Effect of age and sedative agent on the accuracy of bispectral index in detecting depth of sedation in children

OBJECTIVE. This study evaluated age-and sedative agent -related differences in bispectral index across observed sedation levels in a large sample of children < 18 years of age. PATIENTS AND METHODS. With institutional review board approval and waiver of consent, data from 4 independently conducted studies were combined in a secondary analysis of 3373 observations from 248 children aged 1 month to 18 years. In these studies, bispectral index values of sedated children were recorded in a blinded fashion, and sedation depth was scored using the University of Michigan Sedation Scale ( UMSS). Bispectral index was evaluated across UMSS scores for several age groups and during use of each sedative agent ( with/ without opioids). RESULTS. There was a moderate inverse correlation between bispectral index and UMSS for all age groups. There were significant differences in bispectral index across UMSS and between each sedation level except UMSS 3 to 4 in all the age groups and UMSS 0 to 1 in infants. The mean bispectral index and the cutoff values on the receiver-operating-characteristic curve for mild, moderate, and deep sedation were significantly lower in infants <= 6 months compared with older children at each sedation level. Bispectral index was reasonably sensitive and specific in differentiating mild ( UMSS 0 -1) from deeper ( UMSS 3 -4) levels of sedation but poorly differentiated between moderate and deep levels of sedation in all age groups. There was a moderate correlation between bispectral index and UMSS during the use of chloral hydrate, pentobarbital, propofol, and midazolam but poor correlation during ketamine or opioid use. Bispectral index values were significantly lower during deep sedation with propofol and pentobarbital compared with midazolam and chloral hydrate. CONCLUSIONS. Our findings suggest that, although bispectral index may differentiate light from deep sedation in most children, bispectral index must be interpreted cautiously in sedated children, with particular consideration given to patient age and use of sedative agents.