Background Highly structured electroencephalography (EEG) oscillations can occur in adults during etomidate-induced general anesthesia, but the link between these two phenomena is poorly understood. Therefore, in the present study, we investigated the electroencephalogram dynamics of etomidate-induced loss of consciousness (LOC) in order to understand the neurological mechanism of etomidate-induced LOC. Methods This study is a prospective observational study. Etomidate-induced anesthesia was performed on eligible patients undergoing elective surgery. We analyzed EEG data from 20 patients who received etomidate for the induction of general anesthesia. We used power spectra and coherence methods to process and analyze the EEG data. Our study was based on 4-channel EEG recordings. Results Compared with the baseline (awake period), etomidate induced an increase in power in delta, theta, alpha and beta waves during LOC. Compared with the awake period, the delta-wave (1–4 Hz), alpha-wave(8–13 Hz), and theta-wave(4–8 Hz) coherence increased significantly during LOC, while the slow-wave (< 1 Hz) coherence decreased. However, the delta wave (1.0–4.0 Hz) during etomidate-induced LOC was more coherent than during the awake period (1.86–3.17 Hz, two-group test for coherence, p < 0.001). Conclusions The neural circuit mechanism of etomidate-induced LOC is closely related to the induction of oscillation in delta, theta, alpha and beta waves and the enhancement of delta-wave coherence. Trial registration ChiCTR1800017110

BackgroundHighly structured electroencephalography (EEG) oscillations can occur in adults during etomidate-induced general anesthesia, but the link between these two phenomena is poorly understood. Therefore, in the present study, we investigated the relationship between the neurological mechanism of etomidate-induced loss of consciousness (LOC) and electroencephalogram dynamics of etomidate-induced loss of consciousness.MethodsEtomidate-induced anesthesia was performed on eligible patients undergoing elective surgery. We analyzed EEG data from 20 patients who received etomidate for the induction of general anesthesia. We used power spectra and coherence methods to process and analyze the EEG data.ResultsCompared with the baseline (awake period), etomidate induced an increase in power in each band during loss of consciousness. Compared with the awake period, the delta-wave (1–4 Hz) coherence increased significantly during loss of consciousness, while the slow-wave (<1Hz) coherence decreased.ConclusionsThe neural circuit mechanism of etomidate-induced loss of consciousness is closely related to the induction of oscillation in each EEG band and is closely related to the enhancement of delta-wave, alpha-wave, and theta-wave coherence.Trial registrationChiCTR1800017110.