CAlcium and VAsopressin Following Injury Early Resuscitation (CAVALIER) Trial

Inclusion Criteria: Prehospital Phase: Injured patients at risk of hemorrhagic shock being transported from scene or referral hospital to a participating CAVALIER trial site who meet the following criteria: 1A. Systolic blood pressure ≤ 90mmHg and tachycardia (HR ≥ 108) at scene, at outside hospital, or during anticipated transport to a participating CAVALIER trial site OR 1B. Systolic blood pressure ≤ 70mmHg at scene, at outside hospital, or during anticipated transport to a participating CAVALIER trial site Early In-Hospital Phase: Injured patients at a participating CAVALIER trial site at risk of hemorrhagic shock who meet the following criteria: 1A. Systolic blood pressure ≤ 90mmHg and tachycardia (HR ≥ 108) at scene, at outside hospital, during transport, or in emergency department of a participating CAVALIER trial site OR 1B. Systolic blood pressure ≤ 70mmHg at scene, at outside hospital, during transport, or in emergency department of a participating CAVALIER trial site AND 2.Blood/blood component transfusion initiated in prehospital setting or deemed clinically indicated within 60 minutes of arrival at the enrolling trauma center AND 3. Clinical team deems Operating Room for major hemorrhage control procedure (e.g., laparotomy, thoracotomy, vascular exploration or extremity amputation) indicated within 60 minutes of arrival at the enrolling trauma center AND 4\. Anticipated admission to intensive care unit (ICU) Exclusion Criteria: Prehospital Phase 1. Wearing NO CAVALIER opt-out bracelet 2. Age \> 90 or \< 18 years of age 3. Isolated fall from standing injury mechanism 4. Known prisoner 5. Known pregnancy 6. Traumatic arrest with \> 5 minutes of CPR without return of vital signs 7. Brain matter exposed or penetrating brain injury 8. Isolated drowning or hanging victims 9. Objection to study voiced by subject or family member at the scene or at the trauma center 10. Inability to obtain IV/IO access Early In-Hospital Phase: 1. Wearing NO CAVALIER opt-out bracelet 2. Age \> 90 or \< 18 years of age 3. Isolated fall from standing injury mechanism 4. Known prisoner 5. Known pregnancy 6. Traumatic arrest with \> 5 minutes of CPR without return of vital signs 7. Brain matter exposed or penetrating brain injury 8. Isolated drowning or hanging victims 9. Objection to study voiced by subject or family member at the scene or at the trauma center 10. Inability to obtain IV access