Elderly and multimorbid patients are at high risk for developing unfavorable postoperative neurocognitive outcomes; however, well-adjusted and EEG-guided anesthesia may help titrate anesthesia and improve postoperative outcomes. Over the last decade, dexmedetomidine has been increasingly used as an adjunct in the perioperative setting. Its synergistic effect with propofol decreases the dose of propofol needed to induce and maintain general anesthesia. In this pilot study, we evaluate two highly standardized anesthetic regimens for their potential to prevent burst suppression and postoperative neurocognitive dysfunction in a high-risk population. Prospective, randomized clinical trial with non-blinded intervention. Operating room and post anesthesia care unit at Hospital Base San José, Osorno/Universidad Austral, Valdivia, Chile. 23 patients with scheduled non-neurologic, non-cardiac surgeries with age > 69 years and a planned intervention time > 60 min. Patients were randomly assigned to receive either a propofol-remifentanil based anesthesia or an anesthetic regimen with dexmedetomidine-propofol-remifentanil. All patients underwent a slow titrated induction, followed by a target controlled infusion (TCI) of propofol and remifentanil (n = 10) or propofol, remifentanil and continuous dexmedetomidine infusion (n = 13). We compared the perioperative EEG signatures, drug-induced changes, and neurocognitive outcomes between two anesthetic regimens in geriatric patients. We conducted a pre- and postoperative Montreal Cognitive Assessment (MoCa) test and measured the level of alertness postoperatively using a sedation agitation scale to assess neurocognitive status. During slow induction, maintenance, and emergence, burst suppression was not observed in either group; however, EEG signatures differed significantly between the two groups. In general, EEG activity in the propofol group was dominated by faster rhythms than in the dexmedetomidine group. Time to responsiveness was not significantly different between the two groups (p = 0.352). Finally, no significant differences were found in postoperative cognitive outcomes evaluated by the MoCa test nor sedation agitation scale up to one hour after extubation. This pilot study demonstrates that the two proposed anesthetic regimens can be safely used to slowly induce anesthesia and avoid EEG burst suppression patterns. Despite the patients being elderly and at high risk, we did not observe postoperative neurocognitive deficits. The reduced alpha power in the dexmedetomidine-treated group was not associated with adverse neurocognitive outcomes.

老年和多病患者发生不良术后神经认知结果的风险很高;然而，调整良好和脑电图引导的麻醉可能有助于滴定麻醉并改善术后结局。在过去的十年中，右美托咪定越来越多地用作围手术期的辅助治疗。它与异丙酚的协同作用减少了诱导和维持全身麻醉所需的异丙酚剂量。在这项初步研究中，我们评估了两种高度标准化的麻醉方案在预防高危人群爆发抑制和术后神经认知功能障碍方面的潜力。非盲干预的前瞻性随机临床试验。智利瓦尔迪维亚奥索尔诺/南方大学圣何塞医院基地的手术室和麻醉后监护室。23 名接受预定非神经、非心脏手术的患者，年龄 > 69 岁，计划干预时间 > 60 分钟。患者被随机分配接受基于异丙酚-瑞芬太尼的麻醉或右美托咪定-异丙酚-瑞芬太尼的麻醉方案。所有患者均接受缓慢滴定诱导，然后进行异丙酚和瑞芬太尼 （n = 10） 或异丙酚、瑞芬太尼和右美托咪定连续输注 （n = 13） 的目标对照输注 （TCI）。我们比较了老年患者两种麻醉方案之间的围手术期脑电图特征、药物诱导的变化和神经认知结局。我们进行了术前和术后蒙特利尔认知评估 （MoCa） 测试，并使用镇静激越量表测量术后警觉性水平，以评估神经认知状态。 在缓慢诱导、维持和出现期间，两组均未观察到突发抑制;然而，两组之间的脑电图特征差异显著。一般来说，异丙酚组的脑电图活动比右美托咪定组以更快的节律为主。两组之间的反应时间没有显着差异 （p = 0.352）。最后，通过 MoCa 测试和拔管后 1 小时内镇静激越量表评估的术后认知结果未发现显着差异。这项初步研究表明，两种提出的麻醉方案可以安全地用于缓慢诱导麻醉并避免脑电图爆发抑制模式。尽管患者年龄较大且处于高危状态，但我们没有观察到术后神经认知缺陷。右美托咪定治疗组的 α 功率降低与不良神经认知结局无关。