Hematology Flashcards
What is the most common anemia?
Iron deficiency anemia
How do you know whether someone has anemia?
A reduction in one or more RBC measurements:
- Hemoglobin
- Hematocrit
- RBC count
What is the most common reason why people become anemic?
Blood loss
*Melena, hematemesis, trauma
What are other common reasons why people become anemic
- Sick bone marrow not making enough RBCs
2. RBCs are being destroyed at a rapid rate
Before making a diagnosis of anemia, always ask what question?
Who is my patient? Never presume that anemia in an older patient is due to aging. Although, up to 20% of older patients can have “idiopathic anemia of aging.”
What patients often have lower H&H?
Elderly
What patients often have a higher H&H?
People who live in higher altitudes (Ex. Denver).
*Rationale: oxygen is thin in higher altitudes and body compensates by making extra RBCs. Hematocrit will also be increased. Called polycythemia.
What patients are at risk of polycythemia (excess RBC)?
COPD & smokers because their tissues are chronically deprived of oxygen. When this occurs, as a compensatory mechanism, the body starts to pump out red bed cells resulting in increased numbers of Hgb & Hct.
Testosterone use can also result in polycythemia.
Every anemia is characterized by:
RBC size
RBC color
The suffix referring to cells:
Cytic
Define mico cytic?
Small cells
Define Normo cytic?
Normal-sized cells
Define Macro cytic?
Large cells
What makes a RBC red?
Hemoglobin
Define chromic suffix?
Color
Hypo chromic?
low in color (hgb)
Normo chromic?
normal color (hgb)
Hyper chromic?
too much color (hgb)
On a CBC, what describes the size of a patient’s RBC?
MCV (Mean Corpuscular Volume)
On a CBC, what describes the hemoglobin content of a patient’s RBCs?
MCH (Mean Corpuscular Hemoglobin)
In order to diagnose an anemia, what laboratory test are important to look at ?
MCV & MCH
What is RDW on a CBC?
Red Cell distribution width– variation of size of RBCs is ok but needs to be less than 15%.
Expectation that every red blood cell size should be within 15% of the next one. If the size varies by more than 15%, something is not right.
Remember story about donuts
What is a serum iron level?
How much iron is in circulation in the body.
What is a serum ferritin level?
How much iron is in storage.
Ferritin is a protein that stores iron
What is a reticulocyte count? What are reticulocytes? Where do they come from?
Reticulocyte is an immature RBC. Bone marrow spits out immature RBCs called reticulocytes. It takes about 24 hours for a reticulocyte to go from immature to mature
Why should reticulocytes be counted?
Reveals bone marrows ability to make RBCs when needed.
What lab test could be ordered to help determine whether a patient was taking an iron supplement daily for anemia?
Serum iron
*Rationale – when iron is taken by mouth, serum iron increases. If a patient is taking an iron supplement, the iron level should be high.
What question to always ask before ordering a serum iron level?
Are you taking an iron supplement or a multivitamin with iron.
*Rationale: If patient is taking iron, the serum iron levels will be increased, thus possibly causing a misdiagnosis of anemia.
What is a peripheral (blood) smear?
Drop of blood put on a slide and looked at under a microscope – measure the diameter of RBCs.
What is TIBC?
Total Iron Binding Capacity
Iron count is high = TIBC is low
Iron count is low = TIBC is high
*Iron binds to red blood cells; Iron does not like to swim around in bloodstream and always looking for somewhere to bind too. In an adult who is not deficient in iron, all of their iron binding sites will be full of iron. In an adult with iron deficiency anemia, there are plenty of sites where there is no iron sitting.
- **If there is plenty of iron, the capacity to sit iron is low, because all of the iron binding sites are full.
- **If deficient in iron, the capacity to sit iron is high because there is plenty of places where iron can come and bind.
***Ex. to help remember –> If an egg carton has 12 eggs in it, it’s full of eggs and the capacity to put another egg in it is low. Another carton has no eggs in it so the capacity to put eggs in is high. “Reciprocal relationship”
What is the most common anemia?
Iron deficiency anemia
What kind of anemia is iron deficiency anemia?
Microcytic anemia – small red blood cells
Classified as a microcytic hypo chromic anemia = small, pale cells
What is the most common cause of iron deficiency anemia?
Blood loss
When does a patient become symptomatic when they have iron deficiency anemia?
Most patients are asymptomatic until their H&H drops to about 30 & 10.
What are the classic findings (symptoms) of iron deficiency anemia in a young or middle aged adult?
Dizziness, fatigue, weakness, headache, irritability, exercise tolerance