Stepwise management of primary postpartum hemorrhage — uterotonics, tamponade, and surgical options

A G3P3 patient has estimated blood loss of 1200 mL after vaginal delivery with uterine atony. After IV oxytocin 20 units, uterus remains boggy. What is the stepwise approach: misoprostol, carboprost, tranexamic acid, bimanual compression, Bakri balloon, B-Lynch suture, uterine artery ligation, and finally hysterectomy? What are contraindications to carboprost (15-methyl PGF2a)? When do we activate massive transfusion protocol?