ANEMIA Anemia: decrease in the number of RBCs, Hb content, or Hct content below the lower limit of the normal range for the age and sex of the individual Pediatric Anemia A. Hemolytic Anemia: there is premature destruction of RBCs 1. Hereditary Spherocytosis: most common inherited abnormality of RBC membrane; defect in ankyrin, band 3 or spectrin proteins surface area deficiency leading to spherocytosis 2. Pyruvate Kinase Deficiency: defect in PKLR gene PK cannot convert phosphoenolpyruvate to pyruvate low ATP levels producing membrane injury 3. G6PD Deficiency: defect in G6PD protein G6PD enzyme cannot oxidize glucose-6-phosphate to 6-phosphogluconate (which concomitantly reduces NADP+ to NADPH, which protects RBCs from oxidative stresses) no NADPH makes RBCs susceptible to oxidative stresses 4. Thalassemia: imbalance in alpha and beta globin chain production disruption of RBC maturation leading to ineffective erythropoiesis B. Normal Lab Values (important to determine if there is anemia)
*Remember: Normal values vary depending on the source and might cause confusion. So just try to memorize the magic numbers to simplify things.
Nutritional Anemias 1. Folic Acid Deficiency Anemia: macrocytic, megaloblastic anemia 2. Vitamin B12 Deficiency Anemia: macrocytic megaloblastic anemia 3. Iron Deficiency Anemia: microcytic, hypochromic anemia Serum Iron ↓ ↑/N ↑ ↓ Total Iron Binding Capacity ↑ (only IDA has high TIBC) ↓/N ↓/N ↓ % Saturation ↓ ↑/N ↑ ↓
Hct Hgb
M: 38.8-46.4 F: 35.4-44.4 M: 13.3-16.2 F: 12.0-15.8 4-5 6 3 x 10 /mm 2
MAGIC NUMBER: 35 (Equivalent measurements: Packed Cell Volume, Erythrocyte Volume Fraction) MAGIC NUMBER: 12 MAGIC NUMBER: 4,000,000/mm
3
IDA Thal SA ACD Time 12-24 H 36-48 H 48-72 H 4-30 D 1-3 M C.
RBC count RPI
Reticulocyte Production Index: to determine reticulocyte response to anemia [Retic Count x (Hct/Normal Hct)]/2 (hypoproliferative: 2)
MCH
27-31
Mean Cell Hemoglobin: Hgb/RBC