Wednesday Morning Conference: Anemia

Source:  Wednesday Morning Conference: Anemia    Tag:  sideroblastic anemia

Anemia


We tackled the topic of ANEMIA this morning with Teekie.  Here is the summary!!

References:
Richardson, Microcytic Anemia, Pediatrics in Review 2007  http://pedsinreview.aappublications.org/content/28/1/5.full

Baker. Clinical Report Diagnosis and Prevention of Iron Deficiency and Iron-Deficiency Anemia in Infants and Young Children (0-3 years of age).
http://pediatrics.aappublications.org/content/126/5/1040.short?related-urls=yes&legid=pediatrics;126/5/1040


Physiologic Anemia of the newborn

  • Hb 17-20 at birth -> 9.5-11 at 2-3 months in term infant
  • Nadir for premie: 6.5-11
  • Due to no erythropoietin; not related to iron deficiency
  • Retic count 2-5% at birth -> <1% by 1 wk

Anemia:

  • 6 months- 6 years : H/H <11/33
  • 6-12 years: Hb <11.5
  • 12-19 years (girls): <12/36
  • 12-19 years (boys): <14/42
** 12% of 12 month-olds are iron deficient

MCV rule:

  • 1 year- 71, 2 years- 72, 3 years- 73.... >6 years: >76, 12-19 years: >80
  • Macrocytic: MCV >85

6 causes of hypochromic, microcytic anemia:

  • Iron deficiency
  • Thalessemia minor
  • Lead poisoning
  • Hemoglobin E trait
  • Chronic infection (often normocytic/normochromic)
  • Sideroblastic anemia- rare

Age for iron deficiency (2 growth periods in pediatrics):

  • Age 1-3 years
  • Adolescence (especially menstruating female)
  • >3 through adolescence with new anemia: think about bleeding
Perfect history for iron deficiency in a toddler:
  • Usually asymptomatic
  • "Hooked on milk": Should have <16 oz per day
  • Prolonged breastfeeding without supplementation at 6 months
  • Diet low in iron-rich foods

Labs c/w iron deficiency:

  • Hb <11
  • MCV low
  • RBC count low 3.5-5.5
  • Mentzer's MCV/RBC:  >13
  • Retic count <1%
  • Iron level <1
  • % Saturation <16%
  • TIBC high >300
  • Serum ferritin low <10 (falsely high if acute infection so get CRP)
  • CHr low 
  • ** Per Baker, best to get CHr or ferritin and CRP
Treatment
  • Elemental iron 3-6 mg/kg/day
    • Take with vitamin C or an empty stomach
    • S/E: Block stools, nausea, epigastric pain
  • Poly-vi-sol with iron = 10 mg iron
  • **Trial of iron is the ultimate confirmation
  • RTC in 1 mo -> expect increase in Hb by 1 gm --> then 2 more months of treatment to restore iron levels
    • Retic ct increases after 72 hours/doubles after 2 wks
    • If no 1 gm increase -> do more tests to determine the diagnosis you missed
Prevention in premies and other infants:
  • Lack of 3rd trimester iron transfer (unless multiple transfusions)
  • If breastfed, need 2 mg/kg/day elemental iron between 1-12 months by Fe drops or iron rich foods (continue PVS with iron until switched to formula and/or solids)
  • Formula-fed infants get iron from regular or preterm formula 
  • If VLBW: 4 mg/kg/day elemental iron between 1-12 mos
  • Term BF infants: have enough iron stores until 4-6 mos (then start extra iron 1 mg/kg/day in the form of fortified cereal 1 oz BID or supplement)
Iron deficiency anemia is also associated with:
  • Pica
  • Breath-holding spells
  • Strokes
When should you screen for iron deficiency anemia?
  • One-year-old
  • Two-year-old
  • Once for adolescent males
  • Periodically for menstruating adolescent females
  • 4 months for preemie
  • At-risk assessment at all other WCC
Kinds of hemoglobins:
  • Fetal Hb: 2 alpha + 2 gamma chains
    • At birth 70% of total Hb is F
    • Rapid decrease postnatally- adult level 2% by 6-12 months
  • HbA: 2 alpha + 2 beta chains
    • At birth is 30% of total Hb, 90% by 9-12 months
  • Hb A2: 2 alpha 2 delta chains
    • At birth <1% --> 2-3.4% by 6-12 months

Beta Thalessemia: 
  • Elevated A2 (alpha delta)
  • B-thal trait is #1 on differential with iron deficiency (6% Mediterranean population, 0.8% African American)
  • Beta-thal major: Two B0 genes--> No Hb A --> Severe anemia presenting >6 months of age
  • Thal intermedia: 2 mutated genes: 2 mild B+ genes or B+B0 genes (more serious)
  • Beta thal trait: Only one mutated gene
  • Mentzer's <13

Alpha Thalessemia:
  • Normal electrophoresis 
  • Missing 1 gene: silent carrier
  • Missing 2 genes: alpha trait (normal electophoresis)
  • Missing 3 genes: HbH disease
  • Missing 4 genes: Barts (fetal) hydrops
  • FA Barts--> Repeat electrophoresis at 6 months: If Hb Barts >25% it is HbH disease (otherwise, likely alpha trait)

Hemoglobin E:
  • B-chain variant- decreased amounts of B chain akin to B-thal
  • Trait: No or mild anemia with microcytosis
  • Elevated RBC's, Mentzer's <13
  • HbEE disease: Mild anemia, microcytosis
  • HbE-beta0 thal -> worse

NMS Quiz:
  • FA: wnl
  • FAS: Sickle trait
  • FS: Sickle disease or sickle beta0 thal or sickle persistence of fetal hemoglobin
  • FSC: SC disease
  • FSA: Sickle Beta+ thal
  • FASBarts: Sickle trait with alpha thal trait
  • F: Beta thal major
** Be aware of statistical anemia: With bell curve, 2.5% of normals with have Hb <11 (will have normal MCV, etc)