Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Hematology > Week 4 > Flashcards

Week 4 Flashcards

Reticulocyte Measurement & Automated CBC Analysis

1
Q

Which RBCs are normally found in the peripheral blood?

A

Mature erythrocytes
Reticulocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the nucleus-to-cytoplasm (N:C) ratio in a pronormoblast?

A

The pronormoblast has a high N:C
ratio.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the shape of the nucleus in a pronormoblast?

A

The nucleus is round or oval in shape.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What feature of the chromatin is notable in a pronormoblast?

A

The chromatin is very open in a pronormoblast.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the color of the cytoplasm in a pronormoblast?

A

The cytoplasm is dark blue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where is the pronormoblast typically located in healthy states?

A

The pronormoblast is located in the bone marrow.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the function of the pronormoblast in relation to hemoglobin?

A

The pronormoblast is responsible for producing and accumulating the components required for hemoglobin production.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What ability does the pronormoblast have in terms of cell division?

A

The pronormoblast is able to divide via mitosis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the N:C ratio in a basophilic normoblast?

A

The basophilic normoblast also has a high N:C ratio.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does the chromatin in a basophilic normoblast differ from that of a pronormoblast?

A

In a basophilic normoblast, the chromatin starts to condense.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the appearance of the cytoplasm in a basophilic normoblast?

A

The cytoplasm is a deep, dark blue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Does the basophilic normoblast have nucleoli?

A

Nucleoli may be present in a basophilic normoblast.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Where is the basophilic normoblast located in the body during healthy states?

A

The basophilic normoblast is located in the bone marrow.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What key process related to hemoglobin occurs in the basophilic normoblast?

A

Detectable hemoglobin synthesis occurs in the basophilic normoblast.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What cellular structures are present in the basophilic normoblast?

A

The basophilic normoblast has cytoplasmic organelles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What ability does the basophilic normoblast share with the pronormoblast in terms of cell division?

A

The basophilic normoblast is also able to divide via mitosis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the N:C ratio in a polychromatic normoblast?

A

The N:C ratio evens out, becoming 1:1.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What happens to the chromatin in a polychromatic normoblast?

A

The chromatin condenses further.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What cytoplasmic change is associated with the first stage of hemoglobin accumulation in a polychromatic normoblast?

A

The cytoplasm becomes murky gray-blue as hemoglobin accumulates.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is significant about the polychromatic normoblast’s ability to divide?

A

It is the last stage capable of undergoing mitosis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where is the polychromatic normoblast located in healthy individuals?

A

It is located in the bone marrow.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What synthesis process increases in a polychromatic normoblast?

A

Hemoglobin synthesis increases.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What organelles are still present in the polychromatic normoblast?

A

RNA and organelles are still present.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the N:C ratio in an orthochromic normoblast?

A

The N:C ratio is low.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How is the chromatin in an orthochromic normoblast described?

A

The chromatin is completely condensed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What does the pink cytoplasm in an orthochromic normoblast reflect?

A

It reflects complete hemoglobin production.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the function of the remaining ribosomes and RNA in the orthochromic normoblast?

A

They complete hemoglobin production and will continue to degrade.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Can the orthochromic normoblast undergo cell division?

A

No, it is not capable of division.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Where is the orthochromic normoblast located in healthy individuals?

A

It is located in the bone marrow.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How does hemoglobin production continue in an orthochromic normoblast?

A

It continues using the remaining ribosomes and mRNA.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What significant process happens to the nucleus in the orthochromic normoblast stage?

A

The nucleus and other organelles are ejected late in this stage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What happens if a small fragment of the nucleus is left behind in the orthochromic normoblast?

A

It becomes a Howell-Jolly body.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Does a polychromatic erythrocyte have a nucleus?

A

No, a polychromatic erythrocyte does not have a nucleus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Can a polychromatic erythrocyte divide?

A

No, a polychromatic erythrocyte cannot divide.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Where does the polychromatic erythrocyte move to after the bone marrow?

A

It moves from the bone marrow to the peripheral circulation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is completed in a polychromatic erythrocyte in terms of hemoglobin production?

A

It completes the production of hemoglobin using residual ribosomes and mRNA.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What happens to the cytoplasmic protein production machinery in a polychromatic erythrocyte?

A

The cytoplasmic protein production machinery is being dismantled.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Does a mature erythrocyte have a nucleus?

A

No, a mature erythrocyte does not have a nucleus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Can a mature erythrocyte divide?

A

No, a mature erythrocyte cannot divide.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

How long is a mature erythrocyte found in peripheral circulation?

A

It remains in peripheral circulation for 120 days until removed by the spleen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is the main activity of a mature erythrocyte?

