Microhematocrits, Hemoglobin, and RBC Indices Flashcards
Packed cell volume (PVC) is also known as…
 hematocrit (Hct.) 
A quaternary protein, transports oxygen from the alveoli to the tissues of the entire body, and resides in circulating RBCs 
Hemoglobin
The volume of RBCs in a given volume of blood. It is expressed as a percentage of the total blood volume
Hematocrit
What is a classical method of determining the hematocrit
“Spun hematocrit or spun crit”
What is a good estimate of the hematocrit that can be obtained by indirect methods? 
Measuring hemoglobin and multiplying this value by three
Manual hematocrit should be performed within ____ hours After blood collection. 
6
What effect can increased concentration of EDTA (or other Anticoagulants) have? 
Cause shrinking and osmotic crenation of RBCs
Conditions that increase the turbidity of the plasma (lipemia or Leukocytosis), Will affect the results in what way?
Artificially increase the absorbents and yield a falsely high hemoglobin result
What effect will “lyse-Resistant” RBCs have on hematocrit results?
Falsely decreased hemoglobin result
(Hgb C and Hgb S) 
What is the equation for the “rule of three?“?
Hgb x 3 = Target range of Hct (+/-3.0%)
What are two possibilities if the H&H (Hgb and Hct) do not match? 
• there is an instrumentation or operator problem
• The RBCs are abnormal
If the RBCs on a peripheral blood smear appear normal, but the automated H&H values do not match, what should the lab personnel do?
Check to make sure that an error has not occurred
What is the rule of three used to assess?
The integrity of the hemoglobin and/or hematocrit measurements
A “hemogram” consist of what tests? 
WBC count
RBC count
Hemoglobin (Hgb)
Hematocrit (Hct)
MCV
MCH
MCHC
PLT
What are three sophisticated instrumentation Devices that are sometimes added to the hemagram in hospitals?
• RDW (Red cell distribution width)
• MPV (Mean platelet volume)
• PDW (Platelet distribution width) 
Total erythrocyte (RBC) count , Hgb and Hct values are used to determine what three RBC indices?
•mean cell/corpuscular volume (MCV)
•mean cell/corpuscular hemoglobin (MCH)
• mean cell/corpuscular hemoglobin concentration (MCHC)
What is the diagnostic use of the three RBC indices? 
Used in classifying and differentiating anemia‘s
What is the normal MCV value?
80-100 fL (size of cell)
Above is macrocytic, below is microcytic, and normal is normocytic
What is the formula for MCV?
Hematocrit (%) x 10 Divided by
RBC 
What does MCV indicate? And what are the units
Average volume of a single RBC, femtoliters 
What is the normal range for MCH? And what does it indicate?
26-34 pg (picograms)
Average weight of hemoglobin per RBC
If MCH doesn’t correlate with MCV, you have ________________. 
Spherocytes 
What can MCH confirm?
If RBCs are microcytic or macrocytic
What does MCHC stand for?
Mean corpuscular hemoglobin concentration
What is the normal MCHC range? 
And what does it measure?
31-37 g/dL
Average concentration of hemoglobin in each RBC
What is the formula for MCH?
Hemoglobin x 10. Divided by
RBC
What is the formula for MCHC?
Hemoglobin / by hematocrit (%)
X100
What is the term for increased and Decreased MCHC?
Spherocytes (above 37)
Hypochromic
Normochromic
An MCHC value of 33 g/dL Is the same as….
33%
They are equivalent units
Hyperchromic RBCs are actually caused by a shape changed, and thus are only found in….
Scherocytes 
Why should any MCHC value over 37 g/dL The recalculated?
Because normal RBCs can’t hold more Hgb than 37 g/dL
A result of over 37 would mean scherocytes are present 
True or false,
hyperchromic is used as a description of erythrocyte morphology 
False
Elevated MCHC is most likely due to…
Error 
What is the normal RBC adult range?
4.0- 6.0 x10^12L
What is the normal hemoglobin adult range?
12.0-18.0 g/dL
What is the normal adult hematocrit range?
36-53%
Is every RBC that lacks a zone of pallor a spherocyte?
No
Term used when there’s a variety of sizes of the RBC‘s
Aniosocytosis
Term used when there is decrease in hemoglobin for an increase in pallor
Hypochromic
