Intraoperative Somatosensory Evoked Potential Monitoring Decreases EEG Burst Suppression Ratio During Deep General Anesthesia

Abstract

Data from this study show that somatosensory input can evoke bursts, altering the "spontaneous" deep BS patterns (BSR(Pre) >30%). Further studies are necessary to objectively assess the clinical relevance of stimulus-induced BS reactivity during deep general anesthesia.

A Sleep‐Specific Midbrain Target for Sevoflurane Anesthesia

“…The burst suppression represents a very downregulation of cortical activity, where 95% of cortical cells are silent, and therefore mice are deeply unconscious during burst suppression. [ 7,32,33 ] When reaching deep anesthesia, burst suppression continuously occurred. The ratio of EEG theta wave to delta wave power (theta/delta ratio) was calculated, and a simple exponential function was used to fit to the theta/delta ratio y against the time x as $$$$\begin{equation}y = a\cdot{e}^{b \cdot x}\end{equation}$$$$where a and b are two fitting parameters, and parameter b is defined as the anesthesia speed.…”

“…Furthermore, some studies reported that the onset of burst suppression on the EEG was used to assess whether the subjects enter the unconscious and deep anesthetic state. [7,32,33] We further analyzed the data of photometry with this criteria. Consistently, we found that the activity of sevoflurane-activated neurons significantly increased during deep anesthetic state compared with baseline.…”

Stimulus induced bursts in severe postanoxic encephalopathy

“…Burst-suppression EEG may also respond to external stimuli. For instance, burst-suppression patterns induced by general anaesthesia can react to peripheral nerve stimulation, auditory or visual stimuli (Calin et al, 2014;Hartikainen et al, 1995). We present two patients with a postanoxic encephalopathy showing burstsuppression patterns with a remarkable response to external stimuli.…”

“…Burst-suppression is a characteristic EEG pattern, defined by attenuation or suppression during at least 50% of the recording alternated with high-voltage transients (bursts) with a duration of at least 500 ms and waveforms with at least 4 phases (Hirsch et al, 2013). Burst-suppression can be observed both in physiological conditions, for example during anaesthesia, and in pathological conditions, such as anoxia, intoxication and hypothermia (Amzica, 2009;Iyer et al, 2014;Niedermeyer, 2009;Hartikainen et al, 1995;Chemali et al, 2013).…”

Towards an electroencephalographic measure of awareness based on the reactivity of oscillatory macrostates to hearing a subject's own name

“…Identifying the times of DEM occurrence reduces the continuous multichannel EEG signal to a single binary time stream marking when the DEM signature is either present (1) or not (0). The DEM reactivity (DER) to photic stimulation (DER PHOT ) could then be calculated (Serban et al, 2022) as the change of occurrence probability during 1 min stimulation as compared with a 1 min stimulation baseline, similar to reactivity measures of the discontinuous burst-suppression EEG (Calin et al, 2014;Nita et al, 2016) that can occur in deep anaesthetic coma (Hartikainen et al, 1995). We found that DER PHOT was decreased as compared with healthy controls in a group of acute post-stroke comatose patients (Serban et al, 2022), a pathology known to be associated with DMN impairments (Dacosta-Aguayo et al, 2015;Ding et al, 2014;Jiang et al, 2018;Tuladhar et al, 2013;Zhu et al, 2019).…”