High-risk psychotropic medication use and delirium screening in older patients undergoing planned surgical procedures

Background

A number of commonly used psychotropic medicines increase the risk of postoperative delirium. In some cases, these medicines could be safely tapered or held prior to planned surgery, which may reduce the incidence of postoperative delirium. However, the frequency with which patients use these medicines prior to planned surgery is unknown.

Aim

To determine the prevalence of opioid analgesic, antidepressant, gabapentinoid, and benzodiazepine use prior to planned surgery, the prevalence of delirium screening before and after planned surgery, and the incidence of postoperative delirium in older patients using high-risk medicines.

Method

We conducted a retrospective analysis of electronic medical records (EMRs) from four acute-care hospitals. Patients aged 65 years or older who underwent planned surgery over a 2-week period were included. Data relating to patient age, gender, type of surgical procedure, length of surgery, type of anaesthesia, medications on admission, and 4AT delirium tests were extracted from the EMRs. This project was exempt due to the local policy requirements that constitute research by the Central Adelaide Local Health Network (CALHN) Human Research Ethics Committee (Reference no: CALHN19857). The justification for this ethics exemption was as follows: the project complies with the National Health and Medical Research Council's National statement on ethical conduct in human research, met local requirements for an audit activity, and presented no foreseeable risk of patient harm.

Results

The study included 158 participants with a median age of 75 years, of whom 41% were taking a medicine associated with increased risk of postoperative delirium prior to their planned surgical admission; 21% were taking an antidepressant, 15% an opioid analgesic, 13% a benzodiazepine, and 6% a gabapentinoid at the time of admission. In addition, 80% of participants had a 4AT test prior to surgery, and 61% received at least one 4AT test after surgery.

Conclusion

Among the older patients undergoing planned surgery, 41% used a medicine associated with increased risk of postoperative delirium, and not all older patients received delirium screening prior to or after surgery.