DIAGNOSING DISSEMINATED INTRAVASCULAR COAGULATION IN ACUTE INFECTION : CAN WE DO WITHOUT FDP & D-DIMER

Alterations in coagulation profile viz. platelet count, prothrombin time (PT), partial thromboplastin time with kaolin (PTTK), thrombin time (TT) and fibrinogen were studied in 96 patients (73 males and 23 females) of acute infections. Fibrin/fibrinogen degradation products (FDP) level >25µg fibrinogen equivalent unit (FEU)/ml along-with D-dimer >1.0µg FEU/ml was considered criteria for diagnosis of disseminated intravascular coagulation (DIC). Normal values were established using plasma from 12 healthy voluntary blood donors. Out of these 96 patients, 15 had infection with Gram positive bacteria, 23 with Gram negative bacteria and 38 with Dengue. In 20 patients, nature of infection was not defined. Mean platelet count per cubic millimetre was 2.14 lac in Gram positive infection and 1.74 lac in Gram negative infection (p=0.07). There was no significant difference in other coagulation parameters in Gram positive and Gram negative infection. Platelet counts were low in 71% of Dengue patients but there was no significant alteration in PT, PTTK and TT. None of the Dengue patients had hypofibrinogenemia or DIC though hyperfibrinogenemia was present in 21% of Dengue patients. 20 patients had features of septicemia (Gram +ve 7, Gram -ve 8, undefined 5); 10 had concomitant DIC. DIC was present in additional 4 patients of acute infection without septicemia. PTTK was raised in 60% of the septicemia patients. 20 out of 82 non-DIC acute infection patients had subnormal PTTK. Commonest alteration in 14 DIC patients was raised PTTK with a sensitivity of 78.6% and specificity of 81.7%. Low fibrinogen levels though specific for DIC, were present in only 21.4% of the DIC patients. Combinations of PTTK >38 sec with PT >15 sec or platelet count < 1.5 lac/mmm(3) were good screening tests for DIC and detected 11 and 10 patients out of 14 with three and two false positives respectively.