Lecture 11: RBC Disorders

Question 1

Why do pregnant women develop physiologic anemia?

Answer 1

• RBC mass ↑; but plasma volume ↑ to a greater extent
• Therefore pregnant women develop lower hematocrit and hemoglobin levels

Question 2

The WHO defines anemia as a hemoglobin of which level in men vs. women?

Answer 2

• Men = <13 g/dL
• Women = <12 g/dL

Question 3

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?

Answer 3

Liver disease

Question 4

A peripheral blood smear finding of bite cells is associated with what conditions?

Answer 4

Oxidative hemolysis, due to unstable hemoglobins or potent oxidants (with or without G6PD or pyruvate kinase deficiency)

Question 5

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?

Answer 5

End-stage kidney disease

Question 6

Spherocytes are associated with what conditions?

Answer 6

Hereditary spherocytosis and warm autoimmune hemolytic anemia

Question 7

How are high levels of serum creatinine related to production of EPO?

Answer 7

↑ serum creatinine signifies underproduction of EPO

Question 8

Why is serum testosterone useful in evaluating RBC disorders?

Answer 8

Used to assess possible hypotestosteronism in men, which may cause anemia

Question 9

Target cells are a characteristic finding on peripheral smear in which disorder?

Answer 9

Thalassemia

Question 10

List 3 causes of microcytic anemia associated with low or normal reticulocyte counts

Answer 10

• Iron-deficiency anemia
• Thalassemia
• Sideroblastic anemia

Question 11

Aplasia, marrow infiltration, renal disease, inflammation, and chronic disease are all causes of what type of anemia?

Answer 11

Normocytic anemia w/ low or normal reticulocyte counts

Question 12

What seen on BM biopsy distinguishes aplastic anemia from myelodysplastic syndrome or acute leukemia?

Answer 12

Marrow HYPOcellularity w/ ↑ fatty deposits

Question 13

What are the treatment options for aplastic anemia?

Answer 13

• 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

Question 14

Name 2 toxins and 2 drugs which are associated with decreased heme synthesis?

Answer 14

• Toxins = alcohol and lead
• Drugs = chloramphenicol and isoniazid

Question 15

Serum levels of what are the most useful test in the diagnosis of iron deficiency?

Answer 15

Ferritin

Question 16

Why does serum ferritin have less diagnostic value in patients with an infection or inflammatory disorder?

Answer 16

Because ferritin = acute phase reactant

Question 17

A patient on hemodialysis with iron-deficiency anemia should recieve what type of iron replacement therapy?

Answer 17

Parenteral iron therapy

Question 18

What is the first thing to be evaluated in a patient with macrocytic anemia?

Answer 18

Reticulocyte count to rule out stress erythropoiesis (i.e., from bleeding or hemolysis)

Question 19

What is a by-product of oxidant hemolysis and how does this affect arterial pO₂ values?

Answer 19

Methemoglobin; pt’s with methemoglobinemia have higher than expected arterial pO₂ values

Question 20

How is the anemia of sickle cell disease classified and what is the reticulocyte count like?

Answer 20

Normochromic normocytic w/ ↑↑↑ reticulocyte count

Question 21

What is the most common abnormality on echocardiography seen in older pt’s with sickle cell disease?

Answer 21

Pulmonary HTN showing up as signs of RV hypertrophy or strain

Question 22

Which drug is indicated for use in sickle cell disease patients with albuminuria, even in the absence of HTN?

Answer 22

ACE inhibitors

Question 23

When should a patient with sickle cell disease experiencing acute painful episodes (crises) be hospitalized?

Answer 23

• 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

Question 24

At what O₂ saturation or arterial PO₂ should supplemental oxygen be used in pt with sickle cell disease?

Answer 24

O₂ saturation <92% or arterial PO₂ ≤70 mm