[Fentanyl shows different effects by administration routes on bispectral index during spinal anesthesia in patients undergoing cesarean section].
BACKGROUND
Spinal anesthesia using a local anesthetic with fentanyl has been reported to induce sedation. We previously reported that the bispectral index (BIS) value was significantly decreased by spinal anesthesia using only bupivacaine and fetanyl after cesarean delivery. In the present study, we studied the effect of different fentanyl administration routes on BIS values during spinal anesthesia for cesarean section.


METHODS
Forty-six women scheduled for cesarean section were allocated into five-groups according to the route of fentanyl administration and amount of local anesthetic: intrathecal 0.5% isobaric bupivacaine 2.5 ml plus fentanyl 20 microg (n = 11), intrathecal 0.5% isobaric bupivacaine 2.5 ml plus intravenous fentanyl 100 microg (n = 12), intrathecal 0.5% isobaric bupivacaine 2.5 ml plus epidural fentanyl 100 microg (n = 8), intrathecal 0.5% isobaric bupivacaine 2.5 ml (n = 8), and intrathecal 0.5% isobaric bupivacaine 3.0 ml (n = 7). BIS values were recorded during anesthesia.


RESULTS
BIS values in intrathecal fentanyl group were lower than those of other groups (P = 0.03). The cumulative duration of BIS values 80 and below 80 was longer in the intrathecal fentanyl group than those of other groups (P = 0.004).


CONCLUSIONS
The BIS value was significantly decreased only by intrathecal fentanyl for cesarean section.
Kushida
Atsuko
A
Department Anesthesiology, Kansai Medical University, Moriguchi 570-8507.
Murao
Kouhei
K
Kimoto
Michiyo
M
Nakao
Shin-ichi
S
Shingu
Koh
K
D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D000773:Anesthesia, Obstetrical / Q000379:methods*; D000775:Anesthesia, Spinal / Q000379:methods*; D000779:Anesthetics, Local / Q000008:administration & dosage; D002045:Bupivacaine / Q000008:administration & dosage; D002585:Cesarean Section; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage* / Q000494:pharmacology; D006801:Humans; D007268:Injections, Epidural; D007278:Injections, Spinal; D011247:Pregnancy
D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D005283:Fentanyl; D002045:Bupivacaine