A

The main activity is using the previously produced hemoglobin to deliver oxygen to tissues.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What significant process occurs in the orthochromatic normoblast?

A

The orthochromatic normoblast loses its nucleus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Where is the reticulocyte located for the first 1-2 days of its life, and what is it still producing?

A

The reticulocyte is in the bone marrow (BM) for 1-2 days, still producing hemoglobin (Hgb).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

After leaving the bone marrow, where is the reticulocyte found, and what process continues?

A

The reticulocyte moves to the peripheral blood and continues producing hemoglobin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

How long does it take for the reticulocyte to mature in peripheral blood, and what significant process stops?

A

It matures within about 1 day, and hemoglobin production stops.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What is the main difference between a reticulocyte and an erythrocyte?

A

An erythrocyte is fully mature, with no more hemoglobin production occurring.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What is the average cell diameter of a pronormoblast?

A

Around 12 µm.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

How does the average cell diameter change from the pronormoblast to the reticulocyte stage?

A

It decreases from around 12 µm to approximately 7-8 µm.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

At which stage does RNA synthesis begin to decrease significantly?

A

RNA synthesis begins to decrease during the polychromatic normoblast stage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What happens to the rate of RNA content as the cell matures into a reticulocyte?

A

The RNA content decreases further as the cell matures into a reticulocyte.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

When does DNA synthesis stop in the erythropoiesis process?

A

DNA synthesis stops at the orthochromic normoblast stage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What trend is observed in hemoglobin concentration as the cell progresses from pronormoblast to reticulocyte?

A

Hemoglobin concentration steadily increases as the cell matures.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

At what point does the total protein concentration per cell begin to stabilize?

A

The total protein concentration per cell begins to stabilize during the orthochromic normoblast stage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

How does acidophilia (affinity for acidic dyes) change through erythropoiesis?

A

Acidophilia increases as hemoglobin concentration increases, becoming more prominent in the later stages of erythropoiesis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What condition is commonly associated with an increased reticulocyte count due to red blood cell destruction?

A

Hemolytic anemia.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

How does hemorrhage affect reticulocyte count?

A

Hemorrhage can lead to an increased reticulocyte count as the bone marrow responds to blood loss.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What does an increased reticulocyte count indicate in the context of treated iron deficiency anemia (IDA) and megaloblastic anemia?

A

It indicates a healthy bone marrow response to treatment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What condition associated with kidney function can also result in an increased reticulocyte count?

A

Uremia.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What does an increased reticulocyte count generally indicate about bone marrow function?

A

It indicates a healthy bone marrow response.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What are two conditions associated with ineffective erythropoiesis and a decreased reticulocyte count?

A

Pernicious anemia and sideroblastic anemia.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What are two conditions that result in a decreased reticulocyte count due to bone marrow failure?

A

Aplastic crisis and aplastic anemia.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What is the characteristic color of reticulocytes on a Wright’s stained smear?

A

Reticulocytes have a bluish hue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

How does the appearance of reticulocytes differ from mature red blood cells in terms of central pallor?

A

Reticulocytes have no central pallor.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

How does the size of reticulocytes compare to mature red blood cells?

A

Reticulocytes are slightly macrocytic (larger).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

How are reticulocytes reported on a Wright’s stained smear?

A

They are reported as increased polychromasia.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What type of stain is used in a manual reticulocyte count?

A

A supravital stain.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What is the purpose of using a supravital stain in reticulocyte counts?

A

To stain cells while they are still alive.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

Which dyes are commonly used for supravital staining of reticulocytes?

A

New Methylene Blue or Brilliant Cresol Blue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What happens to the reticulum in a reticulocyte when stained with supravital dye?

A

The reticulum is precipitated as a dye-protein complex.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

If 15 reticulocytes are counted out of 1000 RBCs, what is the relative reticulocyte percentage?

A

The relative reticulocyte percentage is 1.5%:

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

If a patient’s reticulocyte count is 2% and the RBC count is 2.20 × 10¹²/L, what is the Absolute Reticulocyte Count (ARC)?

A

The ARC is 44 × 10⁹/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

What can cause refractive artifacts in RBCs during a reticulocyte count?

A

Refractive artifacts are caused by moisture in the air and poor drying of the slide.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

How does poor mixing affect reticulocyte counting?

A

Poor mixing can cause reticulocytes to float, leading to inaccurate counts.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

What are common errors in counting reticulocytes?

A

Common errors include missing or double counts of reticulocytes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

What other RBC inclusions can be mistaken for reticulocytes during supravital staining?

