Correlation of bispectral index with end-tidal sevoflurane concentration and age in infants and children.
BACKGROUND
The bispectral index (BIS) has been evaluated as a tool for measuring depth of anaesthesia, but the use of BIS in a paediatric population is still controversial. This study was designed to evaluate the correlation of BIS with end-tidal sevoflurane concentration and age in infants and children.


METHODS
Eighty-one patients undergoing elective urology surgery were allocated into three age groups; 6 months to 2 yr (n=28), 3-7 yr (n=33), and 8-12 yr (n=20). Sevoflurane was administered to achieve steady-state end-tidal sevoflurane concentrations (ET(sevo)) of 2.0, 3.0, and 4.0%; these were achieved consecutively either from the lowest or from the highest concentration. The BIS (version XP) was monitored continuously.


RESULTS
In all three groups, BIS decreased significantly when ET(sevo) increased from 2.0 to 3.0% but there was a paradoxical increase in BIS values when ET(sevo) increased from 3.0 to 4.0%. The non-linear regression analysis showed a significant correlation between BIS and age at each ET(sevo). The younger patients showed the higher BIS values.


CONCLUSIONS
In children aged 6 months to 12 yr, the BIS increased paradoxically as ET(sevo) increased from 3.0 to 4.0%. BIS values showed a wide variation in the same ET(sevo) and the age itself was considered to be a factor affecting the BIS values.
Kim
H S
HS
Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Korea.
Oh
A Y
AY
Kim
C S
CS
Kim
S D
SD
Seo
K S
KS
Kim
J H
JH
D000375:Aging / Q000502:physiology*; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D002648:Child; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007223:Infant; D008738:Methyl Ethers / Q000494:pharmacology*; D016343:Monitoring, Intraoperative / Q000379:methods*; D011446:Prospective Studies; D012044:Regression Analysis; D000077149:Sevoflurane; D013520:Urologic Surgical Procedures
D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane