Propofol Requirement and EEG Alpha Band Power During General Anesthesia Provide Complementary Views on Preoperative Cognitive Decline

Abstract

<b>Background:</b> Although cognitive decline (CD) is associated with increased post-operative morbidity and mortality, routinely screening patients remains difficult. The main objective of this prospective study is to use the EEG response to a Propofol-based general anesthesia (GA) to reveal CD. <b>Methods:</b> 42 patients with collected EEG and Propofol target concentration infusion (TCI) during GA had a preoperative cognitive assessment using MoCA. We evaluated the performance of three variables to detect CD (MoCA < 25 points): age, Propofol requirement to induce unconsciousness (TCI at SEF₉₅: 8-13 Hz) and the frontal alpha band power (AP at SEF₉₅: 8-13 Hz). <b>Results:</b> The 17 patients (40%) with CD were significantly older (<i>p</i> < 0.001), had lower TCI (<i>p</i> < 0.001), and AP (<i>p</i> < 0.001). We found using logistic models that TCI and AP were the best set of variables associated with CD (AUC: 0.89) and performed better than age (<i>p</i> < 0.05). Propofol TCI had a greater impact on CD probability compared to AP, although both were complementary in detecting CD. <b>Conclusion:</b> TCI and AP contribute additively to reveal patient with preoperative cognitive decline. Further research on post-operative cognitive trajectory are necessary to confirm the interest of intra operative variables in addition or as a substitute to cognitive evaluation.