MS2 Podcasting Project Contact: Dr. Betsy Jones, 743-1100 x233 or betsy.jones@ttuhsc.edu 1

Texas Tech MedCast Podcast Episode Fact Sheet

Podcast Series Reynolds Geriatrics Series • USMLE Step1 Prep

Episode Title Long on Life, Short of Breath. Question 116 (2009 Sample Questions)

Personnel Left to Right: Katherine Duncan, Eddie Lowe, Fredrik Balldin, Rachel Mercer, Colbert Perez, Jackie Le, Steven Reeves, Alisa Thamwiwat, Grant Berry, Peter Wu, TTUSOM MS2

Recording Date April 9, 2009

USMLE Question Number: 116 Pg #: 46

A 75 year-old woman has increasing shortness of breath on exertion. Findings on physical examination are unremarkable. X-rays of the chest show no abnormalities of the heart or lungs. Pertinent laboratory findings include: hematocrit 28%, hemoglobin 9 g/dL, and mean corpuscular volume 70 µm3. Which of the following is the most likely basis for these findings? (A) Acquired hemolytic anemia (B) Chronic blood loss (C) Folic acid deficiency (D) Beta -thalassemia minor (E) Pernicious anemia

Learning Objectives The listener should be able to:

1) Determine a differential diagnosis based on the case presentation of a 75 year-old woman presenting with shortness of breath on exertion.

2) Discuss each of the answer choices (or diagnoses) and their manifestations: acquired hemolytic anemia, chronic blood loss, folic acid deficiency, Beta-thalassemia minor, pernicious anemia.

3) Decide which diagnosis is most likely and why.

MS2 Podcasting Project Contact: Dr. Betsy Jones, 743-1100 x233 or betsy.jones@ttuhsc.edu 2

Key Teaching Points

• Patients with beta-thalassemia minor have a defective gene that codes for the beta chain on hemoglobin. They are usually aysmptomatic with microcytosis on blood work.

• Acquired hemolytic anemias are split into two types, intrinsic types involving defects of the red blood cell itself, and extrinsic types involving defects outside of the red blood cell.

• Folic acid is found in green leafy vegetables and it is the most common vitamin deficiency in the US. A person lacking enough folic acid may have macrocytic megaloblastic anemia.

• Chronic blood loss could cause anemia if the patient does not have a sufficient bone marrow regenerative response. Chronic blood loss is one of the most common causes of iron deficiency in the western hemisphere.

• Pernicious anemia occurs when patients lack vitamin B12 due to an absorption defect. It can happen from a deficiency of intrinsic factor usually from loss of gastric parietal cells.

USMLE Test source:

http://download.usmle.org/2009step1.pdf

References 1. Goljan E: Rapid Review Pathology. Philadelphia, PA: Mosby, 2007; 208-212, 197, 202-203, 204-205. 2. Le T, Bhushan V: First Aid for the USMLE Step 1: 2009. New York: McGraw-Hill Medical, 2009; 96, 332, 334. 3. Vinay K, Abbas AL, Fauston N: Robbins and Cotran Pathologic Basis of Disease. New York: Saunders, 2004; 623-625, 624, 632-635, 638-642, 645-646. 4. http://www.anemia.org/patients/faq/.