Platelet count

Background

• Count of circulating platelets; essential for primary hemostasis

Normal Values

• Normal: 150,000-400,000/mcL
• Thrombocytopenia: <150,000/mcL
• Thrombocytosis: >400,000/mcL

Interpretation

• Pseudothrombocytopenia: EDTA-induced platelet clumping is the most common lab artifact; confirm with peripheral smear or citrate tube
• Mild thrombocytopenia (100,000-150,000): usually clinically insignificant
• Moderate thrombocytopenia (50,000-100,000): liver disease, DIC, ITP, medications, hypersplenism
• Severe thrombocytopenia (<50,000): increased bleeding risk; consider TTP/HUS, HIT, ITP, DIC, bone marrow failure
  • Spontaneous bleeding risk increases significantly <10,000-20,000
• Platelet transfusion thresholds: <10,000 (prophylactic), <50,000 (active bleeding or invasive procedure), <100,000 (neurosurgery)

See Also

• CBC
• Thrombocytopenia
• ITP
• TTP
• DIC
• Platelet transfusion