Feasibility of Closed-loop TCI Based on New EEG Baseline in the Presence of Low Dose of Esketamine

The propofol-remifentanil closed-loop TCI system based on EEG guidance has been clinically verified, which enables more precise anesthetic dosing. As an adjunct to anesthesia, esketamine has been shown to stabilize hemodynamics, reduce opioid use, and reduce postoperative nausea and vomiting. However, due to its specific electroencephalographic excitatory effect, esketmine's clinical use in close-loop system has been limited. The aim of this experiment was to determine the specific impact of esketamine on EEG and thus obtain a new EEG baseline for close-loop system, which can broaden the application of close-loop TCI system in combination with other drugs.

The trial is devided into two phases. In the first phase, we statistically analyzed and calculated the changes of BIS by collecting a sample size of EEG changes after administering low dose of esketamine. We used 0.2 mg/kg as a loading dose and followed by a rate of 5ug/kg/min as esketamine administration and observe the changes in BIS each for 30 minutes. In the second phase, we obtain the BIS quantification value N with the addition of a small dose of esketamine in the first phase and thus obtain a new EEG baseline 50+N. By comparing this EEG-adjusted group with the control group, which run the close-loop system based on original BIS baseline without esketamine, whether the closed-loop system can be better applied based on the new BIS baseline under low dose of esketamine.