Intravenous ephedrine, phenylephrine, and ketamine for attenuation of hypotension associated with induction of general anesthesia with propofol

Abstract

Background and objective Hypotension and bradycardia remain the major adverse effects of propofol during induction of general anesthesia. Several drugs were studied to prevent these adverse effects. In our study, we compare the effect of mixing ephedrine, phenylephrine, or ketamine with propofol to attenuate its hypotensive effect during induction of general anesthesia. Materials and methods A total of 120 patients of both sexes between 20 and 50 years of age and ASA I–II physical status undergoing elective ambulatory surgeries under general anesthesia were included in our study. Patients were randomly allocated into four groups (30 patients each): group C (the control group), which received plain propofol; group E (the ephedrine group), which received 15 mg of ephedrine premixed with propofol; group Ph (the phenylephrine group), which received 100 μg of phenylephrine premixed with propofol; and group K (the ketamine group), which received 30 mg of ketamine premixed with propofol. In all groups, mean arterial blood pressure (MABP) and heart rate (HR) were recorded at baseline (before induction) and then every 1 min until 6 min after induction. Results Addition of ephedrine, phenylephrine, or ketamine to propofol during general anesthesia induction can significantly attenuate hypotension and bradycardia. In the control group, the MABP dropped from 91.96±3 mmHg just before induction to 75.6±8.7 mmHg at 6 min after induction. HR in the control group dropped from 83.76±7.29/min just before induction to 75.3±12/min at 6 min after induction. The drop in MABP and HR were nonsignificant in the other three groups. Conclusion Mixing propofol with ketamine, ephedrine, or phenylephrine before induction can attenuate its hypotensive and bradycardic effects.