Laboratory evaluation of Red Blood Cells Flashcards
What is in a CBC for RBC?
Erythrocyte count (RBC)
Hemoglobin (Hgb or Hb)
Hematocrit (Hct)
Red Cell Indices- go with size and volume of cells
Whats in a red cell indices?
4
go with size and volume of cells MCV MCH MCHC RDW- lot of different sizes and shapes of cells. high when there is high variation
What other kind of tests can we look at RBC besides a CBC?
3
- Morphology
- Reticulocyte count- young cells(bigger still have some nucleus)
- Bone Marrow Aspiration/Biopsy
What is a Erythrocyte count (RBC) and what are the normal values
Number red blood cells per unit volume of whole blood
Normal values
Female: 4.2 to 5.4x 106 RBCs/µL
Male: 4.7 to 6.1 x 106 RBCs/µL
When does the erythrocyte count (RBC) decrease?
3
Anemia, which can be caused by:
Hemorrhage
Sickle Cell
Dietary deficiency, i.e. iron or B-12
When can erythrocyte count increase?
5
Increased when too many are made and with fluid loss: Higher altitudes Diarrhea Dehydration Burns Pregnancy
What does Hemoglobin (Hgb or Hb) measure?
Measures concentration of hemoglobin in anticoagulated (or capillary) whole blood
Grams of Hb/100mL whole blood
g/dL
Measures the amount of oxygen-carrying protein in the blood.
Reflects the number of RBC’s
What are the normal hemoglobin values for:
newborns?
females?
males?
Normals
Newborns: 14 to 20 g/dL
Female: 12 to 16 g/dL
Male: 13.5 to 18 g/dL
In what situations does hemoglobin decrease?
7
Anemia Hemorrhage Nutritional deficiency Renal disease Cancers Pregnancy --Due to expanded blood volume Certain drugs --Antibiotics, ASA, sulfonamides
What does hemoglobin increase with?
6
Increases with Polycythemia vera COPD CHF High altitudes Severe burns Dehydration
What does our hemocrit value tell us?
Packed cell volume (%)
Percentage of the total blood volume that is made up by RBC’s
What are the normal values for hemocrit?
Normal values
Female 37 to 47%
Male 42 to 52%
What would our hemocrit decrease with?
9
Anemia Hemorrhage Dietary Deficiency Bone marrow failure Pregnancy Malnutrition Leukemia Cirrhosis Hyperthyroidism
What would our hemocrit increase with?
7
Increases with: Congential heart disease Polycythemia vera Dehydation Erythocytosis Eclampsia Burns COPD
Acute blood loss (anemia) is characterized by what?
low blood volume and low RBC
shows a normal HCT though
Chronic anemia is characterized by what?
High blood volume and low RBC levels (low HCT)
Non-anemic low hemocrit is caused by what?
volume overlaod
-normal RBC level and really high blood volume
How do we calculate Mean cell colume or MVC?
What does it measure?
MCV (fL) = (Hct/RBC) X 10
Example: MCV = (41/4.6) x 10 = 89 fL
Measure of the average volume, or size, of a single RBC
How do we interpret MVC?
3
Interpretation
Normocytic 80 to 97 fL
Microcytic 97 fL
What is the MCV the go to lab for?
for determining the types of anemia
When the MCV is increased the cell is said to be? And what is this caused by?
When increased value, the RBC is said to be abnormally large – Macrocytic
- B-12 deficiency
- Folic acid deficiency
Same for MCH
When the MCV is decreased the cell is said to be? and what is this caused by?
When decreased value, the RBC is said t be abnormally small – Microcytic
- Iron deficiency
- Thalassemia
Same for MCH
Neurological symtpoms are always associated with what kind of anemia?
B12
How do you calculate the Mean cell hemoglobin (MCH?
MCH = (Hgb/RBC) X 10
Example: MCH = (13.7/4.6) x 10 = 29.8 pg
What is the MCH a measurement of ?
Measurement of the average amount (weight) of hemoglobin with a RBC
What are the normal values for MCH?
Normal values: 27 to 32 pg
How would you calculate the MCHC (mean cell hemoglobin concentration)?
MCHC = (Hgb/Hct) X 100
Example: MCHC = (13.7/41) x 100 = 33.4%
What does the mean cell hemoglobin concentration (MCHC) measure?
Measure of the average concentration or percentage of hemoglobin within a single RBC
What are the normal values/interpretation for MCHC?
Interpretation
Normochromic: 32 to 36%
Hypochromic:
Decreased values of MCHC indicate what?
What can this be caused by?
2
the cell has a deficiency of hemoglobin and is said to be Hypochromic (lacking color- heme molecule)
Iron deficiency anemia
Thalassemia
With normal MCHC values the anemia is said to be what?
Normocytic
Hemolyic anemia
What can blood cells not be considered?
RBC’s cannot be considered hyperchromic
Only 37g/dl or hemoglobin can fit into the RBC
What is RDW?
And what are its normal lab values?
Red cell distribution width (RDW)
An indication of the variation in the RBC size
Normal values (instrument dependent) Typical range: 11.5 to 14.5%
What is the RDW an indicator of?
What can cause this?
5
an indicator of the degree of anisosytosis, a blood condition characterized by RBC’s of variable and abnormal size
Iron deficiency anemia B12 or Folate deficiency anemia Sickle cell disease Hemolytic anemias Post-hemorrhagic anemias
What test do we do for erythrocyte morphology?
blood smear
What is a normal erythrocyte called?
discocytes
Terms which describe cells color which is proportional to cell Hgb concentration
3
Normochromic
Normocytic
Polychromatophilic
Terms that describe cell size?
4
Normocytic
Microcytic
Macrocytic
Anisocytosis
Descriptive cell names used to describe variations in shape?
poikilocytosis
What labs measure RBC production?
2
Reticulocyte count
Erythropoietin level
What does a full CBC with a diff test?
9
Red cell analyses White blood cell count Differential white cell counts Relative & Absolute neutrophil count Relative & Absolute lymphocyte count Relative & Absolute monocyte count Relative & Absolute basophil count Relative & Absolute eosinophil count Platelet count and indices
What are the applications of a reticulocyet count?
3
- Evaluate pathophysiology of anemia
- Gives an indication of RBC production by the bone marrow and
- can assess erythropoietic response to anemia and therapy
What does a bone marrow biopsy evaluate?
hematopoiesis
What does a bone marrow biopsy tell you about RBCs, WBCs, and megakaryocytes?
number, size, and shape
Wheres the best place to do a bone marrow biopsy?
pelvis and possibly sternum and ribs because they are hemopoetically active