The Effect of Bispectral Index Monitoring on Anesthetic Use and Recovery in Children Anesthetized with Sevoflurane in Nitrous Oxide

Abstract
The utility of bispectral index (BIS) monitoring to guide anesthetic administration has been demonstrated in adults. This prospective, randomized observer-blinded study was designed to evaluate the effect of BIS monitoring on anesthetic use and recovery characteristics in pediatric patients. After data collection in 38 historical controls, 202 patients age 0–18 yr were randomized into one of two groups: standard practice (SP) and BIS guided (BIS). Patients age 0–3 yr undergoing inguinal hernia repair (IH) and patients age 3–18 yr undergoing tonsillectomy and/or adenoidectomy (TA) were selected. All patients were anesthetized with sevoflurane in 60% N2O/O2. Hernia patients also received a caudal epidural anesthetic before surgery. In the BIS group, anesthetic delivery was adjusted in an effort to achieve a target BIS of 45–60 during maintenance and 60–70 during the last 15 min of the procedure. BIS was recorded throughout surgery in all patients, but data were unavailable to the anesthesiologist in the SP group. In the TA patients, BIS monitoring was associated with a significant reduction in end-tidal sevoflurane concentration during maintenance (2.4 ± 0.6%, SP and 1.8 ± 0.4% BIS, mean ± sd) and during the last 15 min of the procedure (2.1 ± 0.7, SP and 1.6 ± 0.6, BIS). There was a 25%–40% decrease in measured recovery times. In the patients 0–6 mo of age undergoing IH, sevoflurane concentrations during maintenance (2.0 ± 0.4% SP, 0.9 ± 0.8 BIS), during the last 15 min (1.6 ± 0.4% SP, 0.6 ± 0.6% BIS), and at the end of the procedure (1.1 ± 0.6% SP, 0.3 ± 0.3% BIS) were smaller in the BIS group. Emergence and recovery measures were unaffected by BIS titration. In the children 6 mo-3 yr of age, there were no significant differences between the SP and BIS groups in anesthetic use or recovery measures.