What clinical signs and laboratory findings should I look for to diagnose disseminated intravascular coagulation (DIC) in a patient?

Clinical signs to assess for disseminated intravascular coagulation (DIC) include bleeding manifestations such as petechiae, ecchymoses, oozing from venepuncture sites, and mucosal bleeding, as well as signs of thrombosis like digital ischemia or organ dysfunction due to microvascular thrombosis. Patients may also present with symptoms related to the underlying cause, such as sepsis or malignancy, which often precipitate DIC ¹ (Iba et al., 2023).

Laboratory findings essential for diagnosing DIC involve a combination of coagulation abnormalities: prolonged prothrombin time (PT) and activated partial thromboplastin time (aPTT), thrombocytopenia, decreased fibrinogen levels, and elevated fibrin degradation products including D-dimer. These reflect the consumption of clotting factors and platelets alongside increased fibrinolysis ¹ (Bick, 1996; Scarlatescu et al., 2024).

Specifically, a scoring system integrating platelet count, PT prolongation, fibrinogen concentration, and D-dimer or fibrin degradation products is recommended to improve diagnostic accuracy ¹. The presence of elevated D-dimer is a sensitive marker of fibrin formation and breakdown but is not specific to DIC alone (Iba et al., 2023). Low fibrinogen is a key indicator of consumption coagulopathy, although it may be elevated in inflammatory states, so clinical correlation is essential (Scarlatescu et al., 2024).

In summary, diagnosis of DIC requires careful clinical assessment for bleeding and thrombotic signs combined with laboratory evidence of coagulation activation and consumption, using a validated scoring system to confirm the diagnosis ¹ (Bick, 1996; Iba et al., 2023; Scarlatescu et al., 2024).