Questions to ask when platelets are requested

1. Life-threatening bleed?
   • If so, release platelets
   • If not, consider next two questions
2. What is the cause?
   • increased destruction
   • decreased production
   • Will platelets help, harm, or do nothing?
3. Was treatment effective?
   • expected increase = 5-8 K/mcl/unit (40-60 K/mcl/pack)
   • If refractory, check for underlying cause and treat (see below)

Contraindications to transfusion

• Heparin-induced thrombocytopenia
• TTP/HUS

Causes of refractory thrombocytopenia

• Immune
  • ITP
  • HLA (Transfusion/pregnancy hx?)
• Nonimmune
  • Sepsis
  • Fever
  • DIC
  • Splenomegaly
  • Amphotericin B
  • Bone marrow transplant