Patient who have major traumatic injury are at risk to develop postoperative inflammatory complications such as pneumonia and lung trouble called adult respiratory distress syndrome (ARDS). This study will draw blood from trauma patients are several time points after their injury to see if we can predict who is at greatest risk for developing pneumonia or ARDS based upon the results of these immune lab tests. We are particularly interested to see if this will be useful in obese patients who have a greater risk of these post trauma complications