104.2 📚 國考版醫垫國考 / PGY OSCE

104.2.0.1 📌 Cram Sheet

104.2.0.1.1 🔥 高 yield 10
  1. MCV > 100 + macroovalocytes + hypersegmented neutrophils (≥ 5 lobes)
  2. B12 def: anemia + subacute combined degeneration (dorsal + lateral)
  3. Folate def: anemia + glossitis + NO neuro
  4. MMA ↑ specific for B12; homocysteine ↑ both
  5. Pernicious anemia = autoimmune anti-IF + atrophic gastritis + 老人 + gastric CA risk
  6. B12 absorption: R-protein (stomach) → cleaved (pancreas) → IF binding → ileum
  7. B12 IM 1000 ÎŒg daily × 1 wk → weekly × 4 → monthly lifelong; OR oral 1000-2000 ÎŒg/d
  8. B12 first, then folate (avoid neuro worsening)
  9. Folate pregnancy 0.4 mg/d; antiepileptic + pregnancy planning 4-5 mg
  10. MTX rescue: leucovorin (folinic acid)
104.2.0.1.2 🔢 必背
項目 æ•žå­—
MCV macro > 100
Hypersegmented neutrophils ≥ 5 lobes
B12 def < 200 pg/mL definite; 200-300 borderline
MMA ↑ specific for B12
Homocysteine ↑ both B12 + folate
B12 IM dose 1000 ÎŒg
Oral B12 1000-2000 ÎŒg/d
Folate pregnancy 0.4 mg/d
Folate AED + pregnancy 4-5 mg/d
B12 stores 5-10 yr
Folate stores 3-4 mo

104.2.0.2 ⭐ 高 yield

104.2.0.2.1 Macrocytic Causes (Not Always Megaloblastic)
Megaloblastic (DNA defect) Non-megaloblastic
B12 def Alcohol
Folate def Liver disease
Drug: MTX, hydroxyurea, AZT, sulfasalazine, phenytoin, TMP Hypothyroid
Reticulocytosis
MDS (some)
COPD chronic
104.2.0.2.2 Pernicious Anemia Associations
  • APS-2 (Schmidt): + Hashimoto + T1DM
  • Atrophic gastritis (autoimmune)
  • Vitiligo
  • Gastric carcinoid + adenocarcinoma (3-5x risk)
  • Endoscopic surveillance considered
104.2.0.2.3 Drug Causing B12 / Folate Issue
  • B12: PPI, H2 blocker, metformin (chronic)
  • Folate: MTX, TMP, phenytoin, sulfasalazine, pyrimethamine
104.2.0.2.4 Differential Macrocytosis Without Anemia
  • Alcohol (most common)
  • Hypothyroid
  • Pregnancy
  • Drug (HU, AZT, MTX)
  • MDS early
  • B12/folate def early

104.2.0.3 🎯 自我檢枬

  1. MCV macro? → > 100
  2. Hypersegmented neutrophils lobes? → ≥ 5
  3. MMA specific for? → B12 def
  4. B12 def neuro? → Subacute combined degeneration
  5. Folate def neuro? → None
  6. Pernicious anemia Ab? → Anti-IF + anti-parietal
  7. B12 absorption site? → Terminal ileum + IF
  8. Pernicious anemia gastric risk? → CA + carcinoid (3-5x)
  9. B12 IM regimen? → 1000 ÎŒg daily × 1 wk → weekly → monthly lifelong
  10. Oral B12 effective? → Yes (1000-2000 ÎŒg/d, 1% passive absorption)
  11. B12 vs folate first? → B12 first (avoid neuro worsening)
  12. Folate pregnancy? → 0.4 mg/d
  13. AED + pregnancy folate? → 4-5 mg/d
  14. MTX rescue? → Leucovorin (folinic acid)
  15. Drug B12 def? → PPI, metformin, H2 blocker

⚠ AI 草皿。