Iron Deficiency Anemia: Evaluation and Management
MATTHEW W. SHORT, LTC, MC, USA, and JASON E. DOMAGALSKI, MAJ, MC, USA, Madigan Healthcare System, Tacoma, Washington
Am Fam Physician. 2013 Jan 15;87(2):98-104.
Iron deficiency anemia was my favorite anemia in medical school because it was the easiest one to remember, and was my go-to choice on long multiple choice exams. The lab results always had a microcytic anemia, low serum iron, low transferrin, and a HIGH TIBC. Unfortunately, patients don't come in with scantrons and #2 pencils, so I have to really understand this stuff.
Even though medical school taught me that I needed microcytic anemia in the diagnosis of iron deficiency, up to 40% of patients can present as normocytic. According to this article, we can keep iron deficiency in the differential for patients with an MCV up to 95um3. At this point we can look at the serum ferritin. Even though a level below 15ng/ml is considered iron deficient, it is more practical to use a cutoff of 30ng/ml to improve sensitivity. It the patient has chronic inflammation, we can bump the cutoff to 50ng/ml, because ferritin is an acute phase reactant. If the ferritin level is in the "fuzzy" area ( between 31-99ng/ml), then we have to do more lab tests, especially if the TIBC, serum iron, and transferrin are not congruent with iron deficiency.
At this point in the diagnosis, we can consider soluble transferrin receptor testing, which measures erythropoiesis. This will be increased in iron deficiency. If it is low, your patient may not have a problem with iron, but if it is normal, you need to check erythrocyte protoporphyrin levels. This should be increased in iron deficiency. If its not increased, it may be time for a bone marrow biopsy.
This article also discusses possible causes, treatment, and screening. Please check it out. The algorithms are great in it too!
No comments:
Post a Comment