Thrombocytopenia

Definition

<150,000 platelets/µL

Transfusion Criteria

1. <50,000 & severe bleed or invasive procedure
2. <20,000 & fever, petechia, or infection
3. <5,000-10,000 --> always?
   1. Usually ineffective in ITP (give only in severe bleed; best after IVIg)
   2. DIC may worsen with platlet tranfusion
   3. Likely contraindicated in TTP

Causes

1. Decreased production
   1. marrow infiltration, aplastic anemia, drugs (ETOH), viral infect
2. Increased destruction
   1. ITP, TTP, HUS, DIC, drugs (heparin)
3. Increased loss
   1. hemorrhage, hemodialysis
4. Splenic sequestration
5. Pseudothrombocytopenia (clumped)

Pediatrics

1 unit platelets per 5kg body weight will raise count by 50k

Source

1/26/06 DONALDSON (addapted from Tintinalli's, Lampe, Charfan)