Anemia Flashcards
Define anemia
a decrease in the amount of circulating RBCs
What things are usually decreased with anemia (regardless of type)
Packed Cell Volume (PCV)/Hematocrit (HCT)
RBC count
Hemoglobin concentration
Note: PCV and HCT are essentially the same test
Define regenerative anemia
The ability of the bone marrow to recognize that a decreased number of RBCs is present, responding to that decrease via production and release of immature RBCs (reticulocytes- slightly larger & contains less Hb than mature RBCs) into circulation.
How is regenerative anemia identified
- decreased HCT (or PCV)
- decreased RBC count
- decreased Hb concentration
- increased reticulocyte count
- polychromasia
- hypochromasia
- macrocytosis
+/- RBC parasites
define polychromasia
presence of multicolored RBCS with some RBCs showing up bluish-grey in certain dye stain
What does polychromasia indicate about the RBC
that there are different amounts of Hb present in the RBCs
Name 2 blood parasites
Babesia
Hemobartonella
Define macrocytosis
larger than normal RBC size
remember, reticulocytes are larger than normal RBCs
Define hypochromasia and why the color change is present
lighter than normal RBC color due to containing less Hb and therefore less red pigment;
pale RBCs with wide central pallor; different from polychromatic which is a light blue colored immature RBC, with the blue color being caused by residual RNA that can be stained
What is a reticulocyte, and what does it look like as compared to a mature RBC?
- immature RBC
- has nucleus
- larger
- contains less Hb, so paler in color
What are the 2 umbrella causes of regenerative anemia?
hemorrhage (loss or RBCs)
Hemolysis (destruction of RBCs)
Causes of hemorrhage (4)
- obvious external injury
- injury to internal organs that leads to rupture
- internal bleeding (trauma or coagulation abnormality)
- parasites
Causes of hemolysis
Primary–> immune system targets RBCs as abnormal and removes them from circulation; IMHA can be idiopathic or it can be secondary to another condition that alters RBCs or immune system to attack RBCs
Secondary –> administration or exposure to certain drugs/toxins
Define non-regenerative anemia
The inability of the bone marrow to either recognize that anemia is present or to respond through the production of immature RBCs.
How is nonregenerative anemia identified
- lack of polychromasia
- presence of normocytosis & normochromasia,
- normal or decreased reticulocyte count
Define normocytosis
normal sized RBCs
define normochromasia
normal colored RBCs also meaning normal Hg concentrations
_________________________ anemia may look like non-regenerative anemia because __________________.
- early regenerative
- it takes time for the bone marrow to respond if it is able to respond
What two things are evaluated for both types of anemia?
CBC
reticulocyte count
Two umbrella causes for nonregenerative anemia
- primary bone marrow disease
- effects of another disease upon the bone marrow
causes of primary bone marrow disease (3)
- neoplasia
- myelofibrosis
- bone marrow aplasia/hypotplasia
What is myelofibrosis?
scar tissue formation within the bone marrow
What is bone marrow aplsaia/hypoplasia? What are 3 things that can cause it?
a situation where some underlying reason causes the bone marrow to not produce precursors or mature RBCs;
can be the result of…
- giving certain drugs (estrogen)
- certain infectious agents (FeLV, FIV)
- immune mediated destruction of the precursors within the bone marrow itself
What are examples of another disease acting on the bone marrow that causes nonregenerative anemia? (4)
- Anemia of chronic disease (ACD)
- Iron deficiency (IDA)
- Anemia associated with renal disease
- Anemia associated with endocrine disease (Cushing’s/Addison’s)
How is anemia of chronic disease associated with anemia?
longstanding inflammation/degenerative/neoplastic disease creates the presence of chronic disease that sequesters iron within certain cells in the bone marrow making it unavailable to RBC precursor cells, resulting in decreased RBC production
What is the role of the RBC?
to transport hemoglobin (a molecule that carries O2) throughout the body
How does anemia affect O2 carrying capacity? How does that impact the body?
decreased O2 carrying capacity –> tissue hypoxia –> tissue dysfunction
How does anemia affect blood viscosity? How does that affect the body?
Decreased blood viscosity –> decreased resistance to blood flow –>body notices tissue hypoxia –> body increases HR & cardiac output to get more O2 to tissues
–>offsets tissue hypoxia if chronic, but usually can’t if acute
List clinical signs & reasons of acute onset anemia
- Tachypnea –> generalized hypoxia prompts NS to increase RR to get more O2 into the blood
- Tachycardia –> cardiac compensation increases HR
- Heart murmur –> due to thinner blood being more likely to “swirl” and cause turbulence
- Weak pulses –> due to decreased viscosity of blood
- Lethargy/weakness –> due to muscle hypoxia and generalized hypoxia
- Pale/white MMC –> due to decrease in RBC mass resulting in decrease of Hb concentration
- Icterus if hemolysis is present
