In hemophilia A, the factor VIII level should be raised transiently to About 30% of normal to prevent bleeding after dental extraction or to abort an incipient joint hemorrhage 50% of normal if severe joint or IM bleeding is already evident 100% of normal before major surgery or if bleeding is intracranial, intracardiac, or otherwise life threatening Repeated infusions at 50% of the initial calculated dose should then be given every 8 to 12 hours to keep trough levels > 50% for 7 to 10 days after major surgery or life-threatening hemorrhage.