Reduction in the incidence of awareness using BIS monitoring

Abstract

Background: Explicit recall (ER) is evident in approximately 0.2% of patients given general anaesthesia including muscle relaxants. This prospective study was performed to evaluate if cerebral monitoring using BIS to guide the conduction of anaesthesia could reduce this incidence significantly. Patients and methods: A prospective cohort of 4945 consecutive surgical patients requiring muscle relaxants and/or intubation were monitored with BIS and subsequently interviewed for ER on three occasions. BIS values between 40 and 60 were recommended. The results from the BIS-monitored group of patients was compared with a historical group of 7826 similar cases in a previous study when no cerebral monitoring was used. Results: Two patients in the BIS-monitored group, 0.04%, had ER as compared with 0.18% in the control group (P < 0.038). Both BIS-monitored patients with ER were aware during intubation when they had high BIS values (>60) for 4 min and more than 10 min, respectively. However, periods with high

The Clinical Effectiveness of the Bispectral Index (BIS) To Reduce the Risk of Awareness for Elective Surgical Patients Undergoing General Anesthesia: A Prospective, Randomized, Double-Blind, Controlled Trial

“…BIS-guided anesthesia decreased awareness by 13.8% (95% CI (1.3%-26.4%). These results are in agreement with previous findings [13,20].…”

“…According to BIS monitoring guidelines from the manufacturer, values below 40 indicate a deep hypnotic state, which is not recommended for surgical procedures [20].…”

Effects of changing from sevoflurane to desflurane on the recovery profile after sevoflurane induction: a randomized controlled study

“…The BIS never exceeded 60 during the changing period in the desflurane group; awareness during anesthesia is unlikely when the BIS is\60. 29,30 Furthermore, none of the patients experienced awareness during anesthesia, suggesting that changing from sevoflurane to desflurane during the early part of anesthesia does not cause awareness during the changing period. The low solubility of desflurane may provide faster wash-in compared with the wash-out of sevoflurane, maintaining an adequate depth of anesthesia during the changing period.…”

BIS use in pediatric anesthesia: where are we?

“…2 Chez l'enfant, le monitorage de la profondeur d'anesthésie présente le même attrait intellectuel que chez l'adulte. L'incidence de la mémorisation peropératoire n'est à l'heure actuelle pas évaluée, cependant les changements de comportement postopératoires sont fréquemment observés chez les jeunes enfants.…”

“…In adults, the usefulness of the BIS has been shown with regard to the consumption of anesthetics or awakening time and, above all, very recently, in terms of the prevention of intraoperative memory. 2 Monitoring anesthetic depth in children is just as intellectually attractive as in the case of adults. The incidence of intraoperative memory is not being assessed currently, but post-operative behavioural changes are frequently observed in young children.…”