BACKGROUND: There is evidence that older patients experience cognitive changes after surgery compared to before. Most existing studies compare postoperative cognitive performance to the performance at a single preoperative timepoint. Therefore, it is unclear whether postoperative changes are a result of surgery or would have been expected as a continuation of a preoperative trend.
OBJECTIVE: To explore the impact of surgery on perioperative cognitive trajectories, among ≥65 years old patients waiting for ≥6 weeks before undergoing elective noncardiac surgery during the COVID-19 pandemic.
METHODS: In this proof-of-concept prospective study, cognitive performance of participants was assessed remotely at enrolment, monthly preoperatively (≥2 assessments) and at 1, 3, 6, and 12 months postoperatively, using the Cogstate Brief Battery. The association of surgery with cognitive changes was analyzed using an interrupted time-series approach.
RESULTS: In the 84 included participants, after controlling for the preoperative trend, surgery resulted in a small decline in the level of average performance on tasks assessing psychomotor function and attention from before to after surgery (p = 0.017). Postoperative trajectories showed improvement compared to preoperative ones in the psychomotor function (p = 0.008), attention (p = 0.002) and visual learning (p = 0.007). After adjusting for potential confounders, only the postoperative level change in attention remained statistically significant (p = 0.027).
CONCLUSION: In our exploratory proof-of-concept study, surgery was associated with a statistically significant level and trend change in cognitive performance, however the magnitude of the change was small and partially due to confounding. Further research with adequate power is needed to confirm our findings and elucidate factors associated with postoperative cognitive decline.
REGISTRATION: clinicaltrials.govNCT04787536.
