From the Guidelines
Serum testing for Disseminated Intravascular Coagulation (DIC) should include a panel of laboratory tests, with the most important being platelet count, prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen levels, and D-dimer or fibrin degradation products (FDPs), as recommended by the International Society on Thrombosis and Haemostasis (ISTH) 1.
Key Laboratory Tests
- Platelet count
- Prothrombin time (PT)
- Activated partial thromboplastin time (aPTT)
- Fibrinogen levels
- D-dimer or fibrin degradation products (FDPs) These tests are crucial in diagnosing DIC, as they reflect the simultaneous excessive clotting and bleeding that characterizes the condition.
Additional Helpful Tests
Additional tests that may be helpful in diagnosing DIC include:
- Peripheral blood smear to look for schistocytes (fragmented red blood cells)
- Thrombin time
- Specific factor assays like antithrombin III
Importance of Serial Measurements
Serial measurements of these laboratory tests are often necessary to monitor disease progression or response to treatment, as recommended by the ISTH 1 and other societies such as the American Society of Hematology (ASH) 1.
ISTH DIC Scoring System
The ISTH DIC scoring system uses these laboratory values to calculate a score that helps confirm the diagnosis of DIC, with a score of 5 or more indicating overt DIC 1.
Clinical Practice Recommendations
In clinical practice, testing should be performed promptly when DIC is suspected, as early diagnosis and treatment of the underlying cause (such as sepsis, trauma, or malignancy) is crucial for improving outcomes, as emphasized by the ASH 1 and the International Society for Thrombosis and Haemostasis’s interim guidance (ISTH-IG) 1.
Recent Guidelines
Recent guidelines from the ISTH-IG and ASH recommend monitoring D-dimer, PT, platelet count, and fibrinogen levels for risk stratification of critically ill patients with COVID-19, as these measurements may be helpful in identifying patients who require close monitoring and admission to hospital 1.
From the Research
Serum Testing for DIC
Serum testing for Disseminated Intravascular Coagulation (DIC) involves a combination of laboratory tests to diagnose and monitor the condition. The following tests are commonly used:
- Prothrombin time (PT) and activated partial thromboplastin time (aPTT) to assess coagulation activation and consumption of coagulation factors 2, 3, 4, 5
- Fibrinogen and fibrin degradation products (FDP) to evaluate fibrinolysis and coagulation activation 6, 3, 4, 5
- D-dimer assay to measure cross-linked fibrin degradation products and assess coagulation and fibrinolysis activation 6, 4, 5
- Antithrombin and protein C levels to assess natural anticoagulants 4, 5
- Fibrinopeptide-A level to evaluate coagulation activation 6
- Thrombin-antithrombin complex (TAT) and plasmin-α2 plasmin inhibitor (PIC) to assess coagulation and fibrinolysis activation 3
Diagnostic Efficiency of Serum Tests
The diagnostic efficiency of serum tests for DIC varies:
- D-dimer assay has a high sensitivity (91-93.7%) and specificity (68-94%) 6, 4
- FDP has a high sensitivity (83.7-100%) and moderate specificity (67-71%) 6, 4
- PT and aPTT have limited diagnostic efficiency due to low specificity and sensitivity 4, 5
- Antithrombin and protein C levels are useful in assessing the severity and prognosis of DIC, but are not normally incorporated into standard diagnostic algorithms 5
Combination of Serum Tests
A combination of serum tests is recommended for the diagnosis of DIC:
- D-dimer and FDP tests offer the best test panel in the diagnosis of DIC 4
- PT, aPTT, and fibrinogen are useful in assessing coagulation activation and consumption of coagulation factors, but have limited diagnostic efficiency when used alone 2, 3, 4, 5
- Antithrombin and protein C levels are useful in assessing the severity and prognosis of DIC 5