Effect of Remote Ischemic Conditioning on Trauma Patients With Hemorrhagic Shock

Inclusion Criteria: * Age ≥16 years of age or estimated weight ≥50kgs if age is unknown; * Victim of blunt or penetrating trauma * Hemorrhagic shock defined as: * One or more episodes of systolic blood pressure ≤90mmHg at any time prior to enrollment into the study; * An identified source of blood loss (abdomen, chest, pelvis/retroperitoneum, extremities, external) or * Blood products (RBC, Platelets, Plasma, etc.) has been ordered to the trauma room. * Admitted to St. Michael's Hospital directly from the scene of injury within 3 hours of the injury * Application and completion of Remote Ischemic Conditioning (RIC) within 4 hours of the injury Exclusion Criteria: * Pregnancy * Non-hemorrhagic shock (i.e. tension pneumothorax, cardiac tamponade, spinal shock, etc.) * Major burns \> 20% total body surface area * Fracture of both lower extremities (i.e. traumatic amputation, fractures) * Absence of vital signs prior to admission, ongoing CPR, possibly dead on admission or not expected to survive beyond a few hours. * Injury in both legs (traumatic amputation, fractures, etc.) * Patients with a systolic blood pressure above 200mmHg * Patients treated with anticoagulants, antiplatelet therapy (Warfarin, Aspirin), steroids or with a known bleeding disorder or known abnormality of blood flow to the limb (if known) * Patients with osteoporosis or other bone disorders, peripheral nerve injury, abnormal nerve supply, peripheral neuropathy (if known) or preexisting traumatic injury to the limb. * Morbid obesity (largest cuff size won't fit) * If RIC is done clinically before research protocol begins.