Peripheral deafferentation induced by epidural or spinal anesthesia reduces the degree of conical arousal in adults. This study aimed at determining if caudal blockade decreases the level of arousal, as measured by Bispeetral Index (81S) in unstimulated children and to determine if this etfect differed between age groups. Hospital ethics commiltee approval and parental consent was obtained. Children (age range : 2·S years) and infanrs (age range: 6·24 months) scheduled for below umbilical surgery that would usually require caudal local anesthesia blockade were recruited in the study. Before the procedure, subjects within €ach age group were randomized to either caudal group (I mllkg 0.25% bupivacaine), or control group (no caudal). [n all groups, anesthesia was induced with sevoflurane and maintained at a constant end-tidal concentration or I.S% sevoflurane without N]O. five minutes :lner induction, a baseline BIS was recorded (BISr). In the caudal groups, a caudal block was then performed while in the control groups no block was performed. Fifteen minutes later, the BIS was again recorded (BIS2). The change in 13I S ovcr thi ~ time period was the primary outcome (131S J. Aller measurement, subjects in the control groups received a caudal block before the stan of surgery. Twenty-nine infants and 18 children completed the stlldy protocol. In children, 13ISc was significantly different between the caudal group and control (-S.7 vs. -0.7, ?=0.04). In infants, no significant difference was detected in 13IS{ between caudal and control groups. Caudal blockade decreased the degree of arousal, as measured by UIS, in unstimulated childrcn aged 2-S years. No change in arousal was detected in inf~lIlts. |
