Disseminated Intravascular Coagulation (DIC)

Key Features

Essentials of Diagnosis

• Associated with cancer, infection, trauma, and obstetrical patients

• Prolonged prothrombin time (PT) and activated partial thromboplastin time (aPTT)

• Thrombocytopenia

• Low/declining fibrinogen levels

General Considerations

• Results from uncontrolled local or systemic activation of coagulation, which leads to depletion of coagulation factors and fibrinogen and often results in thrombocytopenia as platelets are activated and consumed

• Numerous disorders are associated with DIC

  • Sepsis (in which coagulation is activated by presence of lipopolysaccharide)

  • Cancer

  • Trauma

  • Burns

  • Pregnancy-associated complications (in which tissue factor is released)

• Aortic aneurysm and cavernous hemangiomas may promote localized intravascular coagulation

• Snake bites may result in DIC due to the introduction of exogenous toxins

• The HELLP syndrome (hemolysis, elevated liver enzymes, low platelets) is a severe form of DIC with a particularly high mortality rate that occurs in peripartum women

Clinical Findings

Symptoms and Signs

• Bleeding usually occurs at multiple sites, such as intravenous catheters or incisions, and may be widespread (purpura fulminans)

• Malignancy-related DIC may manifest principally as thrombosis (Trousseau syndrome)

Differential Diagnosis

• Severe liver disease

• Thrombotic thrombocytopenic purpura

• Sepsis-induced thrombocytopenia or anemia

• Heparin-induced thrombocytopenia

• Other microangiopathic hemolytic anemia (eg, prosthetic valve hemolysis)

Diagnosis

Laboratory Tests

• Thrombocytopenia

• In early DIC

  • Platelet count and serum fibrinogen levels often initially remain within the normal range

  • Progressive thrombocytopenia (rarely severe)

  • Prolongation of PT

  • Decrease in fibrinogen levels

  • Elevation in aPTT

  • D-dimer levels typically elevated

  • Schistocytes on the blood smear in 10–20% of patients

• In the HELLP syndrome

  • Elevated liver transaminases

  • Kidney injury due to gross hemoglobinuria and pigment nephropathy

• Malignancy-related DIC may feature normal platelet counts and coagulation studies but a dropping platelet count and fibrinogen, with a rising INR, are often seen

Treatment

Medications

• Underlying causative disorder must be treated (eg, antimicrobials, chemotherapy, surgery, or delivery of conceptus)

• If clinically significant bleeding is present, hemostasis must be achieved; following is a strategy of managing DIC:

  • Assess for underlying cause of DIC and treat

  • Establish baseline platelet count, PT, aPTT, D-dimer, fibrinogen

  • Transfuse blood products if ongoing bleeding or high risk of bleeding

    • Platelets: goal > 20,000/mcL (most patients) or > 50,000/mcL (severe bleeding, eg, intracranial hemorrhage)

    • Cryoprecipitate: goal fibrinogen level > 80–100 mg/dL

    • Fresh frozen plasma: goal PT and aPTT < 1.5 × normal

    • Packed red blood cells: goal hemoglobin > 8 g/dL or improvement in symptomatic anemia

  • Follow platelets, aPTT/PT, fibrinogen every 4–6 hours or as clinically indicated

  • Heparin (initial infusion, 5–10 units/kg/h)

    • May be considered when bleeding is persistent

    • Do not administer bolus

    • Contraindicated if platelets cannot be maintained at > 50,000/mcL, in cases of gastrointestinal or ...