A

Howell-Jolly bodies, Heinz bodies, and Pappenheimer bodies.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

What is a common source of error in reticulocyte counting involving Howell-Jolly bodies?

A

Howell-Jolly bodies can stain supravitally and be mistaken for reticulocytes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

How can Heinz bodies be observed on a Wright-stained preparation?

A

Heinz bodies can be observed as “bite cells” on a Wright-stained preparation due to removal of the inclusions by the spleen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

What is the difference between a reticulocyte and a Heinz body in supravital staining?

A

Reticulocytes show a reticulated network of RNA, while Heinz bodies appear as dark, singular inclusions at the cell periphery.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

What do reticulocytes and basophilic stippling have in common?

A

Both consist of RNA filaments and protein.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

How are reticulocytes characterized in terms of RNA appearance?

A

Reticulocytes show a “rope with multiple tied knots” formation of RNA.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

What is the appearance of basophilic stippling in red blood cells?

A

Basophilic stippling appears as fine or coarse granules evenly distributed throughout the cytoplasm.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

How do you differentiate between reticulocytes and cells with basophilic stippling?

A

Reticulocytes have a distinct network-like RNA structure, while basophilic stippling consists of granules dispersed evenly throughout the cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

Why is a correction needed for the reticulocyte count in specimens with low hematocrit (Hct)?

A

In low Hct specimens, the reticulocyte percentage may be falsely elevated because the whole blood contains fewer RBCs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

What value is used as the normal hematocrit in the corrected reticulocyte count formula?

A

The normal hematocrit value used is 0.45 L/L.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

What does the corrected reticulocyte count help to adjust for?

A

It adjusts for variations in hematocrit to provide a more accurate reticulocyte count.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

What formula is used to calculate the Corrected Reticulocyte Count?

A

retic (%) x (patient HCT/0.45)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

How is the relative reticulocyte count (%) calculated?

A

(number of retics x 100)/1000

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

How is the Absolute Reticulocyte Count (ARC) calculated?

A

(retic % x RBC count)/100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

What are reticulocytes called when they are pushed into peripheral blood early due to hemolytic anemia?

A

They are called “shift” retics.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

What does the Reticulocyte Production Index (RPI) help assess in bone marrow (BM) response?

A

It helps assess how many new RBCs are released daily.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

How do “shift” reticulocytes affect the reticulocyte count?

A

They skew the picture by being counted for several days, making the reticulocyte count appear higher.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

How long do immature reticulocytes (shift retics) take to mature?

A

Immature reticulocytes take approximately 2.5 days to mature.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

What is the maturation correction factor for a patient with a hematocrit of 40–45%?

A

The correction factor is 1 day.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

What is the maturation correction factor for a hematocrit value of 25–34%?

A

The correction factor is 2 days.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

How is the Reticulocyte Production Index (RPI) calculated?

A

corrected retic count/maturation time (days)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

If a patient has a reticulocyte count of 7.8%, a hematocrit of 0.30 L/L, and a maturation time of 2 days, what is the RPI?

A

The RPI is 2.6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

What is the maturation correction factor for a patient with a hematocrit of 15–24%?

A

The correction factor is 2.5 days.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

What does the Reticulocyte Production Index (RPI) represent?

A

The RPI is a calculation used to assess bone marrow response.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

What does an RPI greater than 3 indicate?

A

An RPI greater than 3 indicates a good marrow response.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
100
Q

What does an RPI less than 2 indicate?

A

An RPI less than 2 indicates an inadequate marrow response.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
101
Q

What type of blood sample is used for an automated reticulocyte count?

A

Whole blood is analyzed on a cell counter.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
102
Q

How are reticulocytes measured in an automated reticulocyte count?

A

Reticulocytes are measured by flow cytometry.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
103
Q

What substances are mixed with the blood sample to measure reticulocytes using flow cytometry?

A

The blood is mixed with fluorescent dyes or nucleic acid stains.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
104
Q

What type of measurement does the analyzer use to detect reticulocytes?

A

The analyzer measures optical scatter or fluorescence.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
105
Q

What might be required in some models of automated reticulocyte counters before aspiration?

A

Some models require pre-aspiration preparation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
106
Q

What are the two main flow cytometry methods used in an automated reticulocyte count?

A

Optical scatter and fluorescence method.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
107
Q

What substance is added to the blood in the fluorescence method for reticulocyte counting?

A

Auramine O is added to the blood.

108
Q

How is RNA content related to fluorescence detection in reticulocyte counting?

A

The higher the RNA content, the more fluorescence is detected.

109
Q

What is the purpose of using flow cytometry in reticulocyte counts?

