The goal of this study will be to determine if a lower than normal blood pressure during surgery for bleeding in the abdomen or chest will result in decreased bleeding and decreased chance of death.

For the proposed study, all trauma patients undergoing laparotomy or thoracotomy for trauma that had a systolic blood pressure < 90 mmHg prior to going to the operating room will be randomized to one of two groups. The randomization will take place at the operating room door. The first group will have a target minimum mean arterial pressure of 50 mm Hg (LMAP) and the second group will have a target minimum mean arterial pressure of 65 mmHg (HMAP). Before the operating room and in all other aspects of their care the patients will be treated as per standard of care. Patients will then be followed to determine if there is a difference in 30 day survival between the two groups. Secondary outcome measures will be Sequential Organ Failure Assessment (SOFA) score, APACHE II, ARDS, ICU length of stay, myocardial ischemia, stroke, acidosis, coagulopathy by conventional labs and thromboelastogram, estimated blood loss, transfusion requirements, Glasgow Outcome Score, the presence of leukocyte apoptosis, the serum level of the pro-inflammatory cytokines, IL-6 and G-CSF, and the rate of infectious complications (VAP, UTI, Wound infections). Blood samples (20 ml each) will be taken at three time points: prior to randomization, immediately after the end of resuscitation protocol, and 24 hrs after randomization. Blood will be examined for the presence of leukocyte apoptosis and levels of IL-6 and G-CSF.

Inclusion Criteria:

• All adult patients seen in the Ben Taub emergency center that have suffered a trauma, have a systolic blood pressure less than 90mm Hg, and are going to the operating room for a laparotomy or thoracotomy

Exclusion Criteria:

• Known or suspected head injury
• Age > 45 years old, <= 12 years old
• Incarcerated individuals
• Pregnant women
• Patients with an advanced directive that refuse resuscitation
• Patients with "opt-out" bracelets that signify their refusal of participation in the project