What are the diagnostic criteria and treatment options for Disseminated Intravascular Coagulation (DIC)?

Diagnosis and Management of Disseminated Intravascular Coagulation (DIC)

The diagnosis of DIC requires a systematic approach using the International Society on Thrombosis and Haemostasis (ISTH) scoring systems, with treatment primarily focused on addressing the underlying cause while providing appropriate supportive care based on clinical presentation. 1

Diagnostic Criteria for DIC

ISTH Overt DIC Scoring System (Score ≥5 indicates overt DIC)

• Platelet count:

  • <50 × 10^9/L: 2 points
  • ≥50, <100 × 10^9/L: 1 point 1, 2

• Fibrin-related markers (D-dimer or FDP):

  • Strong increase: 3 points
  • Moderate increase: 2 points 1, 2

• Prothrombin time (PT):

  • ≥6 seconds above normal or PT ratio >1.4: 2 points
  • ≥3 seconds, <6 seconds above normal or PT ratio >1.2, ≤1.4: 1 point 1, 2

• Fibrinogen level:

  • <100 mg/dL: 1 point 1, 2

Sepsis-Induced Coagulopathy (SIC) Scoring System (Score ≥4 indicates SIC)

• Platelet count:

  • <100 × 10^9/L: 2 points
  • ≥100, <150 × 10^9/L: 1 point 1, 2

• Prothrombin time (PT ratio):

  • 1.4: 2 points

  • 1.2, ≤1.4: 1 point 1, 2

• SOFA score (Sequential Organ Failure Assessment):

  • ≥2: 2 points
  • 1: 1 point 1, 2

Laboratory Testing for DIC

Essential Laboratory Tests

• Complete blood count with platelet count (thrombocytopenia is common) 3
• Prothrombin time (PT) and partial thromboplastin time (PTT) 3
• Fibrinogen levels (typically decreased due to consumption) 3
• D-dimer or other fibrin degradation products (elevated) 3

Additional Useful Tests

• Factor VIII and von Willebrand Factor levels (low or declining levels indicate consumptive coagulopathy) 3
• Antithrombin levels (declining levels suggest consumptive coagulopathy) 3

Monitoring Considerations

• Trend monitoring is critical as DIC is a dynamic process with rapidly changing laboratory values 3
• A 30% or higher drop in platelet count should be considered diagnostic of subclinical DIC even when absolute values remain in normal range 3
• Testing frequency should range from daily to monthly depending on clinical circumstances 3

Treatment Approach to DIC

Primary Treatment

• Treat the underlying condition - This is the cornerstone of DIC management 4
• Common underlying conditions include sepsis, trauma, malignancy, and obstetrical complications 2

Supportive Care for Bleeding Manifestations

• Platelet transfusion:

  • Consider when platelet count <50 × 10^9/L in actively bleeding patients 3, 4
  • Consider when platelet count <30 × 10^9/L in acute promyelocytic leukemia or <20 × 10^9/L in other cancers with high bleeding risk 3

• Fresh frozen plasma (FFP):

  • Administer in patients with active bleeding and prolonged PT/aPTT 3, 4
  • Should not be given based solely on laboratory tests 4

• Fibrinogen replacement:

  • Consider cryoprecipitate or fibrinogen concentrate when levels fall below 1.5 g/L in actively bleeding patients 3, 4

Management of Thrombotic Manifestations

• Anticoagulation:
  • Therapeutic doses of heparin should be considered when thrombosis predominates (arterial/venous thromboembolism, severe purpura fulminans) 4
  • Continuous infusion unfractionated heparin (UFH) at weight-adjusted doses (e.g., 10 μ/kg/h) may be beneficial due to its short half-life and reversibility 4
  • Prophylactic doses of heparin or low molecular weight heparin are recommended for critically ill, non-bleeding patients with DIC 4

Special Considerations

• Antifibrinolytic agents:

  • Generally not recommended in DIC 4
  • May be considered in patients with primary hyperfibrinolytic state and severe bleeding (tranexamic acid 1 g every 8 hours) 4

• Recombinant human activated protein C:

  • Consider for patients with severe sepsis and DIC (24 μg/kg/h for 4 days) 4
  • Contraindicated in patients at high risk of bleeding or with platelet counts <30 × 10^9/L 4

Clinical Pitfalls and Caveats

• Normal coagulation screen does not rule out DIC, and normal platelet count despite a significant drop from baseline can be misleading 3
• Liver disease can cause similar laboratory abnormalities but typically doesn't show the rapid changes characteristic of DIC 3
• Underlying malignancy can affect baseline laboratory values, making interpretation more challenging 3
• No gold standard for DIC diagnosis exists, making definitive comparison of diagnostic accuracy between different scoring systems challenging 1, 2
• The mortality of septic patients with DIC is approximately 24.8%, highlighting the importance of early diagnosis 2
• Different types of DIC exist based on the underlying cause, including sepsis-associated DIC, malignancy-associated DIC, and trauma-associated DIC 2

Emerging Considerations

• The ISTH is exploring the possibility of incorporating endothelium-related markers into diagnostic criteria to enable earlier detection and better management of DIC 1, 2
• Potential endothelium-related biomarkers include antithrombin activity and von Willebrand factor 1, 2
• The two-step approach using both SIC and overt DIC scoring systems may improve early identification of patients who might benefit from specific therapies 1