A Comprehensive Review of the Depth of Anesthesia and Its Impact on Postoperative Delirium Development

Postoperative delirium is a frequent surgical patient complication, particularly the elderly, which is always associated with more risk of extended hospital stays, heightened healthcare expenses, and elevated mortality rates. Although numerous factors contribute to postoperative delirium, recent research has emphasized the potential significance of anesthesia depth during surgery. In addition, while certain mechanisms behind the disease are still not clear, the impact of depth of anesthesia on the incidence of postoperative delirium is contradictory. This article first explores the pathophysiology, recognition and diagnosis of postoperative delirium, analyzing correlative risk factors of the cognitive disorder. As one of the conventional technologies monitoring the depth of anesthesia, the measurement method and principle of bispectrality analysis of electroencephalogram are listed. Ultimately, the link between anesthesia depth and POD incidence is examined, exploring the underlying causes. The analytical approach employed in this article may serve as a reference for investigating similar risk factors or cognitive disorders. Also, suggestions on clinical practice could be offered by the result of the study. However, whether deeper anesthesia would contribute to higher risk of postoperative delirium is still unclear. In addition, the certain mechanism of postoperative delirium could be focused in further studies.