Accuracy of bispectral index for monitoring depth of sevoflurane anesthesia in children of different ages

Objective To evaluate the accuracy of bispectral index (BIS) for monitoring the depth of sevoflurane anesthesia in children of different ages.Methods One hundred and five children (0-14 yr) undergoing abdominal surgery were divided into 3 age groups (n=35 each): group Ⅰ 4-14 yr (older children); group Ⅱ 1-3 yr (young children) and group Ⅲ 6 months. Each C_(ET)Sev was maintained for at least 15 min. MAP, HR, P_(ET)CO_2 and BIS were monitored and recorded before anesthesia (T_1, baseline), at loss of consciousness (T_2), immediately after tracheal intuhation (T_3), at the 4 C_(ET)Sev (T_(4-7)), recovery of pharyngeal reflex (T_8), extubation (T_9) and emergence of anesthesia (T_10). Results BIS values were significantly higher in children of 1-3 yr (group Ⅱ) than in children of 3-14 yr (group Ⅰ) at T_(4,6,7). BIS values were significantly lower in infants (group Ⅲ) than in children of 3-14 yr (group Ⅰ) at T_(5-9). BIS values were significantly lower in infants (group Ⅲ) than in children of 1-3 yr (groupⅡ) at T_(3-10). There was significant negative correlation between BIS and C_(ET)Sev in all 3groups(γ=-0.768,-0.709,-0.357).Conclusion BIS can accurately reflect the depth of sevoflurane anesthesia in children (> 1 yr). BIS should be interpreted cautiously in infants (< 1 yr). Key words: Electroencephalography;  Monitoring;  intraoperative;  Child;  Sevoflurane