Hematology Chapter 11 Review Questions

The mean cell volume (MCV) on a patient is calculated to be 115 fL and the mean cell hemoglobin concentration (MCHC) is 35 g/dL. What, in general terms, must be true of the mean cell hemoglobin (MCH) if it is consistent with the above two indices? a. It is impossible to know. b. It should be in the reference range. c. It should be below reference range. d. It should be above reference range.

d

What error was probably made if red cells are seen when attempting to manually count white blood cell (WBCs) on a hemocytometer? a. Unopette was not mixed before charging the hemocytometer b. Diluent was squeezed out and lost when filling the Unopette c. The wrong dilution was made. d. Unopette was not allowed to sit for 10 min. for complete RBC lysis

d

Which of the following could account for red cell indices in which there are no determinable red cell morphologies that would support the results? a. There is no way to come up with a likely cause. b. There is probably an error in the hemoglobin. c. There is probably an error in the red cell count. d. There is probably an error in the micro hematocrit.

b

Which of the following red cell indices support microcytic hypochromic red cell morphology? MCV (fL) / MCH (pg) / MCHC (g/dL) a. 120 / 36 / 35 b. 68 / 22 / 28 c. 90 / 30 / 34 d. 75 / 30 / 34

b

Which of the following would cause a manual cell count to be falsely high? a. Unopette not mixed before charging the hemocytometer b. not wiping excess blood from outside of pipette when filling c. using a smaller volume pipette than that specified by the Unopette system d. pulling blood out of the pipette when wiping away excess on the outside

b

A hemoglobin of 19 g/dL is normal for which of the following patients? a. newborn b. 2-year-old child c. adult female d. adult male

a

Any of the following could be an explanation for the invalid hemoglobin for Mary Jones except: a. Blood sample is hemolyzed. b. Lipemia is present in the plasma. c. Patient has hemoglobin S. d. Patient's white count is 150.0 x 109/L

a

In the four large corner squares of a hemocytometer, 95, 102, 105, and 98 white blood cells were counted from a 1:20 dilution. Select the correct interpretation for the white blood count calculated from these values. a. normal for infant and elevated for an adult b. normal for any patient c. elevated for any patient d. normal for an infant and decreased for an adult

a

Manual cell counting methods in automated hematology laboratories are used for all of the following except: a. routine testing b. very low counts c. malfunctioning automated instruments d. counting spinal fluids

a

On a standard reticulocyte preparation with new methylene blue, 100 cells are counted that contain blue-stained granulofilamentous material. The red blood count is 3.22 x 10^12/L, and the hematocrit is 30%. Calculate the reticulocyte count as a percentage. a. 0.32 x 10^12 / L b. 3.2 x 10^12 / L c. 32.2 x 10^12 / L d. 0.99 x 10^12 / L

a

Which of the following could cause the microhematocrit to be falsely decreased? a. specimen contaminated with intravenous (IV) fluid b. trapped plasma from abnormally shaped red cells c. dehydration d. insufficient centrifugation

a

Which of the following red cell indices support macrocytic normochromic red cell morphology? MCV (fL) / MCH (pg) / MCHC (g/dL) a. 120 / 36 / 35 b. 68 / 22 / 28 c. 90 / 30 / 34 d. 75 / 30 / 34

a

For which patient is a hemoglobin of 10.5 g/dL normal? a. newborn b. 2-year-old child c. adult female d. adult male

b

On a standard reticulocyte preparation with new methylene blue, 100 cells are counted that contain blue-stained granulofilamentous material. The red blood count is 3.22 x 10^12/L, and the hematocrit is 30%. Calculate the mean cell volume (MCV). a. 80 fL b. 93 fL c. 98 fL d. 108 fL

b

Ten nucleated RBCs are found on a blood smear when differentiating 100 WBCs. What is the corrected WBC count if the automated cell counter printed a WBC count of 10.0 x 10^9/L? a. 0.91 x 10^9/L b. 9.1 x 10^9/L c. 91.0 x 10^9/L d. 10 Nucleated Red Blood Cells (NRBCs) are not enough to require a correction

b

What is the total volume for one side of a hemocytometer if the ruled area is 3 x 3 mm and the depth is 0.1 mm? a. 0.3 mm^3 b. 0.9 mm^3 c. 1.0 mm^3 d. 9 mm^3

b

On a standard reticulocyte preparation with new methylene blue, 100 cells are counted that contain blue-stained granulofilamentous material. The red blood count is 3.22 x 10^12/L, and the hematocrit is 30%. Calculate the corrected reticulocyte count. a. 1.5% b. 3.0% c. 6.7% d. 15.0%

c

On a standard reticulocyte preparation with new methylene blue, 100 cells are counted that contain blue-stained granulofilamentous material. The red blood count is 3.22 x 10^12/L, and the hematocrit is 30%. Calculate the reticulocyte production index (RPI). a. 1.5 b. 2.7 c. 3.4 d. 13.4

c

On a standard reticulocyte preparation with new methylene blue, there are 100 cells counted with blue-stained granulofilamentous material. The red blood count is 3.22 x 10^12/L and the hematocrit is 30%. Calculate the reticulocyte count as a percent. a. .1% b. 1% c. 10% d. 100%

c

The platelet count from the automated cell counter is 80 x 10^9/L. Platelet satellites around neutrophils are observed on the blood smear estimate. A sodium citrate tube is drawn and the count reads 300 x 10^9/L from the cell counter. What platelet count x 10^9/L should be reported? a. 80 b. 300 c. 330 d. the estimated count from the blood smear

c

Twenty cells are counted in one of the nine large squares of a hemocytometer. The sample is diluted 1:10. How many are present per L? a. 200 b. 1,000 c. 2,000 d. 20,000

c

Which of the following red cell indices support normocytic normochromic red cell morphology? MCV (fL) / MCH (pg) / MCHC (g/dL) a. 120 / 36 / 35 b. 68 / 22 / 28 c. 90 / 30 / 34 d. 75 / 30 / 34

c

Why is it important to have a scrupulously clean hemocytometer when manually counting platelets? a. There are so few platelets, they can be missed if dirt is present b. They are so refractile, they can be confused with dirt c. Their small size makes them easily confused with dirt d. They are easily confused with red cells that are present

c

In the center square on one side of a hemocytometer, 100 platelets were found and 200 were found in the center square on the other side. Select the best course of action. a. Report the count as 150 x 10^9/L b. Verify the count by estimating the platelet number on the smear c. Recount the hemocytometer on a phase microscope d. Repeat the procedure-the two counts are not close enough

d

Interpret the following results (all tests performed manually) on an adult female named Mary Jones. RBC: 3.22 x 10^12 / L Hgb: 16.0 g/dL Hct: 30.0% a. All are normal. b. All are decreased. c. Hemoglobin is elevated and other two are normal. d. Values do not agree with the "rule of three."

d

MCV (fL) = 105 MCH (pg) = 34 MCHC (g/dL) = 35 What red cell morphology would support these calculated red cell indices? a. microcytic hyperchromic red cells b. normocytic hyperchromic red cells c. macrocytic hyperchromic red cells d. There is no red cell morphology that would support these indices.

d

The calculated indices on Mary Jones, whose results are as follows, RBC: 3.22 x 10^12 / L Hgb: 16.0 g/dL Hct: 30.0% are: MCV (fL) / MCH (pg) / MCHC (g/dL) a. 93 / 50 / 53 b. 105 / 29 / 37 c. 93 / 22 / 28 d. 105 / 34 / 35

d