Lecture 11: RBC Disorders Flashcards
Why do pregnant women develop physiologic anemia?
- RBC mass ↑; but plasma volume ↑ to a greater extent
- Therefore pregnant women develop lower hematocrit and hemoglobin levels
The WHO defines anemia as a hemoglobin of which level in men vs. women?
- Men = <13 g/dL
- Women = <12 g/dL
A peripheral blood smear finding of acanthocytes (red cells w/ a small number of spicules of variable size and distribution on the cell surface) is associated with what condition?
Liver disease
A peripheral blood smear finding of bite cells is associated with what conditions?
Oxidative hemolysis, due to unstable hemoglobins or potent oxidants (with or without G6PD or pyruvate kinase deficiency)
A peripheral blood smear finding of Echinocytes (red cells with a small number of spicules of uniform size and distribution on cell surface) is associated with what condition?
End-stage kidney disease
Spherocytes are associated with what conditions?
Hereditary spherocytosis and warm autoimmune hemolytic anemia
How are high levels of serum creatinine related to production of EPO?
↑ serum creatinine signifies underproduction of EPO
Why is serum testosterone useful in evaluating RBC disorders?
Used to assess possible hypotestosteronism in men, which may cause anemia
Target cells are a characteristic finding on peripheral smear in which disorder?
Thalassemia
List 3 causes of microcytic anemia associated with low or normal reticulocyte counts
- Iron-deficiency anemia
- Thalassemia
- Sideroblastic anemia
Aplasia, marrow infiltration, renal disease, inflammation, and chronic disease are all causes of what type of anemia?
Normocytic anemia w/ low or normal reticulocyte counts
What seen on BM biopsy distinguishes aplastic anemia from myelodysplastic syndrome or acute leukemia?
Marrow HYPOcellularity w/ ↑ fatty deposits
What are the treatment options for aplastic anemia?
- Allogenic HSC transplantation in those <40 y/o, whom are healthy, and have a HLA-compatible sibling
- Those not eligible should receive immunosuppressive therapy w/ antithymocyte globuin and cyclosporine
Name 2 toxins and 2 drugs which are associated with decreased heme synthesis?
- Toxins = alcohol and lead
- Drugs = chloramphenicol and isoniazid
Serum levels of what are the most useful test in the diagnosis of iron deficiency?
Ferritin
Why does serum ferritin have less diagnostic value in patients with an infection or inflammatory disorder?
Because ferritin = acute phase reactant
A patient on hemodialysis with iron-deficiency anemia should recieve what type of iron replacement therapy?
Parenteral iron therapy
What is the first thing to be evaluated in a patient with macrocytic anemia?
Reticulocyte count to rule out stress erythropoiesis (i.e., from bleeding or hemolysis)
What is a by-product of oxidant hemolysis and how does this affect arterial pO2 values?
Methemoglobin; pt’s with methemoglobinemia have higher than expected arterial pO2 values
How is the anemia of sickle cell disease classified and what is the reticulocyte count like?
Normochromic normocytic w/ ↑↑↑ reticulocyte count
What is the most common abnormality on echocardiography seen in older pt’s with sickle cell disease?
Pulmonary HTN showing up as signs of RV hypertrophy or strain
Which drug is indicated for use in sickle cell disease patients with albuminuria, even in the absence of HTN?
ACE inhibitors
When should a patient with sickle cell disease experiencing acute painful episodes (crises) be hospitalized?
- When the episodes do not resolve at home w/ oral analgesics after 1-2 days
or
- Do not resolve or improve significantly after a mininum of 4-6 hours of tx w/ parenteral opioids
At what O2 saturation or arterial PO2 should supplemental oxygen be used in pt with sickle cell disease?
O2 saturation <92% or arterial PO2 ≤70 mm
