A 65-year-old woman comes to the office with a 2-month history of fatigue and dyspnea on exertion. She takes no medications. Her temperature is 36.7 C (98 F), blood pressure is 162/83 mm Hg, pulse is 100/min, and respirations are 21/min. Auscultation shows a 2/6 mid-systolic murmur in the second right intercostal space with normal S2 splitting. No peripheral edema is noted. Rectal examination shows guaiac-negative brown stool. ECG shows sinus tachycardia and nonspecific ST-T changes. Subsequent laboratory results are as follows: Which of the following is the most appropriate next step in management of this patient?

Question

A 65-year-old woman comes to the office with a 2-month history of fatigue and dyspnea on exertion.  She takes no medications.  Her temperature is 36.7 C (98 F), blood pressure is 162/83 mm Hg, pulse is 100/min, and respirations are 21/min.  Auscultation shows a 2/6 mid-systolic murmur in the second right intercostal space with normal S2 splitting.  No peripheral edema is noted.  Rectal examination shows guaiac-negative brown stool.  ECG shows sinus tachycardia and nonspecific ST-T changes.  Subsequent laboratory results are as follows:  Which of the following is the most appropriate next step in management of this patient?

Quizplus · Accepted Answer

This patient's laboratory values are consistent with a microcytic anemia from iron deficiency (low serum iron and ferritin with an elevated total iron-binding capacity). The evaluation of iron deficiency anemia (IDA) varies according to age group and patient-specific factors such as family history of colon cancer or presence of associated symptoms (eg, diarrhea in celiac disease). This patient has only nonspecific symptoms of anemia (dyspnea and tachycardia from hypoxemia, and a systolic murmur due to hyperdynamic circulation). New IDA in elderly patients should be considered to be from gastrointestinal (GI) blood loss (eg, polyps, cancer, angiodysplasia) until proven otherwise. In the clinical setting fecal occult blood tests (FOBTs) are frequently performed in patients before a diagnosis of iron deficiency is established with laboratory testing. When positive, FOBTs may guide the decision to perform colonoscopy and endoscopy in elderly patients, regardless of iron levels. However, a single negative FOBT is not sufficient to exclude occult GI bleeding. Elderly patients with IDA should be evaluated with colonoscopy and endoscopy despite a single negative FOBT, especially if no other obvious source of chronic blood loss is identified. (Choice A) Bone marrow biopsy is usually not required in the workup of IDA. Appropriate workup includes a search for the cause of iron deficiency (eg, chronic blood loss, malabsorption, poor dietary intake). Patients with IDA can develop a reactive thrombocytosis. (Choice C) Aortic stenosis may also present with a systolic murmur. When severe, it is associated with GI angiodysplasia causing occult GI bleed. However, normal S2 splitting essentially excludes severe aortic stenosis. (Choice D) Endomysial and tissue transglutaminase IgA antibodies are found in celiac disease. Patients usually present at a younger age (typically <40) and have associated symptoms such as chronic or intermittent diarrhea, foul-smelling stools, and flatulence. (Choice E) Radioisotope scans are useful in determining the source of active bleeding but are not diagnostic in the absence of an active bleed. They are typically used in acute (not chronic) GI blood loss when the source of bleeding remains unidentified on colonoscopy and endoscopy. Educational objective: The most common cause of iron deficiency anemia in the elderly is gastrointestinal blood loss. The next step in evaluation would be colonoscopy and endoscopy. A single negative occult blood test does not exclude the possibility of gastrointestinal bleeding. References: Iron status and colorectal cancer in symptomatic elderly patients. (http://www.ncbi.nlm.nih.gov/pubmed/19028203) Iron deficiency anemia in the elderly: prevalence and endoscopic evaluation of the gastrointestinal tract in outpatients. (http://www.ncbi.nlm.nih.gov/pubmed/12975553)

A 65-Year-Old Woman Comes to the Office with a 2-Month