A

To measure reticulocyte presence based on light scattering and fluorescence, providing detailed information about their RNA content.

110
Q

What is a key advantage of automated reticulocyte counting compared to manual methods?

A

It is faster than manual counting.

111
Q

Why is automated reticulocyte counting more precise and accurate?

A

It eliminates slide distribution errors, reducing the chance of technical mistakes.

112
Q

How does automation reduce variability in reticulocyte counts?

A

Automation results in less variability between technologists, leading to more consistent results.

113
Q

Why is automated reticulocyte counting considered more objective?

A

It provides greater objectivity by using standardized machine-based measurements.

114
Q

How does the number of cells counted in automated reticulocyte counting contribute to its accuracy?

A

A large number of cells are counted, improving the statistical accuracy of the results.

115
Q

What standardized aspect of automated counting contributes to its accuracy?

A

Standardized methods of detection ensure that results are consistent and reliable.

116
Q

What is replacing the Reticulocyte Production Index (RPI) in automated reticulocyte counts?

A

The Immature Reticulocyte Fraction (IRF) is replacing the RPI.

117
Q

What does the Immature Reticulocyte Fraction (IRF) measure?

A

The IRF measures the ratio of immature reticulocytes to total reticulocytes in a sample.

118
Q

How can automated analyzers differentiate immature reticulocytes from older ones?

A

By the amount of fluorescence detected, as immature reticulocytes have more RNA.

119
Q

Why do newer reticulocytes show more fluorescence?

A

Because they contain more RNA, which produces more fluorescence during the analysis.

120
Q

What does the IRF indicate in terms of bone marrow response?

A

A higher IRF indicates an active bone marrow response, as more immature reticulocytes are being released.

121
Q

What does the Reticulocyte Hemoglobin Concentration assess?

A

It assesses the response to Iron Deficiency Anemia (IDA) treatment.

122
Q

What are examples of Reticulocyte Indices used in automated analysis?

A

Reticulocyte indices include the mean reticulocyte volume and reticulocyte distribution width.

123
Q

Why are Reticulocyte Hemoglobin Concentration and Reticulocyte Indices important in clinical settings?

A

They provide more meaningful analyses to determine bone marrow response to EPO (erythropoietin) treatment or iron therapy.

124
Q

What are the key components of Quality Assurance in the Hematology Lab?

A

Daily validation of methods and equipment

Detailed SOPs (Standard Operating Procedures) with sources of error

Reflex/confirmation testing

125
Q

What is a requirement for a laboratory operator to be validated in the Hematology Lab?

A

The operator must be a Licensed Medical Laboratory Technologist (MLT).

126
Q

Which professional organization must a licensed MLT be a member of in good standing?

A

The CMLTO (College of Medical Laboratory Technologists of Ontario).

127
Q

Where must an operator be trained to be validated as an MLT?

A

At an accredited Medical Laboratory Science (MLS) program, such as Michener.

128
Q

What training is necessary for an operator to be validated on laboratory analyzers?

A

The operator must be properly trained on the analyzer and proficient in the methods used for testing.

129
Q

What ongoing requirement must operators meet to maintain their validation?

A

They must participate in Continuing Education.

130
Q

What is an essential component of analyzer validation regarding Quality Control (QC)?

A

Run and assess QC regularly, including manufacturer’s QC once per shift and patient QC samples at regular intervals.

131
Q

How often should the manufacturer’s QC be run on an analyzer?

A

Once per shift.

132
Q

What tool is used to monitor and check the quality control system in analyzer validation?

A

Westgard rules.

133
Q

What kind of alerts should be monitored during analyzer validation?

A

Alerts for reagents and electronics should be monitored.

134
Q

What is the proper volume requirement for a hematology specimen?

A

The specimen should be within 10% of the stated draw volume to avoid false results and improper mixing.

135
Q

Why is EDTA used as an anticoagulant in hematology samples?

A

EDTA chelates calcium, inhibiting clotting and preserving cellular components and morphology for assessment.

136
Q

What is the time frame for analyzing an EDTA specimen to maintain its integrity?

A

EDTA specimens should be analyzed within six hours of collection and stored at room temperature until analysis is complete.

137
Q

What happens to blood cells if an EDTA specimen is stored for too long?

A

Red cells swell, platelets degenerate, and WBCs are affected, which impacts the reliability of the results.

138
Q

What are the requirements for proper specimen procurement?

A

The specimen must be mixed properly and should not have any trauma to avoid hemolysis.

139
Q

Why is it important to maintain consistent specimen validation results day-to-day?

A

Consistent results ensure reliable and accurate diagnostic data for patient care.

