Disseminated Intravascular Coagulation

Introduction

• Disseminated Intravascular Coagulation (DIC) is a complex condition that always occurs secondary to an underlying disorder, such as sepsis, trauma, malignancy, or obstetric complications, as emphasized by the International Society on Thrombosis and Haemostasis (ISTH) 1, 2

Pathophysiology and Diagnosis

• DIC is not a primary disease but a pathophysiological process that accompanies various underlying conditions such as sepsis, trauma, malignancy, or obstetric complications 2
• Endothelial injury is an essential component in DIC pathophysiology, although current diagnostic criteria do not include biomarkers for vascular endothelial injury 2
• The International Society on Thrombosis and Haemostasis (ISTH) recommends screening for sepsis-induced coagulopathy (SIC) in patients with sepsis, which represents a compensated phase of DIC 2

Screening and Diagnostic Criteria

• SIC diagnostic criteria include platelet count, prothrombin time, and sequential organ failure assessment score 2
• The ISTH recommends using the overt DIC scoring system, which requires a score ≥5 points based on platelet count, prothrombin time, fibrinogen level, and fibrin-related markers to diagnose DIC, with a strength of evidence based on international consensus 1

• Normal laboratory ranges include:

  Parameter	Normal Range
  Platelet count	150-450 × 10^9/L
  Prothrombin time (PT/INR)	11-14 seconds / 0.9-1.1
  Fibrinogen	2-4 g/L
  D-dimer	< 0.5 mg/L

  3, 4

• DIC laboratory ranges include:

  Parameter	DIC Range
  Platelet count	< 50 × 10^9/L
  Prothrombin time (PT/INR)	> 14 seconds / > 1.1
  Fibrinogen	< 1.5 g/L
  D-dimer	> 0.5 mg/L

  3, 4

Management and Treatment

• For suspected DIC, perform immediate laboratory testing including platelet count, prothrombin time (PT), fibrinogen level, and D-dimer, then treat the underlying cause while providing blood product support based on bleeding status and laboratory parameters 4
• Maintain platelet count above 50 × 10⁹/L 4
• Administer 15-30 mL/kg of fresh frozen plasma (FFP) with careful clinical monitoring 4
• Consider prothrombin complex concentrates if volume overload is a concern 4
• If fibrinogen remains <1.5 g/L despite other measures, administer two pools of cryoprecipitate (when available) or fibrinogen concentrate 4
• Platelet transfusion is recommended for counts <50 × 10^9/L with active bleeding, and for counts <20-30 × 10^9/L in high-risk non-bleeding patients, as recommended by the ISTH 4
• Target higher platelet count (>100 × 10^9/L) for CNS injury or multiple trauma 5

Special Considerations

• In liver disease, bleeding is primarily related to portal hypertension rather than coagulopathy, as stated by the American Association for the Study of Liver Diseases 6
• The management of prolonged prothrombin time (PT) should be directed at the underlying cause rather than simply correcting the laboratory value, as PT prolongation alone does not necessarily predict bleeding risk, particularly in patients with cirrhosis who are in a 'rebalanced' hemostatic state 7
• Do not attempt to correct prolonged PT routinely before procedures, as evidence shows that prolonged PT does not predict bleeding in cirrhosis 7
• For active bleeding or before high-risk procedures, consider FFP (15 ml/kg) and maintain platelet count >50 × 10^9/L in actively bleeding patients 5
• Vitamin K (2.5-10 mg) should be administered for correction of anticoagulant-induced prolongation or significant bleeding risk, especially in cases of liver disease-related PT prolongation, as recommended by the American College of Gastroenterology 3, 8

Common Pitfalls

• Common pitfalls include overlooking the short lifespan of transfused products in active DIC, using antifibrinolytic agents without clear indication of hyperfibrinolytic DIC, and using recombinant Factor VIIa without evidence in DIC, as warned by the ISTH 4
• Delaying treatment of the underlying disease and misinterpreting normal coagulation screens, as a normal PT/aPTT does not exclude DIC, especially in subclinical forms, are also common pitfalls, as noted by the ISTH 4
• Relying solely on INR for non-warfarin patients can be misleading, as INR was designed specifically for warfarin monitoring, and ignoring clinical context can lead to misinterpretation of laboratory abnormalities 9