What are the findings that prompt treatment for Disseminated Intravascular Coagulation (DIC) and what is the appropriate treatment approach?

Findings That Prompt Treatment for DIC

When to Initiate Treatment

Treatment for DIC should be initiated when there is laboratory evidence of DIC (abnormalities in at least 3 of 4 tests: PT, platelet count, fibrinogen, D-dimer/FDPs) combined with either active bleeding, high bleeding risk (surgery/procedures), or thrombotic manifestations. 1, 2, 3

Laboratory Thresholds for Intervention

• A 30% or greater drop in platelet count from baseline indicates subclinical DIC progression and warrants consideration for treatment, even without overt bleeding 1, 2, 4
• Fibrinogen persistently <1.5 g/L despite supportive measures indicates need for fibrinogen replacement 1, 2, 4
• Platelet count <50×10⁹/L with active bleeding requires platelet transfusion 1, 2, 4
• Platelet count <30×10⁹/L in acute promyelocytic leukemia (APL) or <20×10⁹/L in other cancers with high bleeding risk (surgery/procedures) warrants platelet transfusion 1, 2

Clinical Scenarios Requiring Treatment

• Active bleeding with laboratory evidence of DIC 1, 2, 3
• Planned invasive procedures or surgery in patients with DIC 1, 2
• Thrombotic manifestations including arterial/venous thromboembolism, severe purpura fulminans with acral ischemia, or vascular skin infarction 3, 5
• Severe sepsis with DIC (specific considerations for activated protein C, though use is limited) 3

Important Caveats

• Do not transfuse prophylactically based solely on laboratory abnormalities in non-bleeding patients without high bleeding risk 2, 4, 6
• PT/aPTT may be normal in early or cancer-associated DIC, so do not rely solely on these tests—monitor trends in platelet count, fibrinogen, and D-dimer 1, 4
• Baseline thrombocytosis from malignancy can mask DIC; a decreasing trend is more important than absolute platelet values 4

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Appropriate Treatment for DIC

Cornerstone: Treat the Underlying Condition

The fundamental treatment of DIC is addressing the underlying trigger (sepsis, malignancy, trauma, obstetric complications)—all other measures are supportive. 1, 2, 4, 3, 5, 6

• In APL, early initiation of induction chemotherapy achieves excellent DIC resolution 1, 2
• In sepsis, source control and appropriate antibiotics are paramount 3, 5
• In obstetric DIC, delivery of the fetus/placenta is critical 3

Supportive Hemostatic Management

Platelet Transfusion

• Active bleeding: Maintain platelets >50×10⁹/L 1, 2, 4, 3
• High bleeding risk without active bleeding:
  • APL: Transfuse if <30×10⁹/L 1, 2
  • Other cancers/conditions: Transfuse if <20×10⁹/L 1, 2, 6
• Non-bleeding patients without high-risk procedures: Prophylactic transfusion generally not recommended unless platelet count drops below 20×10⁹/L 6
• Caveat: Transfused platelet lifespan may be very short (hours) due to ongoing consumption 1, 2

Fresh Frozen Plasma (FFP)

• Active bleeding with prolonged PT/aPTT: Administer 15-30 mL/kg 1, 2, 4, 3
• Monitor clinically for volume overload; if this is a concern, consider prothrombin complex concentrates (though these only partially correct the defect as they lack all coagulation factors) 1, 3
• Do not give FFP based on laboratory values alone without bleeding or planned procedures 3, 6

Fibrinogen Replacement

• If fibrinogen remains <1.5 g/L despite FFP: Administer 2 pools of cryoprecipitate or fibrinogen concentrate 1, 2, 4, 3
• This threshold applies specifically to patients with active bleeding 1, 2

Anticoagulation Strategy

Heparin Indications

Therapeutic-dose heparin is indicated primarily in thrombotic-predominant DIC (arterial/venous thromboembolism, severe purpura fulminans, vascular skin infarction). 1, 3, 5

• Contraindications to therapeutic heparin:
  • Active bleeding 1, 3, 5
  • Platelet count <20×10⁹/L 1, 2, 4
  • Hyperfibrinolytic DIC (e.g., certain leukemias, trauma) 2, 5

Prophylactic Anticoagulation

• Critically ill, non-bleeding patients with DIC: Prophylactic-dose unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) is recommended for venous thromboembolism prevention 1, 3, 5, 6
• Discontinue prophylaxis if:
  • Active bleeding develops 6
  • Platelet count drops below 20-30×10⁹/L 1, 6

Heparin Selection

• High bleeding risk with renal failure: Prefer UFH due to short half-life and reversibility 2, 3
• Other cases: LMWH is preferred 2
• Solid tumor-associated thrombotic DIC: LMWH at therapeutic doses for 6 months (full dose first month, then 75% dose for 5 months) is superior to warfarin 2

FDA-Approved Indication

• Heparin is FDA-approved for "treatment of acute and chronic consumptive coagulopathies (disseminated intravascular coagulation)" 7
• Dosing for therapeutic anticoagulation: Initial IV bolus 10,000 units, then 5,000-10,000 units every 4-6 hours or continuous infusion 20,000-40,000 units/24 hours 7

Monitoring During Treatment

• Acute DIC: Daily monitoring of CBC, PT/aPTT, fibrinogen, and D-dimer 2, 4, 7
• Cancer-associated DIC: Frequency varies from daily to monthly based on clinical stability 1, 2
• Heparin therapy: Monitor aPTT every 4 hours initially when using continuous infusion, then at appropriate intervals 7
• Platelet monitoring: Essential throughout treatment to detect heparin-induced thrombocytopenia 7

Agents Generally NOT Recommended

• Antifibrinolytic agents (tranexamic acid): Generally contraindicated in DIC except in cases with severe bleeding characterized by marked hyperfibrinolysis (certain leukemias, trauma) 3, 5
• Antithrombin concentrate: Cannot be recommended without further RCT evidence showing benefit on clinical endpoints 3, 5
• Recombinant activated protein C: May be considered in severe sepsis with DIC, but contraindicated if platelet count <30×10⁹/L or high bleeding risk 3

Key Pitfalls to Avoid

• Do not withhold anticoagulation solely based on abnormal coagulation tests if thrombosis predominates and there is no active bleeding 2, 4
• Do not give prophylactic blood products to "correct" laboratory values in non-bleeding patients without procedures 2, 4, 3, 6
• Recognize that transfused products have very short half-lives in DIC with vigorous coagulation activation—repeated dosing may be necessary 1, 2
• Monitor for the underlying condition's response to treatment—failure of DIC to improve suggests inadequate treatment of the trigger 1, 2, 3