140
Q

What are common causes of false or ‘impossible’ results in hematology testing?

A

False or impossible results are often due to issues with the blood related to patient condition.

141
Q

What is the first check in the validation of results to ensure accuracy?

A

The Rule of Three or H/H check, which ensures the relationship between hemoglobin, hematocrit, and RBC count is within normal ranges.

142
Q

Why are counts checked within linearity limits during result validation?

A

To ensure that analyzer counts fall within the range of linearity for the equipment, confirming the reliability of the results.

143
Q

What should be done if an analyzer flag is raised during testing?

A

The flagged result should be reviewed and investigated as it indicates potential issues that may require retesting or manual verification.

144
Q

What are examples of ‘nonsense’ results that should trigger a recheck?

A

Results like MCV > 130 or greatly increased MCH/MCHC indicate potential errors that need further validation.

145
Q

What is the first step in the workflow of a Hematology Lab?

A

Check LIS order to verify the test request.

146
Q

What aspects of the specimen should be validated in the Hem Lab?

A

Label
Volume
Appearance (check for hemolysis, clots, lipemia if obvious)

147
Q

What should be checked regarding the analyzer in the Hem Lab?

A

QA (Quality Assurance) including maintenance and reagent check
QC (Quality Control) to ensure the accuracy of results

148
Q

After prioritizing work, what is the next step in the Hem Lab workflow?

A

Run the sample on the analyzer.

149
Q

What steps should be taken when reviewing sample results in the Hem Lab?

A

Check for flags and abnormal results
Compare with previous results
Repeat abnormal samples
Make peripheral blood smears (PBS)
Perform confirmation tests

150
Q

What should be done when reporting results, especially with stat or critical values?

A

Phone the results if stat or critical values are found.

151
Q

Which parameters are directly measured on analyzers?

A

WBC Total Count and DIFF
RBC
PLT (Platelet)
Hemoglobin (Hgb)
PLT volume / MCV on newer analyzers

152
Q

How is Hematocrit (HCT) calculated on the Michener AcT5diff AL analyzers?

A

HCT (L/L) = [RBC (10^12/L) × MCV (10^-15L)]

153
Q

What is the formula for calculating MCH?

A

MCH (pg) = [Hb (g/L) / RBC (10^12/L)]

154
Q

How is MCHC calculated?

A

MCHC (g/L) = [Hb (g/L) / HCT (L/L)]

155
Q

How is RDW-CV (Red Cell Distribution Width - Coefficient of Variation) derived?

A

RDW-CV is derived from the RBC histogram.

156
Q

How are WBC absolute counts calculated?

A

WBC Absolute counts are derived from the DIFF and Total WBC counts.

157
Q

What is the basic principle behind impedance in blood cell counting?

A

Blood cells suspended in a conductive liquid pass through an aperture, altering the current between two electrodes, which is measured to count and size the cells.

158
Q

What happens to the aperture current when a blood cell passes through it during impedance measurement?

A

The current decreases as the cell passes through, creating a measurable voltage pulse proportional to the cell size.

159
Q

What does the oscilloscope display in the impedance principle?

A

The oscilloscope displays voltage pulses corresponding to the size of the blood cells as they pass through the aperture.

160
Q

What is the role of absorbance in the Beckman Coulter Act5 Diff Counter?

A

The Act5 uses a tungsten halogen lamp for absorbance measurements, with new technology utilizing laser optical scatter to detect cells.

161
Q

What is detected by forward scatter (FS) in the Beckman Coulter Act5 Diff Counter?

A

Forward scatter (0°) detects cell volume or size.

162
Q

What does side scatter (SS) measure in the Beckman Coulter Act5 Diff Counter?

A

Side scatter (90°) measures internal cell complexity, such as granules and vacuoles.

163
Q

What does cytochemistry in the Beckman Coulter Act5 Diff Counter involve?

A

Cytochemistry uses Diff Fix containing Chlorazole black, which stains the granules of neutrophils, lymphocytes, monocytes, and eosinophils.

164
Q

How is cell volume measured in the Beckman Coulter Act5 Diff Counter?

A

Cell volume is measured using focused flow impedance, which detects changes in resistance as a cell passes through the flow cell aperture.

165
Q

What are the characteristics of lymphocytes in the WBC Diffplot?

A

Small volume, low complexity/absorbance.

166
Q

How are neutrophils represented in the WBC Diffplot?

A

Medium volume, moderate complexity.

167
Q

What distinguishes monocytes in the WBC Diffplot?

A

Large volume, low complexity.

168
Q

How are eosinophils characterized in the WBC Diffplot?

A

Medium volume, high complexity.

