Generally, 0.6-0.7 MAC of anesthetics are used to minimize the effect of anesthetics on the fetus during cesarean section. Therefore the possibility of awareness is a considerable problem in cesarean section. This study was designed to compare enflurane with sevoflurane in terms of intraoperative bispectral index (BIS) and posoperative recall during a cesarean section.

Eighty patients of ASA physical status 1 who underwent an elective cesarean section under general anesthesia were investigated in this study. Anesthesia was induced with 4 mg/kg thiopental and 1 mg/kg succinylcholine, and then maintained with O₂ (2 L), N₂O (2 L) and enflurane 1.0 vol% (n = 40) or sevoflurane 1.2 vol% (n = 40). We monitored BIS throughout the operation and recorded recall by asking the patients 1 day after the operation.

BIS values of the sevoflurane group were significantly lower than those of the enflurane group after delivery (P < 0.05). However, no patient could recall intraoperative events postoperatively.

Even though no patient could recall intraoperative events, high BIS values, which can produce awareness, were detected by 17.5% of patients after delivery in enflurane group. Therefore, sevoflurane is probably a better choice than enflurane in terms of preventing postoperative recall during cesarean section under general anesthesia.