Incidence and Characteristics of Postoperative Cognitive Dysfunction in Elderly Quebec Francophone Patients

Incidence and Characteristics of Postoperative Cognitive Dysfunction in Elderly Quebec Francophone Patients Following Major Surgery Under Standardized General Anesthesia With Tight Hemodynamic Control: A Prospective Observational Study

The purpose of this study is to determine what percentage of patients have cognitive problems (for example, memory or concentration difficulties) after surgery and anesthesia, what the characteristics of these problems are, and whether they persist over time. In particular, the investigators want to study this in the French-speaking Quebec population with cognitive evaluation tools adapted for this population.

Multiple experimental and observational studies have established that a non-negligible percentage of individuals undergoing surgery and anesthesia will experience a postoperative decline in mental abilities. These cognitive changes can range from postoperative delirium to more subtle and longer lasting (weeks to months) impairments; these latter changes are often referred to in the literature as postoperative cognitive dysfunction (POCD). While the precise causes of POCD remain nebulous, a clear epidemiological risk factor is advanced age - a demographic group that accounts for an increasing percentage of elective surgeries in North America. Several RCTs have attempted to link specific aspects of anesthesia, such as depth of anesthesia, regional vs general anesthesia, hemodynamic parameters, specific anesthetic agents, etc., to the risk of developing POCD in both the elderly and general populations. Results have often been conflicting and, based on current evidence, it is difficult to identify any specific anesthetic strategy that clearly reduces the risk of POCD. The present study aims to establish the incidence and neuropsychological characteristics of POCD in the investigator's local patient population as well as to establish the feasibility of pre- and postoperative cognitive testing with assessment tools adapted to and validated for Quebec francophones in order to lay the groundwork for future studies by the research group of interventions targeting specific anesthetic techniques and monitoring modalities.

Inclusion Criteria:

• 70 years of age or older
• Undergoing elective abdominal, gynecological, or urological surgery requiring post-operative hospitalization and with an expected anesthesia time of 60 minutes or more
• Seen in pre-operative clinic of Maisonneuve-Rosemont hospital

Exclusion Criteria:

• Known dementia or other cognitive impairment
• Psychiatric disease
• Significant hearing or vision impairment
• Inability to communicate in French
• Allergy or other contraindication to medications in standardized anesthesia protocol