Disseminated Intravascular Coagulation

Basics

Description

  • 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.

Epidemiology

  • Most commonly secondary to infections
  • Overall incidence is difficult to determine secondary to the many conditions that cause DIC.

Pathophysiology

  • 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.

Etiology

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
    • Viral
  • Trauma
    • Multiple fractures with fat emboli
    • Massive soft tissue injury
    • Severe head trauma
    • Multiple gunshot wounds
  • Malignancies
    • Acute promyelocytic leukemia
    • Widespread solid tumors (e.g., neuroblastoma, adenocarcinoma)
  • Obstetric
    • Retained intrauterine fetal demise
    • Preeclampsia/eclampsia
    • Amniotic fluid embolism
    • Abruptio placentae
    • Posthemorrhagic shock
  • Neonatal
    • 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
  • Miscellaneous
    • 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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