PANCE Blueprint Hematology (5%)

50 y/o with acute onset syncope and weakness

Patient will present as → a 30-year-old obese white female presents with fatigue and generalized weakness for several weeks. Physical exam reveals pale nail beds, spoon nails, mucosal pallor, and an atrophic tongue. Upon further questioning, the patient reveals a "craving for ice and inanimate objects." Laboratory data shows a microcytic, hypochromic appearance to the RBCs, an elevated TIBC, low serum iron of 16 µg/dl, and low plasma ferritin of 12 µg/dl.

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↓ MCV (microcytic), ↑ TIBC, ↓ Ferritin (low iron stores) ↓  MCH (hypochromic)

Iron deficiency is the most common cause of anemia and usually results from blood loss

• In men, the most frequent cause is chronic occult bleeding, usually from the GI tract.
• In premenopausal women, menstrual blood loss is a common cause
• Another possible cause of blood loss in men and women is chronic intravascular hemolysis
• Fatigue with exercise, palpitations, shortness of breath, weakness, headaches, and tinnitus
• Tachycardia, tachypnea on exertion, pallor, glossitis, angular cheilitis, pica, koilonychia, jaundice, and splenomegaly

RBCs tend to be microcytic and hypochromic, and iron stores are low as shown by low serum ferritin and low serum iron levels with high serum total iron binding capacity

"Lead poisoning is a common question on the PANCE/PANRE look for Basophilic stippling and remember treatment is with EDTA."

Other causes of ↓ MCV include lead poisoning (look for this in a patient with neurological symptoms), sideroblastic anemia, basophilic stippling, and thalassemia. Treatment is with EDTA.

CBC

• Reticulocyte count: low
• RDW: high

Iron Studies

• Decreased serum iron, ferritin, and transferrin saturation
• Increased TIBC
• Ferritin <15 ng/mL (diagnostic)

Check hemoglobin and Hematocrit

• Check at 12 and 18 mo, 12 y (females)
• Hgb/Hct <2× standard deviation of normal
• Hgb <13.5 g/dL or → Hct <39% (men)
• Hgb <12 g/dL or Hct <37% (women)

Peripheral smear: poikilocytes (pencil or cigar-shaped cells)

• Rarely bone marrow examination
• Hemoccult if indicated

Iron can be provided by various iron salts (eg, ferrous sulfate, gluconate, fumarate) or saccharated iron PO 30 min before meals (food or antacids may reduce absorption)

• A typical initial dose is 60 mg of elemental iron (eg, as 325 mg of ferrous sulfate) given once/day or bid
• Larger doses are largely unabsorbed but increase adverse effects especially
• Ascorbic acid either as a pill (500 mg) or as orange juice, when taken with iron, enhances iron absorption without increasing gastric distress
• The response to treatment is assessed by serial Hb measurements until normal RBC values are achieved
• Hgb rises little for 2 weeks but then rises 0.7 to 1 g/wk until near normal, at which time rate of increase tapers
• Anemia should be corrected within 2 mo
• Increasing reticulocyte count is an indication that iron is working
• A subnormal response suggests continued hemorrhage, underlying infection or cancer, insufficient iron intake, or, very rarely, malabsorption of oral iron