The evaluation of the effect of mannitol and 3% hypertonic saline treatment on optic nerve sheath diameter by ultrasound in patients with brain edema in the intensive care unit

Brain edema is a pathological condition characterized by the accumulation of intracellular and/or extracellular fluid in the intracranial space. It can increase intracranial pressure (ICP), reduce cerebral perfusion pressure (CPP), and impair cerebral oxygenation. Additionally, the mass effect caused by brain edema can lead to fatal herniation. Therefore, the diagnosis of brain edema, monitoring of elevated ICP, and treatment approaches are of critical importance. In this study, we aimed to evaluate the effectiveness of treatment by comparing optic nerve sheath diameter (ONSD) measurements in patients who received 20% mannitol and 3% hypertonic saline (HTS) due to brain edema. Following the approval of the ethics committee, 50 patients who had been admitted to the Anesthesia and Intensive Care Unit of Fırat University Medical Faculty Hospital with a diagnosis of cerebral edema and had received 20% mannitol or 3% HTS treatment were included in our study. The patients' admission diagnoses, demographic data, history of comorbidities, medications used, Glasgow Coma Scale (GCS) scores, hemodynamic parameters, complete blood count, biochemical parameters, blood gas results, need for mechanical ventilation, positive end-expiratory pressure (PEEP) and PEEP-related values, and oxygen saturation (SpO2) measurements were recorded from patient files at the time of admission to the intensive care unit, at the 30th minute, 1st hour, 1st day, 3rd day, and 5th day. Although a post-treatment reduction in ONSD measurements was observed in both groups, no statistically significant difference was found between the two groups at any time point. However, serum sodium and osmolarity values in the HTS group were higher than in the mannitol group on days 1, 3, and 5. In conclusion, cerebral edema is a serious clinical condition that can develop due to various etiological factors and may require intensive care in some patients. Minimizing mortality and morbidity in this patient population is possible through effective and timely critical care management. The choice of osmotherapy agents used in the treatment of cerebral edema should be based on the patient's hemodynamic status, fluid-electrolyte balance, and cardiovascular or renal function. This individualized treatment approach plays a vital role in managing complications associated with cerebral edema and may contribute to improved clinical outcomes. Keywords: Cerebral Edema, Increased Intracranial Pressure, Mannitol, Hypertonic Saline, Optic Nerve Sheath Diameter