Ambulatory Report Pearls – Retics, Anemia, Iron – 7.6.16

Thanks to Carine Davila for presenting an awesome case of a 57 yo F with a h/o premature ovarian failure @ age 17yo presenting with fatigue and dizziness and ultimately found to have hemodynamically stable significant microcytic anemia.
  • Pearls (many a la Brad Lewis, formerly at ZSFG)
    • Most cost effective initial workup of anemia is Ferritin, Reticulocyte Count, Smear
      • Ferritin  – sensitive/specific, EXCEPT in inflammation, liver dz, malignancy
    • Use the MCV!  (in the typical CBC skeleton, forget about the hematocrit, we’re not surgeons!  instead put the MCV under the hemoglobin)
    • If Ferritin is high and Transferrin low = Anemia chronic anemia
    • Transferrin < 10% —> give a trial of Iron
      • Consider IV Iron! (Iron Sucrose has a 0.002% risk of anaphylaxis vs. Iron Dextran which is 0.6-2.3%)
  • Reticulocytes, what’s the deal?
    • I love the Absolute Retic Count (I do NOT use the Reticulocyte Production Index, RPI)
    • Remember the 40-400-4-14 Curve
      • The line represents a Normal/Expected response in Absolute Retic Count based on varying Hemoglobins
        • if you’re Hgb is pretty normal at 14, then you shouldn’t have much of a reticulocyte count; conversely if your Hgb is low at 9, you should be mounting an absolute reticulocyte count in the 220s
      • Anything below the line represents an inappropriately low reticulocyte count —> then you gotta figure out why (see below “Sha Anemia Approach”)
      • How to make the Chart on ANY SURFACE
        • Y axis = Absolute Retic Count (Draw 40 and 400)
        • X axis = Hemoglobin (Draw 4 and 14)
        • Then Connect the Dots, and TEACH AWAY!
    • Expected Absolute Retic Count for Varying Hemoglobins.jpg
    • Hemoglobin and Absolute Retic Count Chart
  • Microcytic Anemia = TAILS
  • General Approach to Anemia
    • Sha Anemia Approach
    • I drew this a couple years ago, so sorry for the handwriting
    • Ignore the Retic Production Index, and just think about it in the following way: at the decision point in the Approach when you’re supposed to “Check Retic Production Index”:
      • “<2%” means that you have an Inappropriately Low Absolute Reticulocyte Index (ie. under the line in the 40-400-4-14 graph) and are Underproducing Hemoglobin
      • “>2%” means you are closer to the line in the 40-400-4-14 graph and you likely are having Increased Destruction
        • said another way, you have the tools/supplies to make the hemoglobin, they are just being eliminated/destroyed quickly

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