BIS Monitoring During Sevoflurane Anesthesia Induction in Children

Abstract

Objective: to estimate the time course of changes in the BIS index during rapid, over-pressure, induction of anesthesia with sevoflurane in children. Subjects and methods. Twenty-three children aged 6 months to 12 years were examined during rapid inhalation induction of sevoflurane anesthesia at short-term facial plastic surgery. The BIS index as a criterion for depressed consciousness during anesthesia and systemic hemodynamic parameters, were studied. Results. The anesthesia induction protocol that envisaged the initial inhalation of high (8%) sevoflurane concentrations in a 100% oxygen stream with a gradual decrease in the concentration of the anesthetic to 4 and 2% by minutes 4 and 8, respectively, after the initiation of its inhalation was found to achieve an adequate steady depth of depressed consciousness, as confirmed by the values of the BIS index. The latter reduced to 51.56±4.89 and 45±3.12 within the first minute after the initiation of sevoflurane inhalation and by the end of the second minute, respectively, which suggested deep sedation. The minimum value of the index was 39.00±1.72 at minute 5. The found hemodynamic changes were induced by the inhaled anesthetic and did not exceed the admissible values. Conclusion. The estimation of the changes in brain electric activity during the described technology of anesthesia induction has suggested that the procedure for BIS index recording is of high prognostic value in preventing possible impairments in anesthetic maintenance, i. e. inadequate or excess depressed consciousness. Key words: anesthesia induction, children, sevoflurane, inhalation anesthesia, BIS index, sedation.