What are the diagnostic criteria and management strategies for Disseminated Intravascular Coagulation (DIC)?

Diagnostic Criteria and Management Strategies for Disseminated Intravascular Coagulation (DIC)

The diagnosis of DIC should be based on standardized scoring systems, primarily the ISTH overt DIC criteria, which includes platelet count, prothrombin time, fibrin-related markers, and fibrinogen levels, with management focused on treating the underlying cause and providing appropriate supportive care based on clinical presentation. 1

Diagnostic Criteria for DIC

ISTH Overt DIC Scoring System

The International Society on Thrombosis and Haemostasis (ISTH) overt DIC scoring system is the most widely used diagnostic tool:

Parameter	Score	Range
Platelet count (×10⁹/L)	2	<50
	1	≥50, <100
FDP/D-dimer	3	Strong increase
	2	Moderate increase
Prothrombin time (PT ratio)	2	≥6 s (>1.4)
	1	≥3 s, <6 s (>1.2, ≤1.4)
Fibrinogen (g/mL)	1	<100
Total score for DIC diagnosis	≥5

A score of ≥5 indicates overt DIC 1

Sepsis-Induced Coagulopathy (SIC) Criteria

For sepsis-related cases, the SIC scoring system identifies an earlier phase of DIC:

Parameter	Score	Range
Platelet count (×10⁹/L)	2	<100
	1	≥100, <150
PT-INR	2	>1.4
	1	>1.2, ≤1.4
SOFA score	2	≥2
	1	1
Total score for SIC diagnosis	≥4

SOFA score includes respiratory, cardiovascular, hepatic, and renal components 1

Important Diagnostic Considerations

• Serial monitoring is essential as DIC is a dynamic process
• No gold standard exists for DIC diagnosis, making comparative evaluation of different scoring systems challenging 1
• Consider the underlying cause when interpreting laboratory results, as different etiologies can present with varying laboratory patterns 1
• In cancer-associated DIC, a 30% or higher drop in platelet count may be considered diagnostic of subclinical DIC even without clinical manifestations 1

Management Strategies for DIC

Cornerstone of Treatment

• Treatment of the underlying condition is the primary goal 1
• This is exemplified by the resolution of DIC in patients with acute promyelocytic leukemia (APL) after induction therapy 1

Supportive Care for Bleeding Manifestations

For patients with active bleeding:

• Platelet transfusion to maintain count above 50 × 10⁹/L 1, 2
• Fresh frozen plasma (15-30 mL/kg) for prolonged PT and aPTT 1, 2
• Consider prothrombin complex concentrate if volume overload is a concern 1
• For persistent hypofibrinogenemia (<1.5 g/L), administer cryoprecipitate or fibrinogen concentrate 1, 2

For patients at high risk of bleeding (e.g., surgery or invasive procedures):

• Platelet transfusion if count is <30 × 10⁹/L in APL or <20 × 10⁹/L in other cancers 1
• Avoid prophylactic platelet transfusion in non-bleeding patients unless high risk of bleeding 2

Anticoagulant Therapy

• For DIC where thrombosis predominates (arterial/venous thromboembolism, purpura fulminans, vascular skin infarction):

  • Consider therapeutic doses of heparin 2
  • Unfractionated heparin (UFH) may be preferred when bleeding risk is high due to short half-life (10 μ/kg/h) 2

• For critically ill, non-bleeding patients with DIC:

  • Prophylactic doses of heparin or low molecular weight heparin (LMWH) are recommended 2

• For sepsis-associated DIC:

  • Anticoagulant therapy remains controversial 1
  • Heparin (UFH or LMWH) may be considered for thromboprophylaxis 1

• For cancer-associated DIC:

  • Consider prophylactic heparin in the absence of contraindications (platelet count <20 × 10⁹/L or active bleeding) 1
  • Avoid heparin in hyperfibrinolytic DIC 1

Antifibrinolytic Therapy

• Generally, patients with DIC should not be treated with antifibrinolytic agents 2
• Exception: Patients with primary hyperfibrinolytic state and severe bleeding may be treated with tranexamic acid (1 g every 8 hours) 2

Special Considerations for Different DIC Types

Sepsis-Induced DIC

• Characterized by excessive suppression of fibrinolysis due to plasminogen activator inhibitor-1 overproduction 1
• Organ dysfunction often develops due to reduced tissue perfusion 1
• Hypofibrinogenemia is not common, and fibrin-related marker elevation doesn't correlate with severity 1
• Platelet count decline and PT prolongation correlate with increased mortality 1

Cancer-Associated DIC

• Presentation varies based on cancer type
• Malignancy-associated DIC typically doesn't show fibrinolysis suppression seen in sepsis 1
• More likely to present with systemic bleeding 1
• Requires frequent monitoring of laboratory parameters 1

Endothelial Involvement in DIC

• Endothelial injury is an essential component of DIC pathophysiology 1
• Current diagnostic criteria don't include specific endothelial biomarkers 1
• Antithrombin activity and von Willebrand factor could be potential markers of endothelial injury 1
• The degree of endothelial dysfunction varies by underlying disease: significant in sepsis, moderate in trauma, and variable in hematologic malignancies 1

Common Pitfalls and Caveats

• Transfused platelets and fibrinogen may have very short lifespans in DIC with vigorous coagulation activation 1
• Laboratory tests alone should not guide transfusion decisions; clinical assessment is crucial 2
• Abnormalities in clotting screens by themselves should not trigger treatment with blood products 1
• Monitoring APTT in patients receiving heparin may be complicated; clinical observation for bleeding signs is important 2
• DIC scoring systems help identify patients who might benefit from specific therapies and evaluate treatment effects 1