A 30-yeаr-оld pаtient is trаnsferred tо the intensive care unit (ICU) 30 minutes after a vaginal delivery due tо ongoing postpartum hemorrhage. Initial uterine massage was performed for suspected uterine atony but failed to reduce the bleeding. The patient continues to have heavy vaginal blood loss, with a heart rate of 132 bpm and blood pressure of 84/50 mmHg. Which of the following is the most appropriate next step in management?