Thrombocytopenia

Background

• Spontaneous bleeding concerning when platelet count <20K

Clinical Features

• Nonpalpable petechiae/purpura
• Mucosal bleeding (gingival, epistaxis)
• Menorrhagia, hemoptysis, hematuria, hematochezia
• Deep tissue/joint bleeding is less common (more likely due to coagulopathies)

Differential Diagnosis

Coagulopathy

Platelet Related

• Too few
  • Thrombocytopenia
• Nonfunctional
  • Aspirin
  • Von Willebrand disease

Factor Related

• Acquired (Drug Related)
  • Warfarin (Coumadin)
  • Unfractionated heparin
  • Low molecular weight heparin (i.e. enoxaparin (Lovenox), dalteparin)
  • Factor Xa Inhibitors (e.g. rivaroxaban, apixaban, fondaparinux, edoxaban)
  • Direct thrombin inhibitors (e.g. dabigatran, argatroban, bivalirudin)
• Illness induced
  • Vitamin K deficiency
  • Disseminated Intravascular Coagulation (DIC)
  • Liver disease induced coagulopathy
  • Uremic bleeding syndrome
• Genetic
  • Hemophilia
  • Factor VIII inhibitor
  • Lupus anticoagulant

Diagnosis

• Platelet count (CBC)

Treatment

Platelet Transfusion Thresholds

most if not all of the following thresholds are based on weak recommendations with low quality evidence

• <50K if planned lumbar puncture or neurosurgical procedure
• <20K if planned for central venous catheter placement (preference toward compressible site), or febrile patient
• <10K in asymptomatic patients (unless due to ITP, TTP, or HIT)

There are no firm recommendations for transfusion thresholds in acute traumatic bleeding but many providers will opt for a goal of 100K, especially if there is evidence of ICH

Transfusion contraindications

• TTP, DIC, HIT

Pediatrics

• 1 unit of platelets per 5kg body weight raises count by 50k

See Also

• Coagulopathy (Main)
• Platelet Transfusion