Question 1

What is the most common reason for blood films having red cells that are gray and white cells that are too dark?&#10;A)overrinsing&#10;B)buffering for too short a time&#10;C)stain or buffer that is too acidic&#10;D)stain or buffer that is too alkaline

Accepted Answer

When the stain or buffer it too alkaline,red cells will be gray and white cells will stain too darkly for good morphologic evaluation.

Question 2

Select the best course of action to remedy blood films that typically are too thick from newborns.&#10;A)Increase the spreader slide angle.&#10;B)Use a larger drop.&#10;C)Dilute the blood with saline.&#10;D)Decrease the spreader slide angle.

Accepted Answer

Decreasing the angle of the spreader slide will make the blood film thinner,as well as longer.

Question 3

Coverslip smears are used primarily for&#10;A)high white blood counts.&#10;B)bone marrow aspirates.&#10;C)finger and heel punctures.&#10;D)polycythemia patients with high red counts.

Accepted Answer

Coverslip smears are used primarily for bone marrow aspirates.They are too fragile to routinely handle when making smears of blood films;they also must be manually stained,which is not practical to do in most laboratories.

Question 4

Clumped platelets will cause which of the following spurious results when cell counts are performed on an automated hematology analyzer?&#10;A)platelets low and white count high&#10;B)platelets high and white count low&#10;C)platelets low and white count unaffected&#10;D)platelets low and hemoglobin high

Accepted Answer

The presence of clumped platelets in blood will cause the platelet count to be low and the white count to be high when performed using an automated analyzer.The clumps of platelets may be of a similar size to white blood cells (WBCs)and the instrument cannot distinguish them as nonwhite cells.

Question 5

Macroscopic holes in a blood film most likely mean the patient has&#10;A)increased blood proteins.&#10;B)red cell agglutination.&#10;C)increased lipids.&#10;D)increased white blood count.

Accepted Answer

Increased lipids in the plasma can cause the appearance of holes all over the blood film.Some of the other hematology parameters should be carefully evaluated because they may also be influenced by the presence of these lipids (e.g.,hemoglobin).

Question 6

A patient's blood film had marked echinocytes and many broken and vacuolated neutrophils.The same patient's blood film the day before did not show these features.Select the best course of action.&#10;A)Report the results.&#10;B)Make a new film.&#10;C)Disregard these findings as artifact.&#10;D)Collect a new sample and make the film within 5 hours.

Accepted Answer

Blood films made from ethylenediaminetetraacetic acid (EDTA)blood that has remained at room temperature for more than 5 hours will often contain the findings noted previously.Slides should ideally be made within 2 to 3 hours of drawing the specimen if good-quality morphology is desired.

Question 7

All of the following can be determined from a blood film except&#10;A)red cell morphology.&#10;B)white cell estimate.&#10;C)red cell estimate.&#10;D)platelet estimate.

Accepted Answer

A red cell count estimate cannot be made from a blood film.White cell and platelet count estimates are routinely made,and red cell morphology is evaluated.

Question 8

How can the correct platelet count on a patient be determined when his or her platelets repeatedly clump in an EDTA specimen?&#10;A)Re-collect in sodium citrate tube (blue top) and multiply by 0.5.&#10;B)Re-collect in sodium citrate tube (blue top) and multiply count by 1.1.&#10;C)Report the estimated number from the blood film.&#10;D)Re-collect in an EDTA tube.

Accepted Answer

When platelet clumping repeatedly occurs in an EDTA blood,the blood should be drawn in a sodium citrate tube.The dilution of blood by the anticoagulant is 9:10 (9 parts blood to 1 part anticoagulant).The platelet count obtained on this tube must therefore be multiplied by the reciprocal of the dilution (10/9)= 1.1.

Question 9

Methods,such as using a fan to dry blood films faster,are especially important when&#10;A)the patient is very anemic or high humidity exists.&#10;B)the patient has polycythemia or high humidity exists.&#10;C)the sample is more than 6 hours old.&#10;D)no one is available to blow on the blood film.

Accepted Answer

When the blood film dries slowly on the slide,red cell and drying artifacts make it extremely difficult to evaluate red blood cell (RBC)morphology.Humidity adds to this problem,as does the high plasma volume found in an anemic patient.Drying the slide with a fan can be beneficial.

Deck 16: Examination of the Peripheral Blood Film and Correlation with the Complete Blood Count