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

There have been few comparative studies using electroencephalogram (EEG) spectral characteristics during the induction of general anesthesia for cesarean section. This retrospective study investigated the differences in the depth of anesthesia through EEG analysis between propofol- and thiopental-induced anesthesia. We reviewed data of 42 patients undergoing cesarean section who received either thiopental (5 mg/kg) or propofol (2 mg/kg). EEG data were extracted from the bispectral index (BIS) monitor, and 10-second segments were selected from the following sections: 1) Stage I, BIS below 60 after induction; 2) Stage II, after intubation completion; 3) Stage III, end-tidal sevoflurane above 0 vol%. The risk of awareness was represented by the BIS and entropy measures. In Stage III, the thiopental group (n = 20) showed significantly higher BIS value than the propofol group (n = 22) (67.9 [18.66] vs 44.5 [20.63], respectively, p = 0.002). The thiopental group had decreased slow-delta oscillations and increased beta-oscillations as compared to the propofol group in Stages II and III (p < 0.05). BIS, spectral entropy, and Renyi permutation entropy were also higher in the thiopental group at Stages II and III (p < 0.05). In conclusion, frontal spectral EEG analysis demonstrated that propofol induction maintained a deeper anesthesia than thiopental in pregnant women.

Accidental awareness while under general anaesthesia.

Accidental awareness during general anaesthesia may cause many intraoperative discomforts and bring further moderate to severe long-term symptoms including flashbacks, nightmares, hyperarousal or post-traumatic stress disorder. The incidence of awareness varied from 0.017% to 4% among studies. The relatively reliable incidence of intraoperative awareness with postoperative recall is 0.02%. The reason causing awareness was unclear. Insufficient anaesthetic dosing was thought as the principal cause. Even awareness was not comprehensively understood, some endeavors have been raised to prevent or reduce it, including i) Reducing the insufficient anaesthetic dosing induced by negligence; ii) Providing close clinical observation and clinical parameters from the monitor such as bispectral index or electroencephalogram, as well as isolated forearm technique and passive brain-computer interface may bring some effects sometimes. Because current studies still have some flaws, further trials with new detecting approach, superior methodology and underlying aetiology are needed to unfasten the possible factors causing awareness.

Emergence from anesthesia: a winding way back.

none.

Awareness during general anaesthesia in the first 4,000 incidents reported to webAIRS.

The aim of this study was to analyse the incidents related to awareness during general anaesthesia in the first 4,000 cases reported to webAIRS-an anaesthetic incident reporting system established in Australia and New Zealand in 2009. Included incidents were those in which the reporter selected "neurological" as the main category and "awareness/dreaming/nightmares" as a subcategory, those where the narrative report included the word "awareness" and those identified by the authors as possibly relevant to awareness. Sixty-one awareness-related incidents were analysed: 16 were classified as "awareness", 31 were classified as "no awareness but increased risk of awareness" and 14 were classified as "no awareness and no increased risk of awareness". Among 47 incidents in the former two categories, 42 (89%) were associated with low anaesthetic delivery and 24 (51%) were associated with signs of intraoperative wakefulness. Memory of intraoperative events caused significant ongoing distress for five of the 16 awareness patients. Patients continue to be put at risk of awareness by a range of well-described errors (such as syringe swaps) but also by some new errors related to recently introduced anaesthetic equipment, such as electronic anaesthesia workstations.

Is hyperlipidemia a potential protective factor against intraoperative awareness in cardiac surgery?

BACKGROUND: Intraoperative awareness is a dreaded complication that leads to psychological sequelae such as posttraumatic stress disorder, especially in patients undergoing cardiac surgery. This study investigated the incidence of awareness among patients receiving cardiac surgery and sought to identify the risk factors contributing to intraoperative awareness. METHODS: Patients with informed consent undergoing cardiac surgery from June to September in 2012 were enrolled. At least one structured interview was performed postoperatively with the modified Brice Interview Questionnaire to identify intraoperative awareness as confirmed awareness, possible awareness, and no awareness. Confirmed awareness events reported by patients were classified into different categories with the Michigan Awareness Classification Instrument. The questionnaire results were combined with the patient medical records. A logistic regression model was used to analyze the risk factors that may have led to intraoperative awareness. RESULTS: An estimated 2136 patients were included, and 1874 patients completed at least one interview. 83 patients (4.4 %) were identified as possible or confirmed awareness, among which 46 (2.5 %) reported confirmed awareness. Patients who experienced confirmed awareness were mostly of Class 1 and 2, 15 and 24 patients respectively, which represented isolated auditory and tactile perceptions. And 11 patients reported feelings of distress intraoperatively. Hyperlipidemia was associated with intraoperative awareness (OR = 0.499, 95 % CI = 0.252-0.989, p = 0.043) and using chi-square test, however, no significance was found with logistic regression. CONCLUSION: Patients undergoing cardiac surgery are at high risk for intraoperative awareness. Distress is a common feeling in patients with intraoperative awareness. Hyperlipidemia is a potential protective factor for intraoperative awareness in cardiac surgery.

[Awareness in paediatric anaesthesia: Review of the literature]. / Le réveil peropératoire en anesthésie pédiatrique: Revue de la littérature.

Awareness, or unwanted recall of intraoperative events during general anesthesia, is not a frequent complication. For adul ts, this complication can lead to adverse psychological consequences like post-traumatic stress disorder (PTSD). The incidence of awareness seems to be higher in children than in adults, although in this population, the causes and consequences of awareness remain difficult to define. Compared to adults, there are less psychological effects and complications after awareness and no PTSD has been declared in children. The revival of interest concerning awareness has been stimulated by the availability of new technologies to assess the depth of anesthesia. These monitoring seem to be more accurate in children older than 1 year. More studies are needed to evaluate these monitoring, their ability to detect awareness and, finally, to explore long term consequences of awareness in children.

Le réveil peropératoire (RPO) ou le souvenir non désiré d'évènements au cours d'une anesthésie générale (AG) est une complicat ion peu fréquente. Chez l'adulte, cette situation peut conduire à des complications psychologiques délétères comme le syndrome de stress posttraumatique (SSPT). L'incidence du RPO apparaît plus élevée chez l'enfant que chez l'adulte quoique dans cette population, les causes et les conséquences du RPO restent difficiles à définir. Comparativement à l'adulte, il n'y a pas d'effets psychologiques délétères après le RPO chez l'enfant et aucun SSPT n'a été déclaré. Le regain d'intérêt concernant le RPO a été stimulé par l'apparition de nouvelles technologies permettant de mesurer la profondeur de l'anesthésie. Ces moniteurs semblent assez précis chez les enfants de plus d'un an. De nouvelles études sont nécessaires pour évaluer l 'uti lité de ces moniteurs à détecter et à prévenir le RPO. Les conséquences du RPO à long terme chez l'enfant devraient également être explorées.