Most diagnostic feature of DIC?

Ans. d (d - Dimer assay). (Ref. Harrison, Medicine, 18th ed. Ch.262)DIC (DISSEMINATED INTRAVASCULAR COAGULATION)# Damage to endothelial cells by endotoxins by gram-negative bacteria, thromboplastin production from damaged tissues, placenta; fat embolus activates extrinsic pathway, wide spread coagulation occurs due to circulating thrombin with consumption of platelet factors V, VIII, fibrinogen.# Bleeding or thrombosis can occur, although bleeding is common.# Microangiopathic hemolytic anemia occurs.# Hypofibrinogenemia, Raised PTT, ThrombocytopeniaThe quantitative plasma d-dimer ELISA rises in the presence of DVT or PE because of the breakdown of fibrin by plasmin. Elevation of d-dimer indicates endogenous although often clinically ineffective thrombolysis. The sensitivity of the d-dimer is >80% for DVT (including isolated calf DVT) and >95% for PE. The d-dimer is less sensitive for DVT than for PE because the DVT thrombus size is smaller. The d-dimer is a useful "rule out" test. More than 95% of patients with a normal (<500 ng/mL) d-dimer do not have PE. The d-dimer assay is not specific. Levels increase in patients with myocardial infarction, pneumonia, sepsis, cancer, postoperative state and pregnancy (2nd/3rd trimester).# Increased fibrinogen degradation products (D-dimer assay) is sensitive, but not specific.