3. BIS in children during maintenance anesthesia

D. Schwartz¹, Anne Wu², D. Han³, Ch. Gibson⁴, N.R. Connelly⁵

1 Assistant Professor of Anesthesiology, Tufts University School of Medicine, Director of Pediatric Anesthesia, Department of Anesthesiology, Baystate Medical Center
2 Resident in Anesthesiology, Department of Anesthesiology, Baystate Medical Center
3 Resident in Anesthesiology, UCLA School of Medicine
4 Research Nurse, Department of Anesthesiology, Baystate Medical Center
5 Professor of Anesthesiology, Tufts University School of Medicine, Director of Anesthesiology Research, Department of Anesthesiology, Baystate Medical Center

Abstract

Background and aims. The reliability of BIS monitoring in children is unclear. We decided to measure BIS levels in children during the maintenance phase of general anesthesia, when the anesthesiologist believed the children were well-anesthetized.

Methods. Following IRB approval, children ages 0-10 years undergoing elective general anesthesia had a pediatric BIS electrode placed. BIS values were recorded during anesthesia maintenance. A similar protocol was followed in adult patients.

Results. A total of 240 pediatric patients were evaluated: 62 were < 12 months of age; the remaining 178 patients were between 1 and 10 years of age. There were 94 patients with a BIS ≥ 60; (42%) were infants and (38%) children. This was higher than in the adult group (16% with a BIS ≥ 60, p < 0.0009). There was no significant difference in the use of sevoflurane, N2O, intubation (vs LMA use), or dose of intravenous opioid in the children whose BIS was < or ≥ 60. One adult (1%), 13 (21%) infants and 18 (10%) children had a BIS level ≥ 70. BIS in both pediatric groups displayed greater variability than the adult group.

Conclusion. Our results demonstrate significant variability and surprisingly high BIS values in a large portion of pediatric patients. Despite the belief that the patients were well-anesthetized, approximately 40% of infants and children had BIS ≥ 60 and 10% ≥ 70. Our data supports other studies which suggest that BIS is not a reliable monitor of anesthetic depth in children. BIS data should be interpreted cautiously, and only in conjunction with other clinical signs.

Keywords: anesthesia, awareness; monitoring, BIS; anesthesia, pediatric

J Rom Anest Terap Int 2011; 18: 95-100

BIS la copii în cursul menţinerii anesteziei generale