The Approach To The Anemic Patient Flashcards
Hemoglobin
Directly measures the concentration of hemoglobin
Hematocrit
Measurement of the volume of RBCs per total volume of blood. Given in percentage. It’s a calculated value in an automated CBC.
Hematocrit is about 3 times the hemoglobin.
What is the formula to calculate Hematocrit?
Hct = RBC x MCV
RBC count
Direct measurement of the number of red cells per volume of blood.
MCV (Mean Corpuscular Volume)
Direct measurement of red cell volume in femtoliters.
RDW (Red Cell Distribution Width)
Coefficient of variation of MCV. It measures how much spread there is in the MCVs of all of the different RBCs in the patient.
Define Anemia
A decreased hemoglobin/hematocrit below the normal range.
hypotension, orthostatic changes, syncope, shock are symptoms of Acute Hemorrhage that are related to
Hypovolemia (decrease in blood volume)
fatigue, dyspnea, fast heart rate (tachycardia), angina/claudication, cognitive difficulties are symptoms related to
tissue hypoxia
What are acute changes of body in response to anemia?
- increased cardiac output (tachycardia)
2. hypovolemia triggers vasoconstriction
What are chronic changes of body in response to anemia?
- Increase in blood volume due to kidneys retaining salt and water to expand intravacular volume.
- Increased 2,3-DPG
- Increased erythropoietin synthesis (hormone produced by kidneys to increase RBC production)
What are two ways to classify Anemia?
- By the erythropoietic response (through reticulocyte count)
- By the RBC size (through MCV) & hemoglobin concentration
Hyperproliferative vs. Hypo-proliferative
Hyperproliferative: plenty of reticulocytes
Hypoproliferative: not enough reticulocytes
Hypo-chromic vs Normochromic
Hypochromic means that the red blood cells have less hemoglobin than normal.
Normochromic means that the red blood cells have normal concentration of hemoglobin.
How does reticulocytes appear to differet stains?
- Wright-Giemsa Staining: Polychromatophilic (grayish blue)
2. Supravital Staining: RNA remnants (reticulated)
Reticulocyte Index
retic count x (actual Hct / ideal Hct) x 0.5
Absolute Reticulocyte Count
retic (%) x RBC
The retic index < 2% or absolute retic count < 75,000 indicates
a problem with bone marrow response. This is known as hypo-proliferative anemia.
The retic index > 2% or absolute retic count > 100,000 indicates
that the marrow response is normal but the cause of anemia is either blood loss or hemolysis. This is known as hyper-proliferative anemia.
Microcytic vs. Macrocytic vs. Normocytic
Microcytic: small RBC size (low MCV <80)
- associated with hemoglobin synthesis defect
Macrocytic: big RBC size (high MCV >100)
- megaloblastic (impaired DNA synthesis)
- non-megaloblastic (many reasons)
Normocytic: normal RBC size
- either marrow isn’t working well or mixed problems
T/F: There is NO ABSOLUTE hemoglobin value that should be a trigger in every patient
True
What are some situations that call for RBC transfusion?
- cardiovascular compromise (congestive heart failure, shock, angina)
- Hypoproliferative anemia with no recovery
- Anemic patient getting surgery with the potential for blood loss
