Effect of treatment delay on the effectiveness and safety of antifibrinolytics in acute severe hemorrhage

Antifibrinolytics can prevent death from severe bleeding, but new evidence from the London School of Hygiene & Tropical Medicine shows the agents are less effective if they are not administered at once. After searching results databases for relevant studies, researchers performed a meta-analysis of two large-scale clinical trials involving the use of tranexamic acid for bleeding induced by trauma or postpartum hemorrhage. Based on patient-level data for more than 40,100 participants, about 40% of the 3,558 reported deaths were due to bleeding; and approximately 63% of those bleeding deaths took place within 12 hours of onset. Immediate administration of tranexamic acid increased overall survival from bleeding by more than 70%, but treatment delays put patients in more danger of dying. The survival benefit declined by 10% for every 15 minutes that treatment was not delivered up to 3 hours, after which the benefit disappeared completely.