Effects of Midazolam on CNS and Antagonistic Effect of Flumazenil

Choi, Sae Jin; Han, Neung Hee; Kim, Moon Ho; Son, Soo Chang; Lee, Jung Un

Abstract

The effects of midazolam and diazepam which were used as an induction agent of general anesthesia were evaluated. And flumazenil which is a potent competitive inhibitor of the specific binding of benzodiazepines at the receptor level was evaluated too. Sixty patients were divided into three groups as follows: Group I (n=20); Midazolam (average 0.24 mgkg-1) was administered as an induction agent and flumazenil (average 0.24 mgkg-1) was administered in recovery room Group II (n=20); Diazepam (average 0.35 mgkg-1) was administered as an induction agent and flumaxenil (average 0.25 mgkg-1) was administered in recovery room Group III (n=20); Midazolam (average 0.24 mgkg-1) was administered as an induction agent and normal saline was administered in recovery room instead of flumaxenil The result were as follows: 1) Systolic and diastolic blood pressure and heart rate were not changed significantly, except diastolic blood pressure decreased significantly (p<0.05) in group II, after intravenous administration of midazolam and diazepam. But these were all increased significantly (p<0.001) after endotracheal intubation in all groups. 2) Systolic and diastolic blood preasure and heart rate were not changed significantly after intravenous administration of flumazenil in group I, II and there were no significant differences between each groups. 3) Tidal volume was increased significantly (p<0.05) in group 1 from 15 min after administration of flumazenil. There were no significant changes in all groups in respiratory rate. SaO2 was increased significantly (p<0.05, p<0.001) in group I, II from 5 min after administration of flumazenil. But it was increased significantly (p<0.05) in group III from 20 min after administration of normal saline too. EtCO2 was decreased insignificantly in all groups. 4) Recovery from anesthesia according to Modified Steward Coma Scale was much improved immediately after administration of flumazenil and was significant (p<0.001) statistically in group I, II from 5 min after administration of flumazenil and reached complete recovery from 20 min after administration of flumaxenil. It was increased gradually and become significant in group III from 10 min after administration of normal saline. These changes of group I, II were significant (p<0.05) compared with group III and reached complete recovery from 60 min after administration of flumazenil.