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