169
Q

What is measured in the first dilution bath?

A

Hemoglobin.

170
Q

How is hemoglobin measured in the first dilution bath?

A

Hemoglobin is converted to cyan methemoglobin, which is measured spectrophotometrically at 540 nanometers.

171
Q

What could interfere with the spectrophotometric reading of hemoglobin?

A

Lipemic samples or high WBC count can increase turbidity, affecting the accuracy of the spectrophotometric reading.

172
Q

What components are counted in the RBS/Plt bath?

A

Red blood cells, platelets, and white blood cells (WBCs).

173
Q

Why don’t WBCs interfere with the counting in the RBS/Plt bath?

A

WBCs are present in such small numbers that they usually do not interfere.

174
Q

What volume range is used to count red blood cells (RBCs) in the RBS/Plt bath?

A

RBCs are counted in the range between 30–300 fL.

175
Q

What volume range is used to count platelets in the RBS/Plt bath?

A

Platelets are counted up to 18 fL.

176
Q

What can cause a falsely increased RBC count?

A

Very high WBC counts or giant platelets entering the 30 fL region of the histogram, causing them to be counted as red blood cells.

177
Q

How can very high WBC counts falsely increase MCV?

A

High WBC counts can affect hematocrit and RBC counts, causing MCV to be falsely increased due to the inclusion of small red blood cell fragments or clumping of RBCs.

178
Q

What can cause a falsely decreased MCV?

A

Giant platelets being counted as small red cells, leading to a skewed MCV calculation.

179
Q

What does a tight Red Cell Distribution Width (RDW) of 11.4% indicate?

A

Most cells are a uniform size, suggesting decreased anisocytosis.

180
Q

What does a large RDW value (e.g., 27.8%) indicate?

A

A large difference between the smallest and largest cells, indicating increased anisocytosis.

181
Q

What does an RDW of 16.1% suggest?

A

A moderate variation in red blood cell size, showing some anisocytosis.

182
Q

How does RDW relate to anisocytosis?

A

A higher RDW indicates more variation in red blood cell size, which corresponds to increased anisocytosis.

183
Q

What is added to the WBC/BA bath and why?

A

Lyse is added to remove red blood cells and partially lyse WBCs, except for basophils, which are resistant to lyse.

184
Q

What is reported from the WBC/BA bath?

A

The total WBC count and basophils.

185
Q

What could cause false cell counts in the WBC/BA bath?

A

Nucleated red blood cells (NRBCs) can cause false counts as they are resistant to lyse and can be counted as WBCs.

186
Q

What is measured in the WBC Bath histogram?

A

The total WBC count and basophils.

187
Q

What happened to the RBCs and platelets in the WBC Bath?

A

Red blood cells were lysed, and platelets are too small to register on the histogram since platelets are usually under 20 fL.

188
Q

What is added to the DIFF Bath and why?

A

Diff fix is added to the DIFF Bath. The red blood cells are lysed, and the white blood cells are fixed or stabilized. Diff fix differentially stains lymphocytes, monocytes, neutrophils, and eosinophils.

189
Q

What components are counted in the DIFF Bath?

A

Neutrophils, lymphocytes, monocytes, and eosinophils are counted. Red blood cells can interfere and be counted as small lymphocytes if present in large enough numbers.

190
Q

How is the WBC count determined in the DIFF Bath?

A

The WBC count is determined by electrical impedance and compared with the count from the WBC/BASO bath.

191
Q

What happens if the WBC counts from the DIFF Bath and WBC/BASO Bath do not match?

A

The instrument generates a “Diff+/-“ flag if the counts do not match.

192
Q

Where does the 5-part WBC differential come from?

A

The 5-part WBC differential is obtained from the combined results of the WBC/BASO Bath and the DIFF Bath.

193
Q

What parameters are affected by lipemia?

A

HGB increases, MCH increases.

194
Q

Why does lipemia affect the HGB parameter?

A

Turbidity from lipemia affects the spectrophotometric reading for hemoglobin.

195
Q

What is the corrective action for lipemia affecting HGB results?

A

Plasma replacement is the corrective action.

196
Q

What parameters are affected by high WBCs (greater than 100,000/µL)?

A

HGB increases, RBC increases, HCT is incorrect.

197
Q

Why does a high WBC count affect HGB and RBC parameters?

A

Turbidity affects the spectrophotometric reading for HGB, and WBCs are counted along with RBCs.

198
Q

What corrective action should be taken for high WBCs?

A

Perform a manual HCT and HGB, correct RBC count, and if WBC count is above linearity, dilute for correct WBC count.

