RESUMO
BACKGROUND: Propofol is a useful induction agent, but it can cause hypotention and bradycardia. Meanwhile, ephedrine has alpha-vasoconstriction and beta-cardiac stimulant effect. The purpose of this study was to assess the hemodynamic effects of adding various doses of ephedrine to propofol to obtund adverse hemodynamic response and to determine the optimal dose. METHODS: Unpremedicated 120 ASA physical status I adult patients (20~50yrs) scheduled for elective surgery were randomly allocated into four groups according to the doses of ephedrine added to propofol (1%, 20 ml). Group 1 (control group) was given propofol alone and 10, 15 and 20 mg of ephedrine was added to propofol in Group 2, 3 and 4, respectively (n=30 for each group). Propofol was loaded at 150 ml/hr using a syringe pump and no response to verbal command was ascertained as the end-point of induction. Vital signs and SpO2 were checked every 1 min during the induction period. RESULTS: In group 1, there was a significant decrease in both systolic and diastolic pressure prior to intubation. Group 2 and 3 showed relatively stable hemodynamic changes and significant systolic or diastolic changes occured only in the pre or post 1 min periods of intubation. But, in pulse rate, group 3 showed significant change 1 and 2 min after intubation, in contrary to group 2. Group 4 showed significant changes in systolic and diastolic pressure 1 and 2 min after intubation, and in pulse rate throughout the postintubation period. CONCLUSIONS: Ephedrine 10mg may be safely employed to reduce the hemodynamic changes during induction preiod with propofol.