Postoperative Cognitive Dysfunction after Coronary Artery Bypass Grafting

Abstract Postoperative cognitive dysfunction is a common complication following cardiac surgery. The incidence of cognitive dysfunction is more pronounced in patients receiving a cardiac operation than in those undergoing a non-cardiac operation. Clinical observations demonstrated that pulsatile flow was superior to nonpulsatile flow, and membrane oxygenator was superior to bubble oxygenator in terms of postoperative cognitive status. Nevertheless, cognitive assessments in patients receiving an on-pump and off-pump coronary artery bypass surgery have yielded inconsistent results. The exact mechanisms of postoperative cognitive dysfunction following coronary artery bypass grafting remain uncertain. The dual effects, neuroprotective and neurotoxic, of anesthetics should be thoroughly investigated. The diagnosis should be based on a comprehensive cognitive evaluation with neuropsychiatric tests, cerebral biomarker inspections, and electroencephalographic examination. The management strategies for cognitive dysfunction can be preventive or therapeutic. The preventive strategies of modifying surgical facilities and techniques can be effective for preventing the development of postoperative cognitive dysfunction. Investigational therapies may offer novel strategies of treatments. Anesthetic preconditioning might be helpful for the improvement of this dysfunction.

摘要：术后认知功能障碍（postoperative cognitive dysfunction）是心脏手术后常见的并发症。接受心脏手术的患者发生认知功能障碍的风险显著高于非心脏手术患者。临床观察表明，就术后认知状态而言，搏动性血流灌注方案优于非搏动性血流灌注方案，膜式氧合器（membrane oxygenator）优于鼓泡式氧合器。然而，针对体外循环与非体外循环冠状动脉旁路移植术（coronary artery bypass surgery）患者的认知评估结果并不一致。冠状动脉旁路移植术（coronary artery bypass grafting）后认知功能障碍的确切发病机制仍未明确。麻醉药物兼具神经保护与神经毒性的双重效应，该效应亟待开展深入研究。术后认知功能障碍的诊断需基于综合认知评估，涵盖神经精神测试、脑部生物标志物检测及脑电图（electroencephalographic examination）检查。认知功能障碍的管理策略可分为预防与治疗两大类。优化手术设施与技术的预防性策略，可有效降低术后认知功能障碍的发生风险。探索性疗法有望为该病症提供全新的治疗思路。麻醉预处理或许有助于改善此类术后认知功能障碍。