Incidence of post-traumatic pneumonia in poly-traumatized patients: identifying the role of traumatic brain injury and chest trauma.

Traumatic brain injury (TBI) and chest trauma are common injuries in severely injured patients. Both entities are well known to be associated with severe post-traumatic complications, including pneumonia, a common complication with a significant impact on the further clinical course. However, the relevance of TBI, chest trauma and particularly their combination as risk factors for the development of pneumonia and its impact on outcomes are not fully elucidated. A retrospective analysis of poly-traumatized patients treated between 2010 and 2015 at a level I trauma centre was performed. Inclusion criteria were: Injury Severity Score ≥ 16 and age ≥ 18 years. TBI and chest trauma were classified according to the Abbreviated Injury Scale. Complications (i.e. acute respiratory distress syndrome (ARDS), multi-organ dysfunction syndrome (MODS) and pneumonia) were documented by a review of the medical records. The primary outcome parameter was in-hospital mortality. Over the clinical course, 19.9% of all patients developed pneumonia, and in-hospital mortality was 25.3%. Pneumonia (OR 5.142, p = 0.001) represented the strongest independent predictor of in-hospital mortality, followed by the combination of chest injury and TBI (OR 3.784, p = 0.008) and TBI (OR 3.028, p = 0.010). Chest injury alone, the combination of chest injury and TBI, and duration of ventilation were independent predictors of pneumonia [resp. OR 4.711 (p = 0.004), OR 4.193 (p = 0.004), OR 1.002 (p < 0.001)]. Chest trauma alone and especially its combination with TBI represent high-risk injury patterns for the development of pneumonia, which forms the strongest predictor of mortality in poly-traumatized patients.