Disseminated intravascular coagulation

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(Redirected from DIC)

Background

  • Systemic microvascular coagulation leading to organ dysfunction and depletion of clotting factors and platelets

Etiologies

Differential Diagnosis

Investigations

  • Thrombocytopenia is the most sensitive (Sn 98%)
  • D-dimer also sensitive, but not specific
  • Elevated INR/PTT (Sn 50-60%), but can be normal
  • Low fibrinogen is not very sensitive (Sn 28%), but serial measurement may be helpful
  • Blood film may show fragments

ISTH Diagnostic Scoring System

  • Only useful in the context of an underlying disorder known to be associated with overt DIC
  • Needs PT, platelet count, fibrinogen, and fibrin-related marker (e.g. D-dimer)
Marker Value Score
Platelet count >100
<100
<50
0
1
2
Elevated fibring marker (e.g. D-dimer, fibrin degradation products) no increase
moderate increase
strong increase
0
2
3
Prolonged PT <3 sec
>3 sec
>6 sec
0
1
2
Fibrinogen level >1 g/L
<1 g/L
0
1

Interpretation

  • ≥5 compatible with over DIC: repeat score daily
  • <5 suggestive for non-overt DIC: repeat in next 1-2 days

Management

  • Treat the underlying cause!

Transfusions

  • Only supplement blood products if they are actively bleeding, or to prepare them for an invasive procedure that may cause bleeding

Platelets

  • Platelets to target ≥50 if bleeding
  • Platelets not needed if not bleeding unless otherwise at risk
    • Weak evidence to target 10-20

Plasma and components

  • May be indicated in bleeding patients with PT or aPTT >1.5x normal or fibrinogen <1.5 g/L
  • FFP 15-30 ml/kg can correct the coagulopathy
  • PCC lacks Factor V and may worsen coagulopathy due to trace amounts of active factors
  • Fibrinogen 3 g should raise the plasma fibrinogen by about 1 g/L
    • Can be given as 4 units FFP, 2 units pooled cryoprecipitate, or 3 g fibrinogen concentrate

Anticoagulation

  • In cases of severe thrombosis, including arterial or venous thromboembolism, severe purpura fulminans associated with acral ischemia or vascular skin infarction, consider unfractionated heparin (UFH)
    • Target a PTT 1.5-2.5x normal
    • Monitor closely for bleeding
  • Other patients still need DVT prophylaxis with heparin or LMWH

Further Reading

  1. Wada H et al. Guidance for diagnosis and treatment of disseminated intravascular coagulation from harmonization of the recommendations from three guidelines. J Thromb Haemost. 2013;11:761–767.