acceptable limit?

Answer 18

To perform a WBC estimate, scan 5 fields on 50 X and add up the total number of WBC’s seen. Divide this number by 3. The WBC estimate should be +/- 20% of the automated count. For example: 24 WBC’s are counted in 5 fields on 50 X. The WBC estimate is 24 divided by 3. The WBC estimate is 8

Question 19

What is the correct method of correlating the automated platelet count with a peripheral smear estimate? What is the acceptable limit?

Answer 19

Scan 5 fields on 100X and add up the total number of platelets. Divide this number by 5 to find the average number of platelets per field. Multiply this number by 15000. The platelet estimate should be +/- 20% of the automated count. For example: 50 platelet are counted in 5 fields on 100 X. 50 divided by 5= 10. 15000 X 10 = 150000.

Question 20

Explain how an absolute cell count is calculated for any given cell line. Use the example: WBC count = 6.7 x 103/ul; 67% neutrophils; 1.3% basophils.

Answer 20

The absolute count of a cell is calculated by multiplying the WBC count by reported percent of the cell. For example 6700 X 0.67 = 4489. The absolute neutrophil count is 4489. For the basophil count: 6700 X 0.013 = 87.1. The absolute basophil count is 87.

Question 21

Absolute Lymphocytosis

Answer 21

An increase in the amount of lymphocytes in the blood that exceeds the upper limit of the normal reference range.

Question 22

Absolute Neutropenia

Answer 22

A decrease in the amount of neutrophils in the blood that is below the lower limit of the normal reference range.

Question 23

Absolute Monocytosis

Answer 23

An increase in the amount of monocytes in the blood that exceeds the upper limit of the normal reference range.

Question 24

What is indicated by Reticulocytosis?

Answer 24

Reticulocytosis is a condition where there is an increase in reticulocytes (immature red blood cells). It is commonly seen in anemia. Reticulocytes are seen on blood films when the bone marrow is highly active in an attempt to replace red blood cell loss such as in hemolytic anemia or hemorrhage.

Question 25

Explain the RPI, including its purpose, method of calculation and the clinical significance of the results vs. a routine reticulocyte answer.

Answer 25

Reticulocytes that are released from the bone marrow prematurely are called shift or stress reticulocytes. These reticulocytes are shifted from the bone marrow to the peripheral blood in order to compensate for anemia or blood loss. Instead of losing their reticulum in 1 day like normal reticulocytes, these cells take up to 2.5 days to lose their reticulum. When erythropoiesis is evaluated, a correction should be made for the presence of shift or stress reticulocytes. Without this correction, the % of reticulocytes reported in the peripheral blood may be falsely increased without an increase in bone marrow erythropoiesis. The RPI is sometimes referred to as a corrected Reticulocyte count. Patients with an appropriate marrow response (>2.0) typically are not evaluated further. Patients with an inappropriate marrow response (< 2.0) may be further evaluated for nutritional deficiencies or marrow abnormalities.

Question 26

List some disease states or conditions in which the retic% is:

Answer 26

Increased – Pregnancy, Hemolytic Anemia, Acute Blood Loss
Decreased – Aplastic Anemia, Cirrhosis, IDA, B12 or Folate Deficiency

Question 27

State the formulas used to calculate the MCV, MCH and MCHC.

Answer 27

MCV = (HCT/RBC) x 10 Result is in fl

MCH = (HGB/RBC) x 10 Result is in pg

MCHC = (HGB/HCT) x 100 Result is in g/dl

Question 28

Normocytic, normochromic.

Answer 28

MCV in fl (82-96) MCHC in g/dl (32 - 36) Bone marrow failure, hemolytic anemias, leukemias, renal disease, acute blood loss, sickle cell anemia.

Question 29

Macrocytic, normochromic

Answer 29

MCV in fl >105 MCHC in g/dl (32 - 36) Megaloblastic anemia (pernicious, folate deficiency), B12 deficiency, liver disease, myelodysplasia, alcoholism

Question 30

Microcytic, hypochromic

Answer 30

MCV in fl < 82 MCHC < 32 Iron deficiency, thalassemia, unstable hemoglobins, chronic disease or infection, sideroblastic anemia

Question 31

What patient population normally has increased MCV’s (> 100) and MCH?

Answer 31

The neonatal or newborn population will have an increased MCV and MCHC.

Question 32

What is the definitive diagnostic test for Hb S?

Answer 32

Hemoglobin electrophoresis. The Pacific Hemostasis Sickle Screen Kit test is a qualitiative screening procedure and does not differentiate between Sickle Cell Disease (S/S) and Sickle Cell Trait (A/S).

Question 33

Specimen stability of a CBC

Answer 33

in room temp -24hrs
at 2-8 (refrigerated) - 48hrs

Question 34

The Rule of 3

Answer 34

The rule of 3 is defined as the Hemoglobin multiplied by 3 matching the Hematocrit by
+/- 3 %. This rule is based off of the fact that for every 1 gram of Hemoglobin, the
Hematocrit should rise by roughly 3%.

Question 35

What are some uses of the Hematocrit in the Laboratory?

Answer 35

This parameter indicates the viscosity of the blood sample. Hematocrit is an important
component of the calculated RBC indices. It is also useful in resolving the Turbidity flag
on the XN analyzer via spinning a manual hematocrit and comparing this value with the
analyzer value and verifying that the indices were calculated correctly.

Question 36

What is the basic principle of the iSED?

Answer 36

The iSED uses quantitative capillary photometry (aggregation) to measure the
sedimentation rate faster than traditional methodologies by capturing the kinetics of RBC
aggregation in a controlled testing environment during the most critical phase of
sedimentation. This critical phase is referred to as the lag or Rouleaux formation phase.

Question 37

increased ESR?

Answer 37

Pregnancy, severe anemia, multiple myeloma

Question 38

decreased ESR?

Answer 38

Sickle Cell Disease, Hereditary Spherocytosis

Question 39

What are some conditions in which the reticulocyte % is increased?

Answer 39

Pregnancy, Hemolytic Anemias, Acute Hemorrhage

Question 40

What are some conditions in which the reticulocyte % is decreased?

Answer 40

Aplastic anemia, Iron Deficiency Anemia, Cirrhosis, B 12 /Folate Deficiency

Question 41

What are stress/shift reticulocytes?

Answer 41

These are reticulocytes that are released from the bone marrow prematurely and they take
longer to mature and lose their reticulum in circulation than a normal reticulocyte. These
reticulocytes will falsely increase the % Retic value in the blood which will make it
appear as if the marrow is responding appropriately when actually it is not.

Question 42

It is acceptable to perform a full CBC with differential on a tube containing the anticoagulant Sodium Citrate? T or F

Answer 42

False