How can I tell if my patient with a trigger (sepsis, trauma, obstetric complication, malignancy, major surgery, or burns) has DIC (disseminated intravascular coagulation)?

How to Diagnose DIC in Your Patient

Use the ISTH overt-DIC scoring system (≥5 points confirms diagnosis) in any patient with an appropriate trigger condition (sepsis, trauma, obstetric complication, malignancy, major surgery, or burns) who shows laboratory evidence of consumptive coagulopathy. 1, 2

Step 1: Confirm an Underlying Trigger Condition

DIC is never a primary disease—it always requires an underlying cause. 3 The most common triggers include:

• Sepsis (most common cause overall) 3
• Malignancy (especially pancreatic cancer, adenocarcinomas, acute promyelocytic leukemia, metastatic prostate cancer) 2, 3
• Trauma and major surgery 3
• Obstetric complications (placental abruption, amniotic fluid embolism, severe preeclampsia, acute fatty liver of pregnancy) 3, 4
• Burns 3

Without one of these triggers, reconsider the diagnosis. 3

Step 2: Apply the ISTH Overt-DIC Scoring System

The ISTH overt-DIC score is the validated gold standard for diagnosis. 1, 2 A score ≥5 points confirms overt DIC. 1, 2

Scoring Components:

Platelet count: 1

• <50 × 10⁹/L = 2 points
• ≥50 to <100 × 10⁹/L = 1 point

Fibrin-related markers (D-dimer/FDP): 1

• Strong increase = 3 points
• Moderate increase = 2 points

Prothrombin time prolongation: 1

• ≥6 seconds (PT ratio >1.4) = 2 points
• ≥3 to <6 seconds (PT ratio >1.2 to ≤1.4) = 1 point

Fibrinogen level: 2

• Decreased (typically <1 g/L in severe cases) = additional consideration

Step 3: Recognize Critical Diagnostic Pitfalls

A normal platelet count does NOT rule out DIC if the patient had initially elevated platelets. 2, 3 A ≥30% drop in platelet count is diagnostic of subclinical DIC even when absolute values remain in the normal range. 2, 3

PT and aPTT may be normal in cancer-associated DIC, especially subclinical forms. 3 Normal coagulation screens were found in approximately 50% of septic DIC cases. 3

Single laboratory values are less important than trends over time. 2 Dynamic monitoring over hours to days is more diagnostically valuable than isolated measurements. 2

Step 4: Identify the Clinical Phenotype

DIC presents in three distinct patterns that guide both diagnosis and management: 3

Procoagulant (Thrombotic) DIC:

• Associated conditions: Pancreatic cancer, adenocarcinomas 2, 3
• Clinical signs: Arterial ischemia, poor digital circulation, venous thromboembolism, microvascular thrombosis, cerebrovascular manifestations 2, 3

Hyperfibrinolytic (Bleeding) DIC:

• Associated conditions: Acute promyelocytic leukemia, metastatic prostate cancer 2, 3
• Clinical signs: Widespread bruising, bleeding from mucosal surfaces (gums, nose, GI tract), bleeding from venipuncture sites, CNS hemorrhage 2, 3

Subclinical DIC:

• Laboratory findings: ≥30% platelet drop, elevated D-dimer, mild coagulation factor consumption 2
• Clinical presentation: No obvious bleeding or thrombosis, only laboratory abnormalities 2

Step 5: Consider Additional Confirmatory Tests for Uncertain Cases

When the diagnosis remains unclear despite scoring: 3

• Factor VIII and von Willebrand factor: Low or declining levels confirm consumptive coagulopathy (distinguishes DIC from chronic liver disease, where these are normal or elevated) 3
• Antithrombin levels: Decreased in DIC due to consumption 1

Step 6: Differentiate DIC from Chronic Liver Disease

This is a common diagnostic challenge. Key distinguishing features: 3

Feature	DIC	Chronic Liver Disease
Underlying trigger required	Yes [3]	No [3]
Organ involvement	Multiorgan failure from disseminated thrombi [3]	Usually not multisystem [3]
Laboratory changes	Rapid (hours to days) [3]	Stable or slowly progressive [3]
Factor VIII/VWF	Low or declining [3]	Normal or elevated [3]

Step 7: Establish Monitoring Frequency Based on Clinical Severity

Daily monitoring: Acute severe DIC with active bleeding or rapid clinical deterioration 2

Every 2-3 days: Stable ICU patients with diagnosed DIC 2

Weekly: Hospitalized patients with chronic DIC (e.g., cancer-associated) 2

Monthly: Outpatients with stable subclinical DIC 2

Key Laboratory Tests to Order

Essential initial panel: 5, 6, 7

• Complete blood count with platelet count
• Prothrombin time (PT)
• Activated partial thromboplastin time (aPTT)
• Fibrinogen level
• D-dimer or fibrin degradation products (FDP)

D-dimer is highly sensitive for DIC and indicates active fibrinolysis. 2 Elevated D-dimer combined with thrombocytopenia in the appropriate clinical context strongly suggests DIC. 2, 6, 7

Common Pitfall to Avoid

Do not wait for all laboratory values to be severely abnormal before diagnosing DIC. 1 Early recognition using the SIC (sepsis-induced coagulopathy) criteria may identify patients in the compensated phase who could benefit from earlier intervention. 1 The SIC criteria use platelet count, PT ratio, and SOFA score to identify earlier-stage coagulopathy in septic patients. 1