The Role of Brain-Bone Marrow-Gut Interaction Following Major Trauma

Severe Trauma Cohort Inclusion Criteria: 1. All adults (age ≥18). 2. Blunt trauma with an injury severity score \> 15 and a long bone or pelvic fracture requiring open reduction internal fixation or intramedullary fixation 3. Blunt trauma patients with shock, defined by either a systolic BP (SBP) \<90 mm Hg or base deficit (BD) ≥5 meq or lactate ≥ 2 mmol/L or active red blood cell or whole blood transfusion within 6h or arrival Exclusion Criteria: 1. Patients not expected to survive greater than 48 hours 2. Prisoners 3. Pregnancy 4. Previous bone marrow transplantation 5. Patients receiving chronic corticosteroids or immunosuppression therapies 6. Patients with End Stage Renal Disease 7. Patients with any pre-existing hematological disease 8. Surgery for repair of injury is greater than seven days after admission to the hospital for trauma 9. Burn injury greater than 20% TBSA Elective Hip Cohort Inclusion Criteria 1. All adults (age ≥55). 2. Patient undergoing elective hip repair for non-infectious reasons. 3. Ability to obtain Informed Consent prior to operation. Exclusion Criteria 1. Patients not expected to survive greater than 48 hours 2. Prisoners 3. Pregnancy 4. Previous bone marrow transplantation 5. Patients receiving chronic corticosteroids or immunosuppression therapies 6. Patients with End Stage Renal Disease 7. Patients with any pre-existing hematological disease