Fluid therapy for acute brain injury

Background. The primary goals of fluid therapy in acute brain injury (ABI) are recovery of circulating blood volume, maintaining central hemodynamics, cerebral blood flow, oxygenation, and water-electrolyte balance, as well as prevention and treatment of intracranial hypertension and cerebral edema. Objective. To evaluate clinical approaches to fluid therapy in ABI taking into account the mechanisms regulating cerebral fluid distribution. Material and methods. We reviewed the PubMed and eLibrary databases between 2000 and 2024 using the following keywords: acute brain injury, fluid therapy, crystalloids, and hyperosmolar therapy. This review explores pathophysiological basis of fluid therapy in ABI and modern infusion solutions. Damage to blood-brain barrier (BBB) is associated with increased intracranial pressure (ICP) and cerebral edema. In clinical practice, osmolarity of intravenous solution should be considered before infusion. In early phase of ABI treatment, 0.9% NaCl is preferable in most cases as its osmolarity is slightly higher than one of blood plasma. Colloids, glucose-containing hypotonic solutions, balanced crystalloids, and albumin (regardless of concentration) are not recommended at this stage, particularly in the absence of hypernatremia or hyperchloremia. In delayed phase, fluid therapy should be personalized rather than standardized, while neuromonitoring and multimodal central hemodynamic monitoring are essential. Conclusion. When choosing fluid therapy, one should consider etiology and phase of brain injury, cerebral or extracerebral complications, baseline water-electrolyte balance and its dynamics, plasma osmolarity, and tonicity of solutions.