199
Q

What parameters are affected by cold agglutinins?

A

RBC decreases, MCV increases, MCHC increases, grainy appearance.

200
Q

What is the rationale for the changes in parameters due to cold agglutinins?

A

Agglutination of RBCs causes these changes.

201
Q

What are the instrument indicators for cold agglutinins?

A

Dual RBC population on the RBC map, or a right shift on the RBC histogram.

202
Q

What is the corrective action for cold agglutinins?

A

Warm the specimen to 37°C and rerun the test.

203
Q

What parameters are affected by platelet clumps?

A

Platelet count decreases (PLT ↓) and WBC count increases (WBC ↑).

204
Q

What is the rationale for the changes caused by platelet clumps?

A

Large clumps are counted as WBCs and not as platelets.

205
Q

What are the instrument indicators for platelet clumps?

A

Platelet clumps/N flag, interference at the noise-lymphocyte interface on histogram/cytogram.

206
Q

What is the corrective action for platelet clumps?

A

Redraw specimen in sodium citrate and multiply the result by 1.1.

207
Q

What parameters are affected by nucleated RBCs in older instruments?

A

WBC count is falsely increased (WBC ↑).

208
Q

What is the rationale for the error caused by nucleated RBCs?

A

Nucleated RBCs or micromegakaryoblasts are counted as WBCs.

209
Q

What are the instrument indicators for nucleated RBCs?

A

Nucleated RBC flag resulting from interference at the noise-lymphocyte interface on histogram/cytogram.

210
Q

What is the corrective action for nucleated RBC interference in newer instruments?

A

Newer instruments eliminate this error and count nucleated RBCs correctly, adjusting the WBC count. Manually count micromegakaryoblasts per 100 WBCs and correct.

211
Q

What parameters are affected by microcytes or schistocytes?

A

RBC ↓, PLT ↑

212
Q

What is the rationale for changes in parameters caused by microcytes or schistocytes?

A

The volume of RBCs or RBC fragments is less than the lower RBC threshold and/or within the PLT threshold.

213
Q

What are the instrument indicators for microcytes or schistocytes?

A

Left shift on RBC histogram, MCV flagged if less than limits, and abnormal PLT histogram may be flagged.

214
Q

What is the corrective action for microcytes or schistocytes detected in instrument readings?

A

Review the blood film.

215
Q

What is the Rule of 3 in hematology?

A

Under normal conditions, the hematocrit (Hct) should be 3x the hemoglobin (Hgb) value (± 3).

216
Q

What is the Rule of 3 formula?

A

3 x Hgb / 1000 = Hct ± 0.03 L/L

217
Q

What types of erythrocytes does the Rule of 3 apply to?

A

The Rule of 3 applies only to specimens with normocytic/normochromic erythrocytes.

218
Q

What can a failed Rule of 3 indicate?

A

A failed Rule of 3 can indicate abnormal RBCs or be the first indicator of sample integrity errors.

219
Q

What should you do if the Rule of 3 is acceptable?

A

If the Rule of 3 is acceptable, carry on with validation.

220
Q

What should you do if the Rule of 3 fails?

A

If the Rule of 3 fails, investigate further for potential issues.

221
Q

What is the next step after obtaining CBC and DIFF results?

A

Check all parameters and assess the values.

222
Q

What are the key criteria to check for in CBC and DIFF values?

A

Reference intervals, action limits, delta checks, and linearity limits.

223
Q

What flags might be present in CBC and DIFF results?

A

H/L, HH/LL, V or R or *, ++++ or missing parameters, and nonsense results.

224
Q

What should be done if “nonsense results” are found in the CBC and DIFF values?

A

Investigate for potential issues such as sample integrity, instrument malfunction, or calculation errors.

225
Q

What is the linearity range for WBC (White Blood Cell Count)?

A

0.4 - 120 x 10⁹/L

226
Q

What is the linearity range for RBC (Red Blood Cell Count)?

A

0.3 - 8.0 x 10¹²/L

227
Q

What is the linearity range for platelets?

A

10 - 1000 x 10⁹/L

228
Q

What is the linearity range for hemoglobin?

A

13 - 240 g/L

229
Q

What is the linearity range for hematocrit?

A

0.2 - 0.67 L/L

230
Q

Why are linearity limits important in CBC testing?

A

They define the range within which the method provides accurate and reliable results.

231
Q

What is the purpose of a delta check in a clinical setting?

A

To compare the current result with the most recent previous analysis for the same patient.

232
Q

In what situations might a delta check fail?

A

A significant intervention (e.g., transfusion, surgery) or a profound change in the patient’s condition.

