Fluid therapy and traumatic brain injury: A narrative review.

Traumatic brain injury (TBI) is an important health and social problem. The mechanism of damage of this entity could be divided into two phases: (1) a primary acute injury because of the traumatic event; and (2) a secondary injury due to the hypotension and hypoxia generated by the previous lesion, which leads to ischemia and necrosis of neural cells. Cerebral edema is one of the most important prognosis markers observed in TBI. In the early stages of TBI, the cerebrospinal fluid compensates the cerebral edema. However, if edema increases, this mechanism fails, increasing intracranial pressure. To avoid this chain effect, several treatments are applied in the clinical practice, including elevation of the head of the bed, maintenance of normothermia, pain and sedation drugs, mechanical ventilation, neuromuscular blockade, controlled hyperventilation, and fluid therapy (FT). The goal of FT is to improve the circulatory system to avoid the lack of oxygen to organs. Therefore, rapid and early infusion of large volumes of crystalloids is performed in clinical practice to restore blood volume and blood pressure. Despite the relevance of FT in the early management of TBI, there are few clinical trials regarding which solution is better to apply. The aim of this study is to provide a narrative review about the role of the different types of FT used in the daily clinical practice on the management of TBI. To achieve this objective, a physiopathological approach to this entity will be also performed, summarizing why the different types of FT are used.