Caudal block reduces demand of sevoflurane for adequate depth of anesthesia children

초록

Background and Goal : It is generally known that neuraxial anesthesia for adults reduces the demand for hypnotics needed for aduquate sedation. Therefore, this study examined the effect of a preoperative caudal block to the general anesthetic requirement on adequate depth of anesthesia in children. Materials and Methods : Twenty children aged 3-5 in good health who were to undergo inguinal herniorrhaphy were divided into 2 groups of 10 children each, the control and caudal block groups. Under the condition of no premedication, tracheal intubation was perforned after induction with thiopental 5㎎/㎏, rocuronium 0.6㎎/㎏, and sevoflurane 3.0 vol%. Subsequently, anesthesia was maintained with 100% O2 and sevoflurane. After setting up the Bispectral Index (BIS) monitor, a caudal block was performed to both groups differently, nomal saline 0.7 ㎖/㎏ was administered to the control group and 1.5% lidocaine 0.7 ㎖/㎏ was administered to the caudal block group. A predetermined end-tidal concentration of sevoflurane was maintained for 10 minutes, and the BIS valuem which measured 6 timess every 10 seconds, was subsequently averaged. Afterwards, the end-tidal concentration of sevoflurane was increased by 0.2 vol% in the next patient if the BIS average of the precedent patient was >50, and was decreased 0.2 vol% if the BIS average was 50. The MACBIS50 in both groups was calculated using probit analysis. The relative median potency analysis was applied to compare the results in both groups.