Thrombocytopenia

Background

• Spontaneous bleeding concerning when plt count <20K

Clinical Features

• Nonpalpable petechiae/purpura
• Mucosal bleeding (gingival, epistaxis)
• Menorrhagia, hemoptysis, hematuria, hematochezia
• Deep tissue bleeding is less common

Causes

1. Decreased production
   1. Marrow infiltration (tumor or infection)
   2. Viral infections (rubella, HIV)
   3. Drugs
      1. Heparin Induced Thrombocytopenia
      2. sulfa abx, ETOH, ASA, thiazides/furosemide
   4. Radiation
   5. Vitamin B12 and/or folate deficiency
2. Increased platelet destruction
   1. ITP
   2. TTP
   3. HUS
   4. DIC
   5. Viral infections (HIV, mumps, varicella, EBV)
   6. Drugs (heparin, protamine)
3. Platelet loss
   1. Excessive hemorrhage
   2. Hemodialysis, extracorporeal circulation
4. Splenic sequestration
   1. Sickle cell disease, cirrhosis

Treatment

1. Platelet Transfusion Indications:
   1. <50K & severe bleed or invasive procedure
   2. <20K & fever, petechia, or infection
   3. <10K
2. Transfusion contraindications:
   1. TTP, DIC, HIT
3. Peds
   1. 1u plt per 5kg body weight raises count by 50k

See Also

• Coagulopathy (Main)
• Platelet Transfusion

Source

Tintinalli