SIRS, which can mimic PN, is common in trauma patients. These entities can be distinguished by bronchoscopy with BAL. Basing antibiotic therapy solely on quantitative BAL cultures is efficacious in trauma patients.

Gastric injuries are equivalent to colon wounds in their contribution to IAA. Contamination from either organ without associated injury is minimally associated with IAA, but injury to both appears synergistic. The immunosuppressive effects of age and hemorrhage, in addition to significant associated injury, enhance the development of IAA.

Posttraumatic mediastinal abscess is an uncommon complication of blunt trauma in general and sternal fracture in particular. It can be recognized by the development of sternal instability. Risk factors include the presence of hematoma, intravenous drug abuse, and source of staphylococcal infection. Treatment with early debridement and irrigation can avoid the need for muscle flap closure.