A 32-year-old man is brought to the emergency department following a motor vehicle collision. He was the driver and was not wearing a seatbelt. On arrival, his blood pressure is 88/56 mmHg, heart rate 128 bpm, respiratory rate 24/min, and he is anxious and restless. Examination reveals a distended abdomen with bruising over the left flank. Two large-bore IV lines are established. After 2 L of crystalloid infusion over 10 minutes, his BP remains 90/58 mmHg and HR is 126 bpm. His hemoglobin is 9.2 g/dL (baseline unknown). What is the most appropriate next step in management?

## Clinical Context This patient presents with **Class III hemorrhagic shock** (BP 88/56, HR 128, altered mental status) following blunt abdominal trauma with signs of intra-abdominal bleeding (distended abdomen, flank bruising). Critically, he is a **non-responder** to initial crystalloid resuscitation—his vital signs have not improved after 2 L of fluid. ## Why Massive Transfusion Protocol (MTP) is Correct **Key Point:** Non-responders to initial crystalloid in hemorrhagic shock require immediate blood product resuscitation and definitive hemorrhage control (surgery). **High-Yield:** The **ATLS guideline** defines a non-responder as a patient who does not improve or deteriorates despite 2 L of crystalloid. This mandates: 1. Activation of **massive transfusion protocol** (1:1:1 PRBC:FFP:platelets) to prevent coagulopathy 2. **Immediate transfer to OR** for exploratory laparotomy (presumed splenic or mesenteric injury given flank trauma and abdominal distension) 3. Permissive hypotension (target SBP 90 mmHg) until bleeding is controlled—avoid over-resuscitation **Clinical Pearl:** In a non-responder with blunt abdominal trauma and hemodynamic instability, **do not delay for imaging**. The diagnosis is presumed intra-abdominal hemorrhage requiring operative intervention. **Mnemonic: STOP** (Shock, Transfuse, Operate, Prevent coagulopathy)—the sequence for non-responders. ## Why CT is Inappropriate Here CT imaging is appropriate for **stable or transiently responding** patients. A non-responder is **unstable** and requires the OR, not the CT scanner. ## Why Vasopressors Alone Are Wrong Vasopressors without blood products and surgical hemostasis will cause end-organ hypoperfusion and death. They are a **temporizing measure only**, never a substitute for transfusion and operative control.