What are the key laboratory findings in disseminated intravascular coagulation?

What are the key laboratory findings in disseminated intravascular coagulation?

• A. Prolonged PT and aPTT, elevated D-dimer, thrombocytopenia, and decreased fibrinogen
• B. Shortened PT and aPTT, normal D-dimer, thrombocytosis
• C. Normal coagulation tests
• D. Elevated fibrinogen with normal platelets

Answer: (A)

Disseminated intravascular coagulation causes widespread clotting that consumes clotting factors and platelets, followed by a tendency to bleeding as those resources are depleted. The lab picture reflects this consumption: the clotting times (PT and aPTT) become prolonged because factors are used up; platelet count drops from ongoing consumption; fibrinogen levels fall as it’s converted to fibrin in many clots; and fibrin degradation products, including D-dimer, rise as clots are broken down. This combination—prolonged PT and aPTT, low platelets, low fibrinogen, and elevated D-dimer—best fits DIC. Patterns with shortened coagulation times, normal tests, or high fibrinogen with normal platelets do not match the consumption coagulopathy seen in DIC.

Disseminated intravascular coagulation causes widespread clotting that consumes clotting factors and platelets, followed by a tendency to bleeding as those resources are depleted. The lab picture reflects this consumption: the clotting times (PT and aPTT) become prolonged because factors are used up; platelet count drops from ongoing consumption; fibrinogen levels fall as it’s converted to fibrin in many clots; and fibrin degradation products, including D-dimer, rise as clots are broken down. This combination—prolonged PT and aPTT, low platelets, low fibrinogen, and elevated D-dimer—best fits DIC. Patterns with shortened coagulation times, normal tests, or high fibrinogen with normal platelets do not match the consumption coagulopathy seen in DIC.