Superficial bleeding (petechiae, purpura, mucosal bleeding), epistaxis, menorrhagia


AutoimmuneITP, SLE, RA
ConsumptionHUS/TTP, DIC, HT
ProductionBone marrow failure (presents as pancytopenia), Myelodysplasia, B12/Folate deficiency
Drug inducedNSAIDs, sulfa drugs, IIb/Illa inhibitors, Heparin, Quinine, EtOH
InfectionHIV, Hep C, EBV
GeneticBernard Soulier (AR Defect in GPIb-IX), Glanzmann Thrombasthenia (AR Defect in GPIIb-Illa)
SequestrationSeen with hypersplenism, portal hypertension
PseudoPseudothrombocytopenia (platelet clumping, resulting in abnormal test)
Special ScenariosMalignancy (bone marrow invasion or DIC), Pregnancy (gestational thrombocytopenia, preeclampsia, HELLP), Liver failure (I TPO, splenic sequestration)
Uniat Superficial bleedingPetechiae, purpura, mucosal bleeding, epistaxis, menorrhagia


  • Exam for signs of bleeding
  • CBC in citrated blood tube, INR, PTT, fibrinogen, D-dimer, blood smear
  • Additional considerations: Heparin-PF4 antibody (if 4T-score is 4-8), ultrasonography for DVT evaluation, ferritin (if concern for HLH), liver function tests (if cirrhosis suspected), TEG in complex cases

Immediate concerns

  • Evaluate risk of bleeding: Review anticoagulant medications, consider discontinuation, and platelet transfusion if necessary
  • Consider HIT (Heparin-Induced Thrombocytopenia)
  • If schistocytes are present, consider TTP (Thrombotic Thrombocytopenic Purpura)


  • Want platelets > 50k prior to procedure
  • Platelet transfusion: Active bleeding with count < 50k OR any person < 10k

Heparin Induced Thrombocytopenia


  • HIT results from autoantibodies that react to a combination of heparin and platelet factor 4 (PF4), leading to platelet activation and thrombosis
  • Risk factors include female sex, older age, obesity, and hemodialysis
  • Consider HIT in patients recently treated with heparin who have new-onset thrombocytopenia, skin necrosis at injection sites, anaphylactoid response to heparin, or venous/arterial thrombosis

Risk Stratification and Diagnostic Tests for HIT

  • Use the 4T score for risk stratification
  • The heparin-PF4 antibody test has high sensitivity but poor specificity
  • Serotonin Release Assay (SRA) is the gold standard diagnostic test, but it is expensive and time-consuming

4Ts Score for Heparin-Induced Thrombocytopenia

Management and Treatment of HIT

  • Initiate empiric anticoagulation therapy for HIT in patients with clinical thrombosis on therapeutic heparin anticoagulation
  • Switch heparin to a non-heparin agent such as argatroban
  • For patients without clinical thrombosis but a high likelihood of HIT, empiric anticoagulation with a non-heparin agent should generally be started before confirmation of the diagnosis
  • Non-heparin anticoagulants
    • Argatroban is perhaps most commonly used (with a similar option being Bivalirudin)
    • Fondaparinux could be considered in intermediate-likelihood situations, at a reduced dose (2.5 mg sq daily)