Psychological Effects of Explicit Recall under Sedation and after Surgery (PEERS): A Prospective Cohort Study on 2,500 Patients.

Background: Explicit recall occurring during sedation/regional anesthesia is common but has long been assumed to have no sequelae. A prospective cohort study was conducted to determine the incidence of explicit recall experience under sedation/regional anesthesia, as well as to assess the recall experiences that are associated with psychological consequences.

Methods: The study prospectively recruited 2,500 adults who underwent elective total hip or knee arthroplasty under sedation/regional anesthesia from September 2021 to March 2024 at University Hospital in London, Ontario, Canada. The primary exposure was recall experience, assessed using the modified Brice questionnaire. The co-primary outcomes included probable depression (defined as a Patient Health Questionnaire score of 8 or higher) and suspected posttraumatic stress disorder (PTSD) symptoms (defined as a Post-traumatic Stress Disorder Checklist for Civilians score of 13 or higher) at 6 weeks postoperatively. The association between specific recall experiences and the co-primary outcomes was evaluated by multivariable regression analysis. Additionally, the incidence and mental health burden related to the psychological effects of surgery in the entire cohort were assessed.

Results: A total of 2,138 patients were included in the final analysis. Explicit recall was reported by 475 participants (22.2%) but was not associated with the co-primary outcomes. Regarding surgery's overall impact, 61 participants (5%) developed new probable depression, 105 participants (5%) reported suspected PTSD, and 95 patients (4.4%) developed new suicidal ideation postoperatively. The authors estimated that 1 in 18 patients required new psychiatric consultation.

Conclusions: Explicit recall per se during sedation/regional anesthesia did not increase the odds of developing psychiatric illness. Surgery itself carries significant risks of triggering depression and PTSD that are severe enough to reach levels associated with suicidal ideation, requiring immediate mental care. This study reveals a significant, yet underappreciated, mental healthcare burden.