Disseminated Intravascular Coagulation (DIC)

Snapshot

• A 35-year-old man with a history of alcoholism is brought to the emergency room after being found clutching his abdomen at a grocery store. He is currently intoxicated. He reports significant pain in his epigastrium. A complete blood count shows anemia and thrombocytopenia. Lipase and amylase levels are both elevated. A peripheral blood smear shows schistocytes. Additional lab testing reveals elevated D-dimer and low fibronigen levels. (Pancreatitis-induced disseminated intravascular coagulation)

Introduction

• Overview
  • disseminated intravascular coagulation (DIC) is characterized by abnormal widespread activation of clotting
• Epidemiology
  • incidence
    • ~1% of all hospitalizations
  • risk factors 
    • trauma
    • sepsis
      • particularly with gram-negative bacteria
    • obstetrical complications
    • acute pancreatitis
    • malignancy
    • nephrotic syndrome
    • transfusions
• Pathogenesis
  • mechanism
    • abnormal activation of coagulation cascade leads to thrombi production, which leads to consumption coagulopathy
    • fibrinolysis occurs at sites of thrombi, and fibrin degeneration products can interfere with coagulation
      • leads to end-organ damage
    • consumption coagulopathy exceeds production of clotting factors
• in chronic cases, there may be compensation via increased production

Presentation

• Physical exam
  • inspection
    • bleeding and oozing at catheter sites and mucosal surfaces
    • purpura fulminans
      • retiform purpura, particularly at acral sites
    • petechiae and ecchymoses
    • altered mental status
  • vital signs
    • hypotension
• tachycardia

Studies

• Diagnosis is based on clinical and laboratory findings, including thrombocytopenia, coagulation factor consumption, and fibrinolysis
• Serum labs   
  • coagulation factor consumption
    • elevated PT and aPTT
    • low fibrinogen
    • increased thrombin time
  • decreased factors V and VIII
  • thrombocytopenia
  • fibrinolysis
    • elevated D-dimer
• Peripheral blood smear with microangiopathic changes 
• schistocytes 

Differential

• Heparin-induced thrombocytopenia
  • key distinguishing factor
• history of recent heparin exposure and positive laboratory testing for heparin-platelet factor 4 antibodies

Treatment

• Medical
  • treat underlying disorder
  • supportive care
    • indication
      • all patients
    • modalities
      • fluids
      • platelet transfusions if < 10,000/μL
        • particularly for those who need urgent procedure
      • fresh frozen plasma
• consider heparin for any thrombosis

Complications

• Renal failure
• Liver injury
• Neurologic symptoms
  • thrombi and hypoperfusion
• Waterhouse-Friderichsen syndrome
  • adrenal insufficiency secondary to adrenal hemorrhage or infarct
  • commonly caused by Neisseria meningitidis
• Purpura fulminans
  • characterized by hemorrhagic skin necrosis, often at distal sites, due to thrombi
  • retiform purpura