BACKGROUND: The electroencephalogram-derived Bispectral Index (BIS), and the composite A-line ARX index (cAAI), derived from the electroencephalogram and auditory evoked potentials, have been promoted as anesthesia depth monitors. Using an intraoperative wake-up test, we compared the performance of both indices in distinguishing different hypnotic states, as evaluated by the University of Michigan Sedation Scale, in children and adolescents during propofol-remifentanil anesthesia for scoliosis surgery. Postoperative explicit recall was also evaluated. METHODS: Twenty patients (aged 10-20 yr) were enrolled. Prediction probabilities were calculated for induction, wake-up test, and emergence. BIS and cAAI were compared at the start of the wake-up test, at purposeful movement to command, and after the patient was reanesthetized. During the wake-up test, patients were instructed to remember a color, and were then interviewed for explicit recall. RESULTS: Prediction probabilities of BIS and cAAI for induction were 0.82 and 0.63 (P < 0.001), for the wake-up test, 0.78 and 0.79 (P < 0.001), and 0.74 and 0.78 for emergence (P < 0.001). During the wake-up test, a significant increase in mean BIS and cAAI (P < 0.05) was demonstrated at purposeful movement, followed by a significant decline after reintroduction of anesthesia. CONCLUSIONS: During induction, BIS performed better than cAAI. Although cAAI was statistically a better discriminator for the level of consciousness during the wake-up test and emergence, these differences do not appear to be clinically meaningful. Both indices increased during the wake-up test, indicating a higher level of consciousness. No explicit recall was demonstrated.

Additional Metadata
Keywords Adolescent, Adult, Anesthetics, Intravenous/therapeutic use, Child, Electroencephalography/*methods, Evoked Potentials, Auditory/drug effects/*physiology, Humans, Monitoring, Intraoperative/*methods, Piperidines/*therapeutic use, Predictive Value of Tests, Probability, Propofol/*therapeutic use, Scoliosis/*surgery, Wakefulness/drug effects/*physiology
Persistent URL,
Blussé van Oud-Alblas, H.J, Peters, J.W.B, de Leeuw, T.G, Vermeylen, K.T.A, Klerk, L.W.L, Tibboel, D, … Weber, F. (2008). A comparison in adolescents of composite auditory evoked potential index and bispectral index during propofol-remifentanil anesthesia for scoliosis surgery with intraoperative wake-up test. Anesthesia and Analgesia, 107(5), 1683–1688. doi:10.1213/ane.0b013e3181852d94