Disseminated Intravascular Coagulation
- Disseminated intravascular coagulation (DIC) is an acquired syndrome that is always secondary to an underlying etiology.
- It is a systemic life-threatening process characterized by an uncontrolled activation of the coagulation and fibrinolytic systems with excessive thrombin generation and the consumption of coagulation factors and platelets.
- Widespread deposition of microthrombi can compromise perfusion and lead to organ failure.
- Ongoing activation and consumption of coagulant factors and platelets can result in diffuse and profuse bleeding.
- Most commonly secondary to infections
- Overall incidence is difficult to determine secondary to the many conditions that cause DIC.
- Not a disorder in itself; occurs as a result of various initiating events
- Characterized by microvascular thrombosis and hemorrhage
- May be acute (e.g., meningococcemia) or chronic (e.g., malignancy/leukemia)
- There is a systemic intravascular deposition of fibrin as a result of increased thrombin generation, suppression of anticoagulant pathways, impaired fibrinolysis, and activation of inflammatory pathways.
- The initiation of coagulation activation leading to thrombin formation in DIC is mediated via the tissue factor/factor VIIa pathway.
- The tissue factor/factor VIIa pathway is activated via tissue factor expression from damaged endothelial cells.
- Anticoagulant pathways are diminished because of a decrease in the plasma levels of antithrombin and the protein C system through impaired production and increased destruction.
- The increase in fibrinolytic activity is likely secondary to the release of plasminogen activators from damaged endothelial cells.
Most common causes are sepsis (particularly gram-negative), hypotensive shock, and trauma.
- Sepsis/severe infection
- Bacterial: gram-negative and gram-positive
- Malaria: Plasmodium falciparum
- Fungal: Aspergillus
- Rickettsial: Rocky Mountain spotted fever
- Multiple fractures with fat emboli
- Massive soft tissue injury
- Severe head trauma
- Multiple gunshot wounds
- Acute promyelocytic leukemia
- Widespread solid tumors (e.g., neuroblastoma, adenocarcinoma)
- Retained intrauterine fetal demise
- Amniotic fluid embolism
- Abruptio placentae
- Posthemorrhagic shock
- Necrotizing enterocolitis
- Perinatal asphyxia
- Amniotic fluid aspiration
- Obstetric complications (see above)
- Sepsis (bacterial and viral)
- Erythroblastosis fetalis
- Respiratory distress syndrome
- Vascular malformations
- Kasabach-Merritt syndrome
- Large vascular aneurysms
- Acute hemolytic transfusion reaction
- Snake bite
- Homozygous protein C/S deficiency (purpura fulminans)
- Transplant rejection
- Severe collagen vascular disease
- Recreational drugs
- Profound shock or asphyxia
- Hypothermia or hyperthermia
- Extensive burn injuries
- Fulminant hepatitis/hepatic failure
- Severe pancreatitis
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