disseminated intravascular coagulation
Disseminated intravascular coagulation (DIC), also known as consumption coagulopathy or defibrination syndrome, refers to a systemic phenomenon of overactivation of coagulation and fibrinolysis resulting in widespread clots forming inside blood vessels.
Clinical presentation
Patients present with bleeding and/or thrombosis, as well as subsequent organ damage.
Pathology
During homeostasis, there is a balance between coagulation (formation of clots) and fibrinolysis (breakdown of clots).
During times of stress listed under "Etiology", this homeostasis is disrupted resulting in dysregulated coagulation and fibrinolysis. Widespread clotting occurs exhausting available clotting factors and platelets resulting in excess bleeding. An important mediator in this process is a transmembrane glycoprotein called tissue factor (TF).
Etiology
The commonest causes of disseminated intravascular coagulation are:
Markers
The diagnosis is supported by laboratory findings of coagulopathy and/or fibrinolysis including:
- low platelets
- low fibrinogen
- elevated D-dimer
- prolonged prothrombin time (PT)
- prolonged international normalized ratio (INR)
- prolonged activated partial thromboplastin time (aPTT)
- schistocytes on blood smear due to microangiopathic hemolytic anemia (MAHA)
Treatment and prognosis
Management focuses on treating the underlying condition. Supportive measures include helping the organs that are affected, such as:
- ventilator support
- hemodynamic support
- transfusions (platelets or red blood cells)
Complications
Disseminated intravascular coagulation may lead to:
- ischemia: insufficient blood flow (and subsequent lack of oxygen delivery) to tissue
- infarction: tissue death (by necrosis) due to inadequate blood supply
- damage to vital organs e.g. brain, lungs, liver, and kidneys
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