Sickle Cell

  • HY
  • do a lot of good as a physician knowing this

Hypoxia or Acidosis

a2b2 = Hgb A1

a on Ch 11

  • 4 copies
  • if absent = hydrops fetalis

b on Ch. 16

  • 2 copies
  • Glu→Val = HbSS
    • HbgSS, can sickle cells

a2y2 = HgbF

Sickling RBC

  • rigid, nondeformable

Can't fit thru capillaries: no distal bf (ischemia)

back pressure → hemolysis → cell breakdown products enter blood

💥 →UB released into blood →liver conjugation → stool 💩

  • always some jaundice at baseline
    • Bili 1-2 (↑ than nl)
  • pigmented gallstones → cholecystectomy
  • anemia
    • obtain CBC & bili for baseline

Anemia → poor O2 carrying cap. → EPO in kidneys

  • elevated baseline reticulocyte
    • want to know this

Tx:

  • folate
  • Fe
  • Deferoxamine
    • Fe overload from pRBC transfusions

Acute

  • Acute chest
    • Exchange transfusion
      • urgent
  • Priapism 🍆
    • drainage of penis before → exchange transfusion

Chronic:

  • auto infarct spleen
    • risk of encapsulated organisms
  • PPx penicillin ✏ until 5y
  • Pneumococcal Vaccine

bone ischemia

  • ↑OM
    • always S. Aureus
    • if Salmonella → SCD
  • Avascular Necrosis of Hip
    • can be any bone
    • but hip we care about
      * conservative management (crutches)
      • then Sx 🔪

Pt: Anemia, ↑reticulocytes, ↑bilirubin

  • chronic pain
  • CBC: sickled cells → Hb electrophoresis (once)
    • provides variant

Tx:

  1. Chronic issues
  2. Acute crisis
    • more cells sickle in crisis = more px, issues, ↑ joint pain
  3. Vasocclusive crisis
    • sickled cells, ↑reticulocytes/bili from baseline, ↓Hb
    • IVF
    • O2 (↓hypoxemia)
    • Pain control (no upward limit, give it all)
    • ± Abx if infection

f/u: psychosocial stressors

  • Hydroxyurea: HbF cant sickle

Variants

HbSC: not disease

  • ↓Hgb, but no Sx
  • 1 gene, trait
  • pregnancy counseling

HbSB thal (+)

  • mild form

HbSB thal 0

  • worst form