Platelet Disorders

Thrombocytopenia (Plt count <150,000/µL)

Thrombocytopenia and Risk of Bleeding
Platelet Count (cells/µL) Risk
50,000–100,000 Risk with major trauma; can proceed with general surgery
20,000–50,000 Risk with minor trauma or surgery
<20,000 Risk of spontaneous bleeding (less so with ITP)
<10,000 Risk of severe, life-threatening bleeding

Etiologies

  • production
    • Hypocellular bone marrow: aplastic anemia (qv), rarely MDS, drugs (eg, thiazides, antibiotics, chemotherapy), alcohol, cirrhosis
    • Hypercellular bone marrow: MDS, leukemia, severe megaloblastic anemia
    • Marrow replacement: myelofibrosis, hematologic and solid malignancies, granulomas
  • destruction
    • Immune-mediated (distinguish primary from secondary; Blood 2009;113:2386) Primary (idiopathic): immune rombocytopenic purpura (