[Bispectral index during induction and awakening from sedation with sevoflurane for magnetic resonance imaging in children].
OBJECTIVE
To determine the bispectral (BIS) index during induction of sedation with sevoflurane and awakening in children undergoing magnetic resonance imaging (MRI).


METHODS
We studied 50 pediatric patients sedated only with 2% sevoflurane in oxygen and air administered through a face mask. BIS was monitored during induction, before MRI, after MRI, during awakening, upon first movement, and upon eye opening or first cry.


RESULTS
The scan was performed successfully in all patients (none moved during the procedure) even though there was great variability in BIS indices (before MRI, 59.5 [SD, 11.1]; after MRI, 52.8 [13.7]). BIS indices before and after MRI were correlated, although the index after MRI was significantly lower than the index before the scan (P<0.01), indicating that hypnosis became deeper during the procedure. The first spontaneous movement and crying or eye opening produced significantly higher BIS indices (P<0.01) (movement, 75.4 [15.9]; crying, 79.8 [15.6]), although variation was also greater. The BIS index did not exceed 70 for 15 patients (31.3%) upon eye opening and for 12 (27.3%) at the first cry. Children under 6 months of age had significantly lower BIS indices before and after MRI scans than did the older children (P<0.01).


CONCLUSIONS
In the absence of painful stimuli, the BIS index reflects the patient's level of hypnosis but does not predict recovery of consciousness.
Pérez Ferrer
A
A
Servicio de Anestesiología y Reanimación, Hospital Universitario La Paz, Madrid. a.perezf@telefonica.net
Gredilla
E
E
de Vicente
J
J
Reinoso Barbero
F
F
García Fernández
J
J
Gilsanz
F
F
D018685:Anesthetics, Inhalation; D002648:Child; D002675:Child, Preschool; D016292:Procedural Sedation; D004569:Electroencephalography; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008738:Methyl Ethers; D000077149:Sevoflurane
D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane