Disseminated Intravascular Coagulation

GENERAL PRINCIPLES

Etiology

DIC occurs in a variety of systemic illnesses that include sepsis, trauma, burns, shock, obstetric complications, and malignancies (notably, acute promyelocytic leukemia).

Pathophysiology

Exposure of tissue factor to the circulation generates excess thrombin, leading to platelet activation, consumption of coagulation factors (including fibrinogen) and regulators (antithrombin [AT] and proteins C and S), fibrin generation, generalized microthrombi, and reactive fibrinolysis.

DIAGNOSIS

Clinical Presentation

Consequences of DIC include bleeding, organ dysfunction secondary to microvascular thrombi and ischemia, and less often, large arterial and venous thrombosis.⁴⁶

Diagnostic Testing

No test confirms diagnosis of DIC. The International Society on Thrombosis and Haemostasis (ISTH) devised a clinical scoring system for objective detection of DIC (Table 20-4). Serial “DIC panels” help assess clinical management and prognosis.

TABLE 20-4

INTERNATIONAL SOCIETY ON THROMBOSIS AND HAEMOSTASIS DISSEMINATED INTRAVASCULAR COAGULATION SCORING SYSTEM

Use Only in Patients With an Underlying Condition Known to be Associated With DIC.

Sum the points for each of the four categories to determine the clinical probability of having DIC: compatible with overt DIC #8805;5 points, and suggestive of nonovert DIC lt;5 points.

DIC, disseminated intravascular coagulation.

Data from Taylor FB Jr, Toh CH, Hoots WK, et al. Towards definition, clinical and laboratory criteria, and a scoring system for disseminated intravascular coagulation. Thromb Haemost. 2001;86(5):1327-1330 and Bakhtiari K, Meijers JC, de Jonge E, Levi M. Prospective validation of the International Society of Thrombosis and Haemostasis scoring system for disseminated intravascular coagulation. CritCare Med. 2004;32(12):2416-2421.

TREATMENT

Treatment of DIC consists of supportive care and correction of the underlying disorder if possible. FFP, cryoprecipitate, and platelets can be administered when needed clinically (e.g., bleeding or surgery), rather than strictly based on a laboratory threshold. Despite the coagulopathy, patients who have large- vessel venous or arterial thrombi should undergo anticoagulation if they do not have other contraindications. Nonbleeding patients who have DIC should receive thromboprophylaxis with heparin.