Thrombocytopenia

Background

• Spontaneous bleeding concerning when plt count <10-20K

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, 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. Transfusion Indications:
   1. <50K & severe bleed or invasive procedure
   2. <20K & fever, petechia, or infection
   3. <10K
2. Transufsion contraindications:
   1. TTP, DIC

1. 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

Pediatrics

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

Source

Tintinalli