Step Up - Hematologic Diseases and Neoplasms Flashcards
Anemia - Definition:
A reduction in Hct or Hb concentration.
When red cell mass decreases, several compensatory mechanisms maintain O2 delivery to the tissues. These include:
- UP CO.
- UP extraction ratio.
- Rightward shift of the oxyhemoglobin curve (Incr. 2,3-DPG).
- Expansion of plasma curve.
As a general rule, blood transfusion is NOT recommended UNLESS either of the following is true:
- Hb <7 OR
2. Patient requires incr. O2-carrying capacity - patients with CAD or some other cardiopulmonary disease.
Symptoms of anemia are highly variable, depending on:
- How rapidly the Ht drops.
- Underlying condition of the patient.
- Ht level the patient typically lives on.
Pseudoanemia:
Refers to a decrease in Hb and Ht 2o to dilution (ie 2o to acute volume infusion or overload).
If Ht and Hb reveals anemia, next tests to obtain to determine the cause of anemia are:
- Reticulocyte count
2. MCV
All anemias are initially?
Normocytic - it takes some time for the abnormal-sized RBCs to outnumber the normal-sized ones.
Anemia of liver disease:
MCV up to 115 - due to altered metabolism of plasma lipoproteins into their membranes, altering RBC shape (and incr. volume).
Normocytic anemia - DDX:
- Aplastic anemia
- Bone marrow fibrosis
- Tumor
- Anemia of chronic disease
- Renal failure
If the reticulocyte index is >2, do the following:
- Suspect blood loss –> Look for the source of bleeding.
2. Suspect hemolysis.
In an anemic patient, 1st step is:
To assess the volume status + hemodynamic stability.
If unstable, transfuse PRBCs BEFORE attempting to find the cause of anemia.
Dietary deficiency/incr. iron requirements - primarily seen in:
- Infants and toddlers.
- Adolescents.
- Pregnant women.
Microcytic anemias - Serum ferritin:
Fe def. –> Low.
Beta thal –> Normal/high.
ACD –> Normal/high.
Microcytic anemias - Serum Iron:
Fe def –> Low.
Beta thal –> Normal/high.
ACD –> Low.
Microcytic anemias - TIBC:
Fe def. –> High.
Beta thal –> Normal.
ACD –> Normal/low.
Microcytic anemias - RDW:
Fe def. –> High.
Beta thal –> Normal/high.
ACD –> Normal.
Treatment of iron def. anemia:
- Oral iron replacement (ferrous sulfate).
- Parenteral iron replacement (iron dextran IV, IM).
- Blood transfusion is NOT recommended unless anemia is severe or the patient has cardiopulmonary disease.
What is the main pathogenetic mechanism in beta thal?
Excess ALPHA-chains bind to and damage the RBC membrane.
Cooley’s anemia - another name?
Beta thal major.
Diagnosis of beta thal major:
- Hb electrophoresis –> HbF + HbA2 UP.
2. Peripheral smear –> Microcytic/hypochromic, TARGET cells may be seen.
Sideroblastic anemia - Clinical findings:
- Incr. serum iron + ferritin.
- Normal TIBC.
- TIBC sat is normal/elevated –> Distinguishes it from Fe def.
- Ringed sideroblasts in bone marrow.
Sideroblastic anemia - Treatment:
Remove offending agent - Consider pyridoxine.
Aplastic anemia - Can transform into a leukemia?
Yes - Into acute leukemia.
Aplastic anemia - Diagnosis:
- Normocytic/chromic anemia.
- Perform a bone marrow biopsy for definitive diagnosis - This reveals HYPOCELLULAR marrow and the absence of progenitors of all 3 hematopoietic cell lines.