Disseminated Intravascular Coagulation - DIC

Disseminated intravascular coagulation (DIC) is a disorder characterized by dysregulation of coagulation resulting in bleeding and coagulation, which without intervention may progress to organ failure and death. Laboratory findings suggestive of DIC consist of a low platelet count, elevation of the D-dimer and fibrinogen concentrations, and prolongation of prothrombin time (PT) and activated partial thromboplastin time (aPTT).

Diagnosis

Indications for Testing

Severe disease including sepsis, obstetrical disease, malignancy, liver disease, AND bleeding or microthrombi

Criteria for Diagnosis

  • Score overt disseminated intravascular coagulation (DIC) based on the following system recommended by the International Society on Thrombosis and Hemostasis (ISTH) (Toh, 2007)
    • Scores range from 0 to 8; a value of ≥5 is compatible with overt DIC

       

      ISTH Overt DIC Scoring System

      Score

      0

      1

      2

      3

      Platelet count (k/µL)

      >100

      50-100

      <50

       

      D-dimer (µg FEU/mL)

      No increase

       

      Moderate increase

      Strong increase

      Fibrinogen (g/L)

      >1

      <1

       

       

      Prothrombin time (increase in seconds)

      <3

      3-6

      >6

       

      FEU, fibrinogen equivalent units
      Toh, ISTH, 2007

Laboratory Testing

  • D-dimer – increased in acute and chronic DIC (best single test)
    • Normal D-dimer essentially rules out DIC (excellent negative predictive value)
    • Low specificity – elevations occur in numerous conditions (eg, pregnancy, venous thromboembolism, malignancy)
  • CBC 
    • Low platelets due to consumption
    • Platelet count may be normal in early DIC
  • Clotting times
    • Prothrombin time (PT) – normal or prolonged
    • Activated partial thromboplastin time (aPTT) – normal or prolonged (may be normal in early or chronic DIC)
    • Thrombin time (TT) – may be prolonged
  • Coagulation factors
    • Fibrinogen
      • Decreased in DIC
      • May not be accurate in early disease because it is an acute phase reactant
  • Clotting times and coagulation factors may be inaccurate in the presence of interfering substances, including drugs administered for anticoagulation

Differential Diagnosis

Background

Epidemiology

  • Incidence – >18/100,000 person-years (Singh, 2013)
    • May occur in 30-50% of patients with sepsis

Risk Factors

  • Sepsis (bacterial, viral, fungal)
  • Trauma (polytrauma, fat embolism, burns)
  • Malignancy (solid tumors, acute leukemia)
  • Obstetric complications (abruptio placentae, placenta previa, amniotic fluid embolus)
  • Toxic reactions (eg, venomous snake bite)
  • Immunologic reactions (hemolytic transfusion reaction, transplant rejection)
  • Organ destruction (pancreatitishepatic failure)
  • Massive blood loss

Pathophysiology

  • Activation of coagulation pathways
    • Generation of thrombin and formation of fibrin in circulating blood
    • Consumption of coagulation factors and platelets
  • Activation of inflammatory pathways via cytokines
  • Suppression of physiologic anticoagulant pathways
  • Activation and/or impairment of fibrinolysis

Clinical Presentation

  • Generally occurs in the setting of a risk factor listed above
  • Hemorrhage – petechiae, purpura, epistaxis, mucous membrane bleeding
  • Thrombosis – may lead to organ failure
  • Chronic disseminated intravascular coagulation (DIC) – Trousseau syndrome
    • Occurs in cancer patients
    • Primary symptom is thrombosis

ARUP Lab Tests

Aid in diagnosing and following disseminated intravascular coagulation (DIC)

Presence of rheumatoid factor may lead to false-positive results

Test should not be used to rule out venous thromboembolism (VTE)

Screen for coagulation disorder; order concurrently with prothrombin time (PT), partial thromboplastin time (PTT), thrombin time (TT), and fibrinogen

Initial test for suspected bleeding disorder

Initial test for suspected bleeding disorder

Assist in diagnosing dysfibrinogenemia or abnormalities with fibrin polymerization

Screen samples for the presence of heparin or direct thrombin inhibitors

Determine if fibrinogen deficiency is a potential cause of bleeding

Related Tests

Not recommended; order D-dimer test instead

Initial screen for inhibitor in plasma

Initial screen for inhibitor in plasma

Assist in diagnosing dysfibrinogenemia

May be useful for the evaluation of rare disorders such as primary fibrinolysis

For evaluating coagulopathies (eg, disseminated intravascular coagulation), D-dimer is the preferred test

Determine the cause for a prolonged PT or PTT

Condition-specific testing is recommended if the cause for the prolonged clotting time is known

Medical Experts

Contributor

Lehman

Christopher M. Lehman, MD
Associate Professor of Clinical Pathology, University of Utah
Medical Director, University of Utah Health Hospital Clinical Laboratory, ARUP Laboratories
Contributor
Contributor

Smock

Kristi J. Smock, MD
Associate Professor of Clinical Pathology, University of Utah
Medical Director, Hemostasis/Thrombosis, ARUP Laboratories

References

Additional Resources
Resources from the ARUP Institute for Clinical and Experimental Pathology®