HgB & Hct

Question 1

Also known as Respiratory Pigment

Answer 1

Hemoglobin

Question 2

One of the tests used to diagnose and follow the treatments of anemia.

Answer 2

Hemoglobin

Question 3

What is the main component of hemoglobin?

Answer 3

Red blood cells (95%)

Question 4

In what state does iron bind to oxygen?

Answer 4

Ferrous state or Fe2+

Question 5

The portion that determines the type of
hemoglobin

Answer 5

Globin

Question 6

How many subunits does each Hgb have?

Answer 6

4 heme & 4 globin

Question 7

1 heme is capable of carrying how many moles of O2?

Answer 7

1 mole

Question 8

2 alpha chains/2 beta chains

Answer 8

Hemoglobin A

Question 9

2 alpha chains/2 delta chains

Answer 9

Hemoglobin A2

Question 10

2 alpha chains and 2 gamma chains

Answer 10

Hemoglobin F (1-2%)

Question 11

This is coded by Chromosome 16

Answer 11

Alpha chain

Question 12

Gamma, delta, and beta chains are coded by?

Answer 12

Chromosome 11

Question 13

Types of Abnormal Hemoglobin

Answer 13

Hemoglobin S
Hemoglobin C
Hemoglobin E
Hemoglobin D
Hemoglobin G
Hemoglobin Lepore

Question 14

Hemoglobin whose structures have been modified due to drugs or environmental chemicals

Answer 14

Hemoglobin variants/ Abnormal Hemoglobin Pigmentation/ Dyshemoglobin

Question 15

Can cause increased O2 affinity thus decreasing the efficiency of Oxygen to be delivered to the tissues

Answer 15

Methemoglobin

Question 16

Methemoglobin is caused by?

Answer 16

oxidants (Nitrite, Primaquine,
dapsone, Benzocaine) or Methemoglobin Reductase deficiency

Question 17

Methemoglobin can be treated by

Answer 17

administration of Ascorbic Acid and Methylene Blue

Question 18

Sulfhemoglobin is caused by?

Answer 18

sulfonamides, phenacetin, nitrites,
phenylhydrazine

Question 19

Addition of Hydrogen sulfide to the hemoglobin (greenish pigment) causes

Answer 19

Sulfhemoglobin

Question 20

The only irreversible Abnormal hemoglobin pigmentation

Answer 20

Sulfhemoglobin

Question 21

Caused by the combination of heme and carbon monoxide

Answer 21

Carboxyhemoglobin

Question 22

CO has an affinity to hemoglobin of ____ than that of oxygen

Answer 22

240x

Question 23

Carboxyhemoglobin can be treated by

Answer 23

Oxygen Saturation or
Hyperbaric oxygen therapy

Question 24

This is the reference method approved by the Clinical and Laboratory Standards Institute for Hemoglobin determination.

Answer 24

The cyanmethemoglobin (hemoglobincyanide) method

Question 25

Principle of cyanmethemoglobin (hemoglobincyanide) method

Answer 25

In the cyanmethemoglobin method, blood is diluted in an alkaline Drabkin solution of potassium ferricyanide, potassium cyanide, sodium bicarbonate, and a surfactant.

Question 26

The absorbance of the cyanmethemoglobin is at _____

Answer 26

540 nm

Question 27

The absorbance of the cyanmethemoglobin at 540 nm is directly proportional to?

Answer 27

hemoglobin concentration

Question 28

This cannot be converted to cyanmethemoglobin; it cannot be measured.

Answer 28

Sulfhemoglobin

Question 29

This is the instrument used for Hemoglobin determination

Answer 29

Spectrophotometer

Question 30

The reagent used in Hemoglobin determination

Answer 30

Detergent-modified Drabkin's reagent.

Question 31

Components of Drabkin's reagent

Answer 31

Potassium Cyanide Potassium Ferricyanide Potassium dihydrogen phosphate or sodium bicarbonate Non-ionic compound (improves cell lysis)

Question 32

Potassium ferricyanide:

Answer 32

hemoglobin → methemoglobin

Question 33

Potassium cyanide:

Answer 33

methemoglobin → cyanmethemoglobin

Question 34

The anticoagulant used for Hgb determination

Answer 34

EDTA or Heparin

Question 35

These are resistant to hemolysis, causing turbidity

Answer 35

Cells containing Hb S and Hb C

Question 36

This hemoglobin takes 1 hour to convert to cyanmethemoglobin and theoretically could cause erroneous results in samples from heavy smokers

Answer 36

Carboxyhemoglobin

Question 37

Why do need to be cautious with the hemoglobin reagent?

Answer 37

Because it contains cyanide, which is highly toxic. Acidification of cyanide in the reagent releases highly toxic hydrogen cyanide gas

Question 38

The ratio for reagent to blood in Hgb determination

Answer 38

5 ml or 5000 ul of reagent, 20 ul or 0.02 ml of whole blood.

Question 39

Normal Hemoglobin values

Answer 39

Male: 14-18 g/dL Female: 12-15 g/dL Newborn: 16.5-21.5 g/dL

Question 40

Technical sources of errors for Hgb determination

Answer 40

Pipetting errors Dirty and scratch cuvettes Deteriorated reagent

Question 41

Biologic sources of errors for Hgb determination

Answer 41

Lipemic Sample Leukocytosis Hgb S and Hgb C

Question 42

Refers to the volume of packed red blood cells that occupy a given volume of whole blood.

Answer 42

Hematocrit

Question 43

Hematocrit is often referred to as

Answer 43

packed cell volume (PCV)

Question 44

It is reported either as a percentage (e.g., 36%) or in liters per liter (0.36 L/L).

Answer 44

Hematocrit

Question 45

Anticoagulant used for microhematocrit

Answer 45

EDTA or heparin

Question 46

Two methods for hematocrit testing

Answer 46

Macrohematocrit (uses wintrobe tube) Microhematocrit (uses capillary tube)

Question 47

Normal Hematocrit values

Answer 47

- Male 40-54% (0.40-0.54 L/L) - Female 35-49% (0.35-0.49 L/L) - Newborn 53-65% (0.53-0.65 L/L) - Child 30-43% (0.30-0.43 L/L)

Question 48

The instrument used to determine hematocrit

Answer 48

microhematocrit reader

Question 49

What are the four layers in a hematocrit tube?

Answer 49

Plasma, buffy coat (WBCs & platelets), and RBCs

Question 50

The length of the sealing clay

Answer 50

at least 4 mm long

Question 51

When loading the micro hematocrit centrifuge, the clay ends must be facing the _____ from the center, touching the rubber gasket

Answer 51

outside away

Question 52

How many minutes should you centrifuge the capillary tubes?

Answer 52

Centrifuge the tubes for 5 minutes between the speed of 10,000 g to 15,000 g

Question 53

Factors that cause a false decrease in hematocrit

Answer 53

-Incomplete sealing of tubes -Hemolysis -Over Anticoagulated Blood -Introduction of interstitial fluid from a skin puncture or the improper flushing of an intravenous catheter

Question 54

Factors that cause a false increase in hematocrit

Answer 54

-Reading including the buffy coat -Inadequate centrifugation -Abnormal RBC Morphology: Macrocytic -Anemia, Spherocytosis, Thalassemia, Hypochromic Anemia, Sickle Cell Anemia -Fluid loss associated with dehydration