Hypernatremia for the Prevention and Treatment of Cerebral Edema in Traumatic Brain Injury

Cerebral edema is seen heterogenous group of neurological disease states that mainly fall under the categories of metabolic, infectious, neoplasia, cerebrovascular, and traumatic brain injury disease states. Regardless of the driving force, cerebral edema is defined as the accumulation of fluid in the brain's intracellular and extracellular spaces. This occurs secondary to alterations in the complex interplay between four distinct fluid compartments within the cranium. In any human cranium; fluid is contained in the blood, the cerebrospinal fluid, interstitial fluid of the brain parenchyma, and the intracellular fluid of the neurons and glia. Fluid movement occurs normally between these compartments and depends on specific concentrations of solutes (such as sodium) and water. In brain-injured states, the normal regulation of this process is disturbed and cerebral edema can develop. Cerebral edema leads to increased intracranial pressure and mortality secondary to brain tissue compression, given the confines of the fixed-volume cranium. Additionally, secondary neuronal dysfunction or death can occur at the cellular level secondary to the disruption of ion gradients that control metabolism and function. While studies utilizing bolus dosing of hyperosmolar therapy to target signs or symptoms of increased intracranial pressure secondary to cerebral edema are numerous, there is a paucity of studies relating to continuous infusion of hyperosmolar therapy for targeted sustained hypernatremia for the prevention and treatment of cerebral edema. The investigators hypothesize that induced, sustained hypernatremia following traumatic brain injury will decrease the rate of cerebral edema formation and improve patient outcomes.