A clinically significant incidence of bleeding in critically ill children receiving therapeutic doses of unfractionated heparin: a prospective cohort study.

Unfractionated heparin (UFH) is frequently prescribed for children for the prevention and treatment of thrombosis; however, its safety and efficacy have not been assessed. The aim of this single center, prospective cohort study was to determine the incidence of major bleeding and recurrent thrombosis in children receiving UFH. Major bleeding was defined a priori as: central nervous system or retroperitoneal bleeding, bleeding resulting in UFH being stopped or overt bleeding causing a drop in hemoglobin >20 g/dL in less than 24 h. Major bleeding events occurred in 9/38 children (24%, 95% CI 11-40%) and 2/38 (5%, 95% CI 0-18%) developed thrombosis. In conclusion, there is clinically significant bleeding in children receiving UFH.