ABSTRACT
The maternal and neonatal effects of 50% O2 -50% N2O alone and 50r% O2-5O% N2O combined with 0.5% halothane or 1% enflurane were studied in 37 parturients undergoing general anesthesia for cesarean section, All patients received thiopental and succinrlcholine for induction and were intubated and ventilated with a tidal volume of 10m1/kg and a rate of 107 breaths/min. ulltil the delivery. Two of 11(18%) patients given O2-N2O alone had recall; none in those patients receiving a potent inhalation agent had any recall. Blood loss was similar in 7tle two groups. There were no statistically significant differences between groups in induction-7odeliverr and uterine incision-t7-delivery intervals, the frequen-cies of Apgar score<7 at and 5 min., maternal and fetal blood 7as tensions, and acid-base balance. 1t is concluded that analgesic concentrations of halothane and enflurane can be safely added to 50% O2-5O% N2O to prevent maternal awareness during general anesthesia for cesarean section while maintaining normal maternal and neonatal conditions.