The Effect of Permissive Hypercapnia during Anesthesia on Postoperative Cognitive Dysfunction

术后认知功能障碍(POCD)是老年患者术后最常见的并发症之一，其会增加老年患者术后其他并发症发生率、延长住院时间、增加医疗费用和30天再入院率，影响患者预后。目前，药物与非药物手段预防术后认知功能障碍(POCD)的效果尚不确切，而允许性高碳酸血症作为一种肺保护性通气策略，对肺部、大脑及心脏均有一定程度的保护作用，其对术后认知功能的改善的作用也越来越被大家重视，本文将从允许性高碳酸血症对神经炎症反应、血脑屏障、脑灌注、脑氧代谢等多方面的作用进行综述，为允许性高碳酸血症对减少术后认知功能障碍的发生提供理论依据。Postoperative cognitive dysfunction (POCD) is one of the most common postoperative complications in elderly patients. It will increase the incidence of other postoperative complications in elderly patients, prolong hospitalization time, increase medical expenses and 30-day readmission rate, and affect the prognosis of patients. At present, the effect of drug and non-drug methods on the prevention of postoperative cognitive dysfunction (POCD) is not clear. While permissive hypercapnia, as a lung protective ventilation strategy, has a certain degree of protective effect on the lungs, brain and heart, and its effect on the improvement of cognitive function in the postoperative time has been paid more and more attention. This article reviews the effects of permissive hypercapnia on neuroinflammatory response, blood-brain barrier, cerebral perfusion, cerebral oxygen metabolism and other aspects, and provides a theoretical basis for permissive hypercapnia to reduce the occurrence of postoperative cognitive dysfunction.