RBC Disorders Flashcards
What is anemia?
Reduction in red cell mass
What clinical measurements help reflect (but do not directly measure) RBC mass?
- Red cell count
- Hemoglobin concentration
- Hematocrit
What is polycythemia?
An increase in RBC mass
What are the three major mechanisms of anemia?
- RBC loss = hemorrhage
- Decreased RBC survival = hemolysis
- Decreased RBC production = nutritional, aplastic anemia, myelophthistic anemias
Young, healthy individuals can tolerate up to _______ mL of rapid blood loss with minimal symptoms.
1000
What defines chronic hemorrhage?
Rate of RBC loss exceeds rate of RBC regeneration
Or iron reserves are depleted
What characterizes a hemolytic anemia?
Shortened RBC survival and retention of iron
What are the two major mechanisms for intravascular hemolysis?
- Immune: transfusion reaction
2. Non-immune: mechanical trauma (defective heart valve)
How does haptoglobin play a role in intravascular hemolysis?
When RBC is destroyed it releases Hemoglobin. Free hemoglobin is bound to haptoglobin and taken to liver to be cleared.
*Low haptoglobin levels key characteristic of intravascular hemolysis
Where are the typical sites of RBC destruction in extravascular hemolysis?
Spleen and liver
Which type of hemolysis will excrete excess hemoglobin and iron in the urine?
Intravascular hemolysis
Which type of hemolysis has the highest likelihood of jaundice due to hemoglobin breakdown products (bilirubin)?
Extravascular hemolysis
What type of hemolysis is caused by hereditary spherocytosis?
Extravascular
What protein is abnormal in a patient with hereditary spherocytosis?
Spectrin
What is the best treatment option for a patient with hereditary spherocytosis?
Splenectomy
Will stop destruction of RBCs, but will not change their malformation
