Preventive effect of ephedrine to counteract hemodynamic changes following induction of anesthesia with propofol and remifentanil

One of the complications of induction of anesthesia by propofol and remifentanil is a substantial decrease in arterial blood pressure and heart rate. In this study, two different doses of prophylactic ephedrine for coping with hemodyna-mic changes due to induction of anesthesia with propofol and remifentanil were investigated. In this double-blind randomized clinical trial, 143 patients (ASA I and II) candidate for minor elective surgery under general anesthesia, randomized to three groups: normal saline, ephedrine (0.07 mg/kg) and ephedrine (0.15 mg/kg). Anesthesia was induced in all groups with propofol (2.5 mg/kg) and remifentanil (3 µg/kg). No neuromuscular blocking agent was used. The patient's hemodynamic status was assessed in 4 steps: immediately before, 2 minutes after induction of anesthesia, and 1 and 5 minutes after intubation. There was a significant decrease in average systolic, diastolic and mean arterial pressures and heart rate in all three groups after induction of anesthesia. Between then the control group revealed to have the most significant decline and the ephedrine (0.15 mg/kg) group had the least. Our study showed that administration of ephedrine (0.15 mg/kg), but not ephedrine (0.07 mg/kg), compared with control group (Normal Saline), can be significantly effective to prevent hemodynamic changes following induction of anesthesia with propofol and remifentanil.