Role of lung contusions on posttraumatic inflammatory response and organ dysfunction in traumatized patients

Multiple trauma is often accompanied by lung contusion leading to secondary pulmonary inflammation and organ dysfunction. The particular role of lung contusions on the systemic inflammatory response remains unclear. Therefore, the aim of the present study was to compare the degree of lung contusion with markers of inflammation and multiple organ failure (MOF) in trauma patients.

According to the Injury Severity Score (ISS), 45 patients were assigned to a low (< 25 points) and a high ISS group (> 25 points), respectively. Both groups were subdivided into minor and major lung injury groups as defined by computed tomography (CT) scan. Plasma levels of interleukin 6 (IL-6), interleukin 8 (IL-8), tumor necrosis factor (TNF) receptors, C-reactive protein (CRP), and polymorphonuclear (PMN) elastase were assessed, as well as the Murray lung score (MLS) and the MOF score.

Patients with low ISS present moderate activation of inflammation which is not influenced by the degree of lung contusion. In contrast, patients with a high ISS develop significant posttraumatic inflammation and MOF. Patients with high ISS and severe lung contusions present significantly higher MLS and MOF scores. Interestingly, patients of the high ISS group without severe lung contusions develop a similar degree of MLS and MOF only after 5 days following the traumatic insult. However, the initial plasma levels of IL-6 and IL-8 differ significantly in this group.

Our data show that severe lung contusions contributes to an immediate onset of posttraumatic inflammation in severely traumatized patients, resulting in MOF, while in severely injured patients without lung contusion, this development requires up to 5 days.