Disseminated intravascular coagulation - Clotting disorders

Disseminated intravascular coagulation

Definition

Disseminated intravascular coagulation (DIC) is a generalised activation of the coagulation system causing widespread generation of fibrin within blood vessels and consumption of clotting factors.

Aetiology

Causes include Gram −ve and meningococcal septicaemia, disseminated malignant disease, haemolytic transfusion reactions, trauma, burns, surgery and P. falciparum malaria.

Pathophysiology

Widespread activation of intrinsic, extrinsic pathways and platelet aggregation causes consumption of platelets and clotting factors (a consumptive coagulopathy) resulting in a severe bleeding risk. Fibrin is deposited in small vessels within the brain, kidney and lungs causing ischaemic damage. Red cells are fragmented during passage through occluded vessels causing a micro angiopathic haemolytic picture.

Clinical features

The first signs may be bleeding into the tissues particularly mouth, nose and at venepuncture sites. Patients are shocked and acutely ill, they develop multi organ ischaemia and dysfunction.

Investigations

Coagulation studies reveal prolonged clotting times and low fibrinogen levels.

Fibrinogen degradation products are raised (D-dimer).

There is thrombocytopenia, blood film reveals fragmented red blood cells.

Management

DIC is managed by treating the underlying cause and blood components using platelets, fresh frozen plasma, cryoprecipitate and red cell concentrates. Patients require supportive care and normally are managed in intensive care units.