Effect of General Anesthesia on Postoperative Cognitive Function in Elderly Patients

Abstract

The prevalence of postoperative cognitive dysfunction continues to be significant following surgical procedures. It has been posited that external factors, among which the type of anesthesia plays a vital role, are significant contributors to POCD. In older adults, cognitive decline post-surgery can lead to devastating physical, psychological, and societal impacts. Advancing our comprehension of cognitive deterioration postoperatively is critical for eradicating this potentially avoidable contributor to cognitive decline. Therefore, a thorough grasp of the cognitive repercussions of various anesthetic agents used intraoperatively has become crucial. This surge of interest has propelled research focusing on the repercussions of general anesthesia on post-surgical cognitive abilities. The objective of this literature review is to enrich readers' insights into POCD among the geriatric demographic and to scrutinize the evidence of how various anesthetic components—mainstay anesthetics, supplemental agents, and sedatives—influence postoperative cognition. Prior to the 1950s assumptions, it was surmised that anesthesia merely rendered cerebral functions dormant during surgery, with normalcy resuming upon awakening. Contemporary understanding now acknowledges the nuanced impact of anesthetics, which instigate distinctive alterations in specific cerebral activities and memory capacities. Concerns about post-surgical cognitive deficit burgeoned with the advent of inhalational anesthetic pharmacology, paralleled by heightened life expectancy and health service utilization in the aging population. While minor surgical interventions like dental extractions, often under local anesthesia, were thought to yield better cognitive outcomes, this notion was upended by Bedford's revelation in 1960 that major surgical procedures such as coronary bypass, involving cardiopulmonary bypass and extended hypothermia, markedly disrupted cognitive faculties. This link between significant surgical interventions and cognitive impairment fueled further inquiry into the influence of surgery and anesthetic agents on postoperative brain function. The late 1970s witnessed heightened awareness of postoperative "forgetfulness" in the aged, evolving into substantial focus in the late 1990s. At that point, profound documentation surfaced indicating cognitive decline post-surgery was pervasive across all ages but was especially pronounced in elderly individuals—representing a critical public health concern. The era following this revelation has witnessed an avalanche of studies probing into POCD.