Abstract
In polytrauma patients a thoracic trauma is one of the most critical injuries and an important trigger of post-traumatic inflammation. About 50% of patients with thoracic trauma are additionally affected by bone fractures. The risk for fracture malunion is considerably increased in such patients, the pathomechanisms being poorly understood. Thoracic trauma causes regional alveolar hypoxia and, subsequently, hypoxemia, which in turn triggers local and systemic inflammation. Therefore, we aimed to unravel the role of oxygen in impaired bone regeneration after thoracic trauma. We hypothesized that short-term breathing of 100% oxygen in the early post-traumatic phase ameliorates inflammation and improves bone regeneration. Mice underwent a femur osteotomy alone or combined with blunt chest trauma 100% oxygen was administered immediately after trauma for two separate 3 hour intervals. Arterial blood gas tensions, microcirculatory perfusion and oxygenation were assessed at 3, 9 and 24 hours after injury. Inflammatory cytokines and markers of oxidative/nitrosative stress were measured in plasma, lung and fracture hematoma. Bone healing was assessed on day 7, 14 and 21. Thoracic trauma induced pulmonary and systemic inflammation and impaired bone healing. Short-term exposure to 100% oxygen in the acute post-traumatic phase significantly attenuated systemic and local inflammatory responses and improved fracture healing without provoking toxic side effects, suggesting that hyperoxia could induce anti-inflammatory and pro-regenerative effects after severe injury. These results suggest that breathing of 100% oxygen in the acute post-traumatic phase might reduce the risk of poorly healing fractures in severely injured patients.
Highlights
More than 30% of polytrauma patients experience fractures of the extremities [1]
Using a mouse model of combined femur fracture and thoracic trauma we addressed the following questions: 1) Is impaired bone healing after thoracic trauma triggered by hypoxemia, and 2) Does intermitted exposure to 100% O2 in the acute post-traumatic phase ameliorate the inflammatory response and thereby improve fracture healing?
The present study addressed the role of O2 tension in the pathophysiology of disturbed bone healing after thoracic trauma
Summary
More than 30% of polytrauma patients experience fractures of the extremities [1]. In these patients bone healing is considerably disturbed, and the risk for malunion increases up to 50%PLOS ONE | DOI:10.1371/journal.pone.0131194 July 6, 2015Oxygen Improves Impaired Bone Healing after Trauma depending on trauma severity [2, 3]. The post-traumatic systemic inflammation is characterized by activation of immune cells, stimulation of protein cascades including the complement and coagulation systems, and a burst of pro- and antiinflammatory mediators [5] This inflammatory reaction can impair cell function even in remote tissues not directly affected by the initial trauma, and may lead to multiorgan dysfunction [6]. It is, evident that the over-activated immune response after severe trauma accounts for impaired bone regeneration, the cellular and molecular mechanisms are far from being well understood
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
