Difficulties in Understanding Postoperative Cognitive Dysfunction

Abstract

Aim of review: Firstly brought up by Bedford in 1955, postoperative cognitive dysfunction (POCD) has been given increasing attention due to the increase of the elderly population. Although many researches have been conducted on POCD, the understanding of this clinical syndrome is still limited. There are currently many disputes regarding almost every aspects of POCD, even the term itself has not been included in the MeSH Database. This review aims to discuss the major disputes about POCD that hinder research consistency and provide possible perspectives for future research.Method: Recent articles and literatures about POCD were searched and reviewed. First, basic knowledge of POCD, including characteristics and incidence, risk factors, mechanisms, prevention and intervention are introduced. Second, the major obstacles of investigating POCD are discussed. Then two major problems are proposed: 1) Does the POCD in patients really start postoperatively? 2) Is POCD only related to old age? Finally, the never-ending argument regarding the role of anesthesia on POCD is discussed.Recent findings: Recent researches regarding POCD focused on the surgery-related neuroinflammation mechanism, and efforts have been made to find some biomarkers of POCD. In terms of POCD, there are many fundamental concepts and in urgent need of consensus. First, unifying the terms used among studies will benefit the communication of knowledge. Second, questions like whether POCD should be defined as a general cognitive decline that include other forms such as postoperative delirium, or they should be considered as separate unique illnesses, and whether or not young patients should be included when POCD is discussed, need to be answered. Only after answering these questions, will the study of POCD be less disputable. Third but not the least, efforts should be made trying to make "golden-standard" in regard of the testing methods of POCD both clinically and pre-clinically.Summary: Although lots of researches have been conducted on POCD, the understanding of this clinical syndrome is still very limited. There are currently many disputes regarding almost every aspect of POCD. It's time for clinicians and scholars to strike some fundamental consensus for the better investigation of POCD. How to find a way to increase the rigor of experimental design is an important question that still seeks answers. Citation:  Ni An, Wei-Feng Yu. Difficulties in understanding postoperative cognitive dysfunction. J Anesth Perioper Med 2017; 4: 87-94. doi: 10.24015/JAPM.2017.0010This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.