A new multiple trauma model of the mouse

Abstract

BackgroundBlunt trauma is the most frequent mechanism of injury in multiple trauma, commonly resulting from road traffic collisions or falls. Two of the most frequent injuries in patients with multiple trauma are chest trauma and extremity fracture. Several trauma mouse models combine chest trauma and head injury, but no trauma mouse model to date includes the combination of long bone fractures and chest trauma. Outcome is essentially determined by the combination of these injuries. In this study, we attempted to establish a reproducible novel multiple trauma model in mice that combines blunt trauma, major injuries and simple practicability.MethodsNinety-six male C57BL/6 N mice (n = 8/group) were subjected to trauma for isolated femur fracture and a combination of femur fracture and chest injury. Serum samples of mice were obtained by heart puncture at defined time points of 0 h (hour), 6 h, 12 h, 24 h, 3 d (days), and 7 d.ResultsA tendency toward reduced weight and temperature was observed at 24 h after chest trauma and femur fracture. Blood analyses revealed a decrease in hemoglobin during the first 24 h after trauma. Some animals were killed by heart puncture immediately after chest contusion; these animals showed the most severe lung contusion and hemorrhage. The extent of structural lung injury varied in different mice but was evident in all animals. Representative H&E-stained (Haematoxylin and Eosin-stained) paraffin lung sections of mice with multiple trauma revealed hemorrhage and an inflammatory immune response. Plasma samples of mice with chest trauma and femur fracture showed an up-regulation of IL-1β (Interleukin-1β), IL-6, IL-10, IL-12p70 and TNF-α (Tumor necrosis factor- α) compared with the control group. Mice with femur fracture and chest trauma showed a significant up-regulation of IL-6 compared to group with isolated femur fracture.ConclusionsThe multiple trauma mouse model comprising chest trauma and femur fracture enables many analogies to clinical cases of multiple trauma in humans and demonstrates associated characteristic clinical and pathophysiological changes. This model is easy to perform, is economical and can be used for further research examining specific immunological questions.

Traumatic injury pattern is of equal relevance as injury severity for experimental (poly)trauma modeling

“…In our previous findings, a CT scan of TxT group has shown intrathoracic bleeding and hemopneumothorax without rib fractures, while the histological analyses reflected hemothorax and lung contusion in this model 12 . Here, cardiac rupture, pericardial laceration, laceration to a coronary artery followed by hemothorax or complex lung contusion caused the mortality after chest trauma.…”

“…Among several available femur fracture models, here, external fixation model was chosen. Fracture can be fixed with intramedullary Kirschner wires or syringe needles as well, imitating human intramedullary nailing without applying locking screws 12,58 . However, single intramedullary Kirschner wires or syringe cannot provide rotational and axial stability.…”

“…Blunt thoracic trauma was induced as previously described 12 . In short, mice were fixed in a supine position after induction of anesthesia.…”

Different experimental multiple trauma models induce comparable inflammation and organ injury

“…The most common in vivo trauma models combine mainly two insults to better imitate the human conditions 9,[21][22][23][24][25][26] . However, considering the definition of polytrauma according to the ISS or the new Berlin Group allocation and experimental model.…”

Experimental induction of blunt chest trauma in mice: A modified approach with evaluation in dummies and cadavers

“…A previous study reported the physiological and immunological characterization of a long-term model of blunt chest trauma in mice using a blast wave generator (3). Another approach for inducing blunt chest trauma is dropping a weight from a defined height, which has been used in multiple rat and murine trauma models (4)(5)(6).…”