Disseminated Intravascular Coagulation (DIC)

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management

Definition

Disseminated intravascular coagulation (DIC) is a systemic disorder characterised by widespread activation of the coagulation cascade, leading to microvascular thrombosis, consumption of clotting factors, and subsequent bleeding.

Aetiology

  • Sepsis: most common cause (e.g., bacterial endotoxins trigger coagulation).
  • Obstetric complications: amniotic fluid embolism, placental abruption.
  • Malignancies: leukaemia, metastatic cancers.
  • Trauma: massive burns, head injuries, crush injuries.
  • Haemolytic transfusion reaction: ABO incompatibility.
  • Severe liver disease: reduced synthesis of clotting factors.

Pathophysiology

  • Systemic activation of coagulation leads to widespread fibrin deposition in the microvasculature.
  • Consumption of clotting factors and platelets results in bleeding tendency.
  • Fibrinolysis is simultaneously activated, producing excess fibrin degradation products (D-dimers).

Risk Factors

  • Severe infections or sepsis.
  • Major trauma or surgery.
  • Advanced malignancy.
  • Obstetric emergencies.
  • Massive transfusion.

Signs and Symptoms

  • Bleeding from multiple sites (mucosal, intravenous lines, surgical wounds).
  • Purpura, petechiae, ecchymoses.
  • Shock in severe cases due to haemorrhage.
  • End-organ dysfunction (renal failure, respiratory distress, altered mental status).
  • Thrombosis leading to digital ischaemia and gangrene.

Investigations

  • Full blood count (FBC): thrombocytopenia.
  • Coagulation studies: prolonged PT, APTT.
  • D-dimer: markedly elevated due to fibrinolysis.
  • Fibrinogen: low due to consumption.
  • Blood film: schistocytes (fragmented red cells) in microangiopathic haemolytic anaemia.

Management

1. Treat Underlying Cause:

  • Antibiotics for sepsis.
  • Delivery in obstetric emergencies.
  • Oncological management in malignancy-associated DIC.

2. Supportive Therapy:

  • Fresh frozen plasma (FFP) for severe coagulopathy.
  • Platelet transfusions if <20 x 10⁹/L and bleeding.
  • Cryoprecipitate for low fibrinogen levels (<1 g/L).
  • Heparin in cases of predominant thrombosis.

3. Referral:

  • Haematology: for coagulation disorder management.
  • Intensive care: if haemodynamic instability or multi-organ failure.
  • Obstetrics: if pregnancy-related DIC.
HaematologymypanotesDisseminated Intravascular Coagulation (DIC)