Perioperative Neurocognitive Disorders
Perioperative neurocognitive disorders such as postoperative delirium are the most common postoperative complications in older surgical patients. In this chapter, first we provide a clinical overview of these disorders, and then we discuss the nomenclature and definitions of these perioperative neurocognitive disorders, including the requirement for a subjective cognitive complaint as well as an objectively measured cognitive deficit. We then discuss methods to assess for these disorders, the assumptions underlying these methods, and issues associated with the different thresholds used to define these disorders. Next, we discuss perioperative and intraoperative risk factors for these disorders, and practice recommendations to help minimize the risk of these disorders. We also discuss underlying mechanisms that may underlie these perioperative neurocognitive disorders, including those identified in both preclinical/animal and clinical/human studies, such as neurodegenerative disease-related mechanisms that may also play a role in these disorders. Finally, we conclude with a discussion of future research directions in the study of perioperative neurocognitive disorders, and ways that research on this topic may shed light on other brain disorders.