233
Q

What does a failed delta check with no real explanation potentially indicate?

A

It may indicate an analytical error or a mislabeled specimen, requiring investigation.

234
Q

Why are delta checks not typically used in the Michener setting?

A

Because it is assumed that all patients are new and this is their first analysis.

235
Q

What should be done if a delta check fails?

A

The failed delta check must be investigated to rule out errors or specimen mislabeling.

236
Q

What should a normal RBC histogram display?

A

It should have a normal curve and start & finish at the baseline.

237
Q

What is indicated by distinct populations on a diffplot?

A

The distinct populations correspond to neutrophils, eosinophils, lymphocytes, and monocytes with clear separation.

238
Q

What does it mean if the histogram curve doesn’t finish at the baseline?

A

It may indicate abnormalities in cell populations or issues with the sample.

239
Q

What are the two types of flags and messages that can be displayed on a CBC printout?

A

Analytical/Instrument flags and Interpretative messages

240
Q

What should be done when Analytical/Instrument flags or Interpretative messages appear on a CBC printout?

A

Both should be investigated and confirmed before the related parameter can be reported.

241
Q

What is the reporting rule when the Rule of 3 is acceptable, and there are no flags or messages?

A

Report all automated CBC and differential directly from the AcT5 results.

242
Q

What action should be taken if the Rule of 3 is acceptable, but action limit flags (HH or LL) or NRBC flags are present?

A

Refer to the specific parameter(s) in the chart in conjunction with the Suspect Flag Chart.

243
Q

What should be done if the Rule of 3 is unacceptable, or there are other major flags such as a WBC count greater than 100 x 10⁹/L?

A

Hold all automated results until the PBS is examined, validate results by re-running the sample or requesting a new one, and refer to the suspect flag chart.

244
Q

Why is it important to check the tail of a PBS during CBC comparison?

A

To look for fibrin deposits and platelet clumps.

245
Q

What is the first step in CBC & PBS comparison for WBC-related parameter flags?

A

Start with a WBC estimate.

246
Q

What should be done after estimating WBC during a CBC & PBS comparison?

A

Scan the smear for the WBC population and compare it with the Automated Differential.

247
Q

When should a manual differential be performed in a CBC & PBS comparison?

A

If NRBC or early WBC are present, or if you are unsure that the Auto Differential ‘matches.’

248
Q

How should WBC counts be corrected in CBC & PBS comparisons?

A

Correct WBC for NRBC if necessary.

249
Q

What should be done if a Manual Differential is performed during a CBC & PBS comparison?

A

Calculate the Absolute Differential.

250
Q

When can the automated differential be reported?

A

If each parameter of the automated differential is within 10% of the manual differential.

251
Q

What additional step is performed for WBCs during CBC & PBS comparison?

A

Perform WBC morphology.

252
Q

What is the first step in CBC & PBS comparison for platelet-related parameter flags?

A

Start with a PLT estimate.

253
Q

What should be noted during a CBC & PBS comparison for platelet-related flags?

A

Note abnormal platelet morphology.

254
Q

How do you correlate abnormal platelet findings in a CBC & PBS comparison?

A

Correlate with the platelet histogram.

255
Q

What should you start with in a CBC & PBS comparison for RBC-related parameter flags?

A

Start with HGB & HCT first.

256
Q

What should you examine in RBCs during CBC & PBS comparison?

A

Examine color and size of RBCs, and compare with RBC indices & RDW.

257
Q

How should the RBC histogram be used in CBC & PBS comparison?

A

The RBC histogram should correlate with MCV, RDW, and PBS.

258
Q

What should you report in a CBC & PBS comparison for RBCs that automated analyzers may not pick up?

A

Report morphology such as poikilocytosis, intracellular parasites, and inclusions.

259
Q

What is the reflex test if increased polychromasia is noted on the PBS?

A

Reticulocyte count.

260
Q

What condition is indicated by hypochromic/microcytic anemia on PBS, and what is the reflex test?

A

Condition: Hypochromic/Microcytic anemia.
Reflex test: Iron studies.

261
Q

What is the reflex test if sickle cells are observed on PBS?

A

Sickle screen.

262
Q

What does N/N anemia with targets, folded cells, crystals, and sickles indicate, and what test should be performed?

A

Hemoglobin electrophoresis.

263
Q

What test should be performed if spherocytes are noted on PBS?

A

Osmotic fragility test.

264
Q

What is the reflex test if both spherocytes and polychromasia are observed on PBS?

A

Direct Antiglobulin Test (DAT).

265
Q

What should be tested if bite or blister cells are noted on PBS?

A

G6PD Assay.

Hematology (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions