Diagnostic Criteria for Disseminated Intravascular Coagulation (DIC)
The diagnosis of DIC requires using the International Society on Thrombosis and Haemostasis (ISTH) overt DIC scoring system, which diagnoses DIC when a score of ≥5 points is reached based on platelet count, fibrin-related markers, prothrombin time, and fibrinogen levels. 1
ISTH Overt DIC Scoring System
The ISTH overt DIC scoring system includes the following parameters:
Platelet count:
- 2 points: <50 × 10^9/L
- 1 point: ≥50, <100 × 10^9/L 1
Fibrin-related markers (D-dimer or FDP):
- 3 points: Strong increase
- 2 points: Moderate increase 1
Prothrombin time (PT) prolongation:
- 2 points: ≥6 seconds above normal or PT ratio >1.4
- 1 point: ≥3 seconds, <6 seconds above normal or PT ratio >1.2, ≤1.4 1
Fibrinogen level:
- 1 point: <100 mg/dL 1
Total score for DIC diagnosis: ≥5 points 1
Sepsis-Induced Coagulopathy (SIC) Scoring System
For earlier detection of DIC specifically in sepsis patients, the ISTH recommends the SIC scoring system:
Platelet count:
- 2 points: <100 × 10^9/L
- 1 point: ≥100, <150 × 10^9/L 1
Prothrombin time (PT ratio):
- 2 points: >1.4
- 1 point: >1.2, ≤1.4 1
SOFA score (Sequential Organ Failure Assessment):
- 2 points: ≥2
- 1 point: 1 1
Total score for SIC diagnosis: ≥4 points 1
Clinical Considerations for DIC Diagnosis
DIC is not a primary disease but a syndrome secondary to underlying conditions such as sepsis, trauma, malignancy, or obstetrical complications 1
The diagnosis should encompass both clinical and laboratory information, and tests should be repeated to monitor the dynamically changing scenario 2
No single test is sufficiently accurate to establish or rule out a diagnosis of DIC, which is why a scoring system using a combination of laboratory tests is necessary 3
Different types of DIC exist based on the underlying cause, including sepsis-associated DIC, malignancy-associated DIC, and trauma-associated DIC 1
The mortality of septic patients with DIC is approximately 24.8%, highlighting the importance of early diagnosis 1
Importance of Identifying the Underlying Condition
The cornerstone of DIC treatment is addressing the underlying condition 2
Most cases are due to pathological activation of the intrinsic coagulation systems (e.g., in sepsis), and/or the extrinsic system (e.g., in malignancy and head trauma) 4
DIC can be categorized into bleeding, organ failure, massive bleeding, and non-symptomatic types according to the sum of vectors for hypercoagulation and hyperfibrinolysis 5
Emerging Considerations in DIC Diagnosis
The ISTH is exploring the incorporation of endothelium-related markers into diagnostic criteria to enable earlier detection and better management of DIC 1
Endothelial injury is an essential component of DIC pathophysiology but is not currently included in diagnostic criteria 1
Potential endothelium-related biomarkers that may improve future diagnostic criteria include antithrombin activity and von Willebrand factor 1