title: Onset of action between bupivacaine 0.5% and bupivacaine 0.5% plus fentanyl 75 mcg.
abstract: This study tested the hypothesis that the addition of fentanyl 75 mcg to bupivacaine 0.5% at the onset of epidural anesthesia for cesarean section reduces the onset time for T4 sensory blockade. The study was conducted in a randomized, double-blind fashion. The same observer performed sensory testing using pain to pinprick. Fourteen ASA I patients scheduled for elective cesarean section had epidural catheters placed. Group 1 (n = 7) received bupivacaine 0.5%, and group 2 (n = 7) received bupivacaine 0.5% plus fentanyl 75 mcg. Patients 5'0'' to 5'4'' in height received 15 ml, and patients 5'5'' to 5'9'' received 20 ml of bupivacaine. There were no adverse effects on the neonate or clinically important changes in maternal hemodynamics. The maternal age, height, weight, and bupivacaine dose did not differ between groups (p greater than 0.05). For group 1, the mean times for sensory loss at T7, T6, T5, and T4 were 13.1 +/- 3.8 minutes, 15.0 +/- 4.0 minutes, 16.9 +/- 4.3 minutes, and 19.3 +/- 4.9 minutes, respectively; for group 2, the mean times were 8.1 +/- 0.9 minutes, 9.9 +/- 1.1 minutes, 11.3 +/- 1.5 minutes, and 12.7 +/- 2.0 minutes, respectively. Two-factor analysis of variance between groups 1 and 2 showed a significant difference (p less than 0.0001), representing a 35% reduction of mean onset time. The coefficient of variation of the mean onset times for group 1 subjects was 26.6% +/- 1.7% and for group 2 subjects 12.7% +/- 2.2% (p less than 0.001), representing a 50% reduction in between-subject variation.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Anaesthesia, Beth Israel Hospital, Boston, MA.
authors.forename: C
authors.initials: C
authors.lastname: Johnson
authors.forename: N
authors.initials: N
authors.lastname: Oriol
authors.forename: D
authors.initials: D
authors.lastname: Feinstein
authors.forename: B J
authors.initials: BJ
authors.lastname: Ransil
mesh_terms: D000328:Adult; D000767:Anesthesia, Epidural; D000773:Anesthesia, Obstetrical; D002045:Bupivacaine / Q000008:administration & dosage*; D002585:Cesarean Section; D004311:Double-Blind Method; D004338:Drug Combinations; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage*; D006801:Humans; D011247:Pregnancy; D016032:Randomized Controlled Trials as Topic
chemical_list: D004338:Drug Combinations; D005283:Fentanyl; D002045:Bupivacaine