Postoperative Cognitive Dysfunction After Noncardiac Surgery: A Systematic Review
Stanton Newman,* Jan Stygall,*† Shashivadan Hirani,* Shahzad Shaefi,* and Mervyn Maze‡
(Anesthesiology, 106;572-590, 2007)
*Centre for Behavioural and Social Sciences in Medicine, University College London; †Department of Psychology, Thames Valley University; and ‡Department of Anaesthetics, Pain Medicine, and Intensive Care, Imperial College London, London, United Kingdom
A systematic review of the research into postoperative cognitive dysfunction (POCD) after noncardiac surgery is described to determine the status of the evidence and to examine methodologies used in studies. It demonstrates that in the early weeks after major noncardiac surgery, a substantial proportion of people manifest chronic obstructive pulmonary disease, with the elderly being more at risk. Minimal evidence was found that patients continue to show chronic obstructive pulmonary disease up to 6 months and beyond. Studies on regional versus general anesthesia failed to uncover any differences in POCD. Many studies were found to be underpowered, and numerous other methodological difficulties were identified, including different types of surgery in studies and variations in the number and range of neuropsychological tests used. A particular issue is the variety of definitions used to classify individuals as having POCD.