Experimental Models Combining TBI, Hemorrhagic Shock, and Hypoxemia.

Animal models of traumatic brain injury (TBI) provide important tools for studying the pathobiology of brain trauma and for evaluating therapeutic or diagnostic targets. Incorporation of additional insults such as hemorrhagic shock (HS) and/or hypoxemia (HX) into these models more closely recreates clinical scenarios as TBI often occurs in conjunction with these systemic insults (i.e., polytrauma). We have developed a rat model of polytrauma that combines penetrating TBI, HS and HX. Following brain trauma, HX was induced by reducing the inspired oxygen while HS was induced by withdrawing blood to lower the mean arterial pressure. The physiological, histological, and behavioral aspects of this animal model have been characterized and have demonstrated exacerbating effects of systemic insults on penetrating TBI. As such, this model may facilitate the use of simultaneous assessments of multiple mechanisms and provide a platform for testing novel diagnostic and therapeutic targets.