DIC Syndrome Calculator

What Is the ISTH DIC Score?

The International Society on Thrombosis and Haemostasis (ISTH) DIC scoring system helps identify overt disseminated intravascular coagulation (DIC). It combines four laboratory parameters: platelet count, fibrin-related marker elevation (D-dimer or fibrin degradation products), prothrombin time prolongation, and fibrinogen level. The total score ranges from 0 to 8 and supports diagnosis and monitoring in sepsis, trauma, malignancy, and other precipitating conditions.

Scoring Components

Platelets above 100 × 10⁹/L score 0 points; 50 to 100 score 1; below 50 score 2. Fibrin marker increase scores 0 (none), 2 (moderate), or 3 (strong). PT prolongation less than 3 seconds scores 0; 3 to 6 seconds scores 1; greater than 6 seconds scores 2. Fibrinogen above 1.0 g/L scores 0; 1.0 g/L or less scores 1. Repeat assessment within 24 hours when the score is 3 or 4 because DIC may evolve rapidly.

Score Interpretation

A score below 3 suggests DIC is not probable. Scores of 3 or 4 indicate non-overt DIC is possible and warrant repeat labs. A score of 5 or higher is compatible with overt DIC and requires urgent treatment of the underlying cause plus supportive blood product management guided by bleeding and thrombosis risk.