Comparison of electroencephalogram between propofol- and thiopental-induced anesthesia for awareness risk in pregnant women

Abstract

Some studies have suggested that EEG oscillations are related to altered states of consciousness produced by anesthetics 11-15. However, there is a lack of detailed characterization of oscillatory EEG activity regarding thiopental and propofol administration in pregnant women. Therefore, characterizing EEG spectral dynamics should help to establish the risk of awareness during general anesthesia. We aimed to investigate whether there are any differences in frontal brain oscillations between propofol-and thiopental-induced general anesthesia for cesarean section. Further, BIS and entropy analyses were also conducted to evaluate awareness risk in each group. Methods patient population. This study was approved by the Asan Medical Centre institutional review board (IRB number 2019-0737). The need for informed consent was waived, considering the retrospective nature of this analysis. The study conformed to the tenets of the Declaration of Helsinki. A retrospective analysis of EEG data recorded during elective cesarean section was conducted between September 2017 and May 2019. Our institute has traditionally used only thiopental (Pentothal sodium, JW Pharmaceutical, Seoul, Korea) for cesarean section, but there was a temporary supply interruption from November 2017 until March 2018. Propofol was then used as an alternative induction agent for cesarean section. After the re-supply of thiopental, agent selection was decided by the attending anesthesiologist. We identified all parturient women who received general anesthesia. Through chart review, parturients were divided into two groups according to the anesthetic agent: the thiopental and propofol groups. Inclusion criteria were between 20 and 44 years old, American Society of Anesthesiologist grade 1 or 2, and elective operation. Patients with the following conditions were excluded from the study: (1) cases where regional anesthesia was converted to general anesthesia; (2) exposure to sevoflurane before the induction of general anesthesia; (3) missing Vital Recorder data; (4) difficult airway management cases. Anesthetic management. Our institutional standardized anesthesia protocols were used for cesarean section. All parturient women received at least 3 min of pre-oxygenation using 100% oxygen, followed by RSI with cricoid pressure. Thiopental 5 mg/kg or propofol 2 mg/kg was administered, followed by succinylcholine 1.5 mg/kg to facilitate intubation. After disappearance of fasciculation and of the electromyography (EMG) activity bar on the BIS monitor, all patients were intubated with a 6.5-cuffed tracheal tube using a video-scope. After confirming successful intubation, rocuronium 0.5 mg/kg was immediately administered to achieve further muscle relaxation. Anesthesia was maintained with 50% nitrous oxide (N 2 O) in oxygen (6 L/min) and sevoflurane. The initially inspired concentration of sevoflurane was set at 2.0 vol% on the vaporizer until the end-tidal sevoflurane (Et-Sevo) reached 1.3 vol%. A skin incision was made after the anesthesiologist confirmed intubatio...

Intraoperative Awareness During Cesarean Delivery Under General Anesthesia

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Intraoperative Awareness in Patients Undergoing Cardiac Surgery in an Academic Center in the North of Iran

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