The effect of patient position on cerebral regional oxygen saturation in intracranial surgery

Our study aims to evaluate the effects of the positions applied to patients undergoing intracranial surgery at the Department of Anesthesiology and Reanimation of Trakya University Medical Faculty on cerebral oxygenation and the superiority of the patient positions used over each other, and to reveal prognostic factors in providing oxygenation. For this purpose, 105 patients aged 25-75 in the ASA I-II-III risk group were included in our study. In intracranial surgery, patients were divided into 4 groups according to the location of the mass, the surgeon's field of vision and the positions applied; supine, right lateral, left lateral and prone positions. Demographic characteristics of the patients, the name of the intracranial mass surgery and the surgical procedure area were recorded during the preoperative visit. The patients' baseline, pre-intubation, post-intubation, pin insertion, surgical position 0 min, surgical position 5 min, skin incision, craniotomy initiation, dura opening, bleeding control, skin closure, pin removal periods, and also intraoperatively, the first 20 min after positioning, at 5-min intervals, then at 10-min intervals until the 60th minute, then at 30-min intervals until the 150th minute, and finally at postoperative time, systolic and diyastolic blood pressure, heart rate, peripheral oxygen saturation, end tidal carbon dioxide, and NIRS values were recorded. In our clinic, two electrodes were placed on the frontal region for NIRS measurements (Masimo MOC-9 module) and recorded. Preoperative and postoperative blood gas values of all patients were recorded. Postoperative delirium status of the patients was examined. After the prone position, rSO2 increased compared to the right lateral, left lateral and supine positions, while no positional difference was observed in maintaining hemodynamics. The fact that the subsendral delirium seen in the early postoperative period in the lateral position was similar in all positions on the 2nd day should be taken into consideration when deciding on the appropriate position of patients in long-term surgeries. In conclusion, it can be said that intraoperative cerebral oxygenation monitoring may reduce mortality and morbidity by providing an early indicator of potential postoperative neurological and neurocognitive function deficits in patients undergoing intracranial surgery.