Massive Hemorrhage Protocol

Massive hemorrhage is a time-critical failure of circulating volume and hemostasis. The response must run on two tracks at once: the team replaces blood components and corrects the physiologic conditions that prevent clot formation, while surgery, interventional radiology, endoscopy, obstetric intervention, or another definitive service controls the bleeding source. In Ontario's 2025 update, Massive Hemorrhage Protocol (MHP) replaces the narrower term Massive Transfusion Protocol (MTP), reflecting this broader response. Do not wait for the patient to receive 10 red blood cell units before activating the protocol; that number defines the scale of massive hemorrhage retrospectively. Activate according to the patient's current bleeding, perfusion, predicted transfusion requirement, and local hospital policy.