Postoperative Cognitive Dysfunction after Noncardiac and Nonneurologic Surgery: An Integrative Review

Postoperative cognitive dysfunction (POCD), a subtle change in patients' cognition that occurs after anesthesia and surgery, is a major concern for the growing, elderly population. The purpose of this integrative review was to examine the state of the science of POCD after noncardiac surgery. English-language research articles published from 2004 until May 2015 in adults were reviewed. A literature search revealed 587 studies with 16 articles meeting inclusion criteria. Six research domains were identified; 2 areas-anesthetic technique and biomarkers-were the focus of this review because there were more than 3 studies in each area. Bispectral index monitoring, as an anesthetic technique to decrease the incidence rate of POCD, was a major focus of research studies (n = 4). Based on the quality appraisal and study findings, the reviewer recommends that higher bispectral index levels of 40 to 60 be maintained to decrease short-term POCD. Further research is needed for the use of biomarkers as risk factors in POCD prevention research. Overall, the review was limited by methodologic weaknesses and a lack of standardized neuropsychological testing in studies. Further research is needed for the use of other anesthetic techniques and biomarkers in the study of POCD.