Maternal Awareness and Neonatal Outcome after Anesthetic Induction with Thiopental-Ketamine or Propofol for Cesarean Section

Kim, Jong Hak; Lee, Choon Hi; Kim, Chi Hyo

Abstract

Conscious awareness with recall has always been of major concern to both patients and anesthesiologists and can, particularly when pain is experienced, lead to serious psychological sequelae characterized by a form of neurosis. And the unconsciousness storing of a traumatic memory may well act as a chronic psychic irritant. This study was designed to evaluate the effects of anesthetic induction with thiopental-ketamine and propofol on maternal awareness and neonatal outcome during cesarean section. Forty pregnant women(ASA class 1 or 11) undergoing cesarean section under general anesthesia were allocated randomly to receive either thiopental(4 mg/kg, 250 mg maximum)-ketamine(20 mg)(n=20) or propofol(2 mg/kg)(n=20). Using the isolated forearm technique, the incidence of maternal intraoperative awareness was assessed. Following recovery from anesthesia and 24 hour later, the patients were interviewed to assess any recall, dream or hallucination. And the Apgar scores of newborn at one and five minutes, as well as their umbilical blood gases also evaluated. The incidence of maternal awareness signaled by flexing fingers in respose to voice commands was significantly lower in thiopental-ketamine group(70%) than propofol group(95%)(p<0.05). And 15% of patients receiving thiopental-ketamine and 20% of propofol group made a fist(indicating pain perception). Nine patients had postoperative recall of intraoperative awareness, four in the thiopental group and five in the propofol group, but only one patient in each group remembered one of six target words. No postoperative hallucination, dream or dysphoria(including pain) were noted. The maternal intraoperative cardiovascular responses among the groups were similar. There were no significant differences in Apgar scores, maternal and umbilical blood gas values. Our data indicate that thiopental-ketamine and propofol as induction agent was associated with very high rate of maternal awareness without unpleasant recall and neonatal depression.