Ch. 14 - RBC Indices Flashcards
Why are the RBC Indices calculated?
To determine the size and hemoglobin content of the average RBC.
For quality control check
To differentiate anemias
What are the RBC Indices?
Mean Cell Volume
Mean Cell Hemoglobin
Mean Cell Hemoglobin Concentration
The RBC indice that is the average volume of the RBC
Mean Cell Volume
What is the unit used to express MCV?
Femtoliters (fL), or 10^-15 L
What is the formula for MCV?
MCV =
Hct (%) x 10/RBC count (x 10^12/L)
What is the reference range for MCV?
80 - 100 fL
What is the term used to describe RBCs with an MCV of less than 80fL?
Microcytic
What is the term used to describe RBCs with an MCV of more than 100fL?
Macrocytic
The RBC indice that is the average weight of hemoglobin in an RBC
Mean Cell Hemoglobin (MCH)
What unit is used to express MCH?
Picograms (pg), or 10^-12 g
What is the formula used to calculate MCH?
MCH =
Hb (g/dL) x 10/RBC count (x 10^12/L)
What is the reference range for MCH for adults?
28 - 32 pg
Which among the RBC indices is not considered in the classification of anemias?
MCH
The RBC indice that is the average concentration of hemoglobin in each individual erythrocyte.
Mean Cell Hemoglobin Concentration (MCHC)
What is the unit used to express MCHC?
Grams per deciliter (formerly given as percentage)
What is the formula used to calculate MCHC?
MCHC =
Hb (g/dL) x 100/Hct (%)
MCHC values of normochromic cells range from _____
32 to 36 g/dL
What are the MCHC values of hypochromic cells?
Less than 32 g/dL
What are the MCHC values of hyperchromic cells?
Greater than 36 g/dL
Among the different types of cells classified under MCHC, which is a misnomer?
Hyperchromic cells
What makes the hyperchromic cells a misnomer?
A cell does not really contain more than 36 g/dL of hemoglobin, but its shape may have become spherocytic, which makes the cell appear full.
Possible error in hemoglobin value
Presence of cold agglutinin
What can be done to produce accurate results for a specimen showing hyperchromic cells due to cold agglutinin?
Incubate the specimen at 37 C for 15 mins.
The following data could be caused by what diseases?
MCV <32
RBC Morphology:
Microcytic; Hypochromic
Iron deficiency anemia Thalassemia Sideroblastic anemia Other condition of defective iron use Chronic infection or inflammation Unstable hemoglobins
The following data could be caused by what diseases? MCV 80 - 100 MCHC 32 - 36 RBC Morphology: Normocytic; Normochromic
Hemolytic anemia Leukemia Metastatic malignancy Bone marrow failure Chronic renal disease
The following data could be caused by what diseases? MCV >100 MCHC 32 - 36 RBC Morphology: Macrocytic; Normochromic
Megaloblastic anemias
Liver disease
Myelodysplasias
What is the RBC morphology of cells with:
MCV <32
Microcytic; Hypochromic
What is the RBC morphology of cells with:
MCV 80 - 100
MCHC 32 - 36
Normocytic; Normochromic
What is the RBC morphology of cells with:
MCV >100
MCHC 32 - 36
Macrocytic; Normochromic
MCV <32 These results can usually be found in the following diseases except: Iron deficient anemia Thalassemia Unstable hemoglobins Myelodysplasias
Myelodysplasias
MCV 80 - 100 MCHC 32 - 36 These results can usually be found in the following diseases except: Hemolytic anemia Leukemia Chronic infection or inflammation Chronic renal disease
Chronic infection or inflammation
MCV >100 MCHC 32 - 36 These results can usually be found in the following diseases except: Megaloblastic anemia Liver disease Sideroblastic anemia
Sideroblastic anemia
