ISTH Criteria for Disseminated Intravascular Coagulation (DIC)

ISTH DIC Score Calculator

Platelet Count

Elevated Fibrin Markers (D-dimer)

Prolonged PT

Fibrinogen Level

ISTH DIC Score: 0

Not Overt DIC

Score 0: Suggestive but not affirmative for overt DIC. Repeat scoring in 1–2 days. Monitor closely.

Diagnoses overt disseminated intravascular coagulation (DIC).

Why Use

DIC is a syndrome which complicates a range of diseases. It is characterized by systemic activation of pathways leading to generation of fibrin clots that may cause organ failure with concomitant consumption of platelets and coagulation factors that may result in clinical bleeding. This calculator can aid in the determination of possible overt DIC and non-overt DIC in patients with underlying conditions that may be associated with DIC.

When to Use

Patients with suspected overt disseminated intravascular coagulopathy (DIC), e.g. in the setting of malignancy, severe infection or sepsis, obstetric complications, trauma.

Formula

Diagnostic criteria for overt DIC (patient has to have an underlying disorder known to be associated with overt DIC to use this algorithm): Variable Points Platelet count, cells x 10 9 /L ≥100 0 50 to <100 1 <50 2 Elevated levels of a fibrin-related marker* (e.g. D-dimer, fibrin degradation products) No increase 0 Moderate increase 2 Severe increase 3 Prolonged PT , seconds <3 0 3 to <6 1 ≥6 2 Fibrinogen level, g/L ≥1 0 <1 1 *Use lab-specific cutoff values.

Pearls / Pitfalls

The presence of disease known to be associated with DIC (e.g. malignancy, severe infection or sepsis, obstetric complications, trauma) is a prerequisite for the use of this scoring system. Increasing scores strongly correlate with higher mortality rates. The coagulation profile (platelet count, PT , D-dimer, fibrinogen) provide a glimpse of the dynamic nature of DIC. It is important to repeat the tests serially for monitoring. This scoring system may not be appropriate for all patients, and individual patient circumstances may indicate an alternative method. For example, if bleeding is suspected due to liver dysfunction vs DIC, liver function tests and some coagulation factors may be more appropriate to confirm the clinical suspicion.

Management

DIC results as a complication to a wide spectrum of disorders. It is crucial to identify the underlying clinical disorder for appropriate management. DIC Score <5 - not suggestive of overt DIC, may be non-overt DIC; repeat within next 1-2 days and manage clinically as appropriate. DIC Score ≥5 - compatible with overt DIC; treat for DIC as appropriate and repeat scoring daily.

Critical Actions

Comprehensive decision making should not be based only on this scoring system.

Advice

Diagnosis of DIC should be made based on an appropriate clinical suspicion supported by relevant laboratory tests.

More Information

Interpretation: Score Diagnosis <5 Not suggestive of overt DIC, may be non-overt DIC; repeat within next 1-2 days and manage clinically as appropriate ≥5 Compatible with overt DIC; treat for DIC as appropriate and repeat scoring daily