Comparing the effects of three different additional doses of propofol infusion on intubation condition and hemodynamic changes during general anesthesia under elective surgery: A randomized, placebo-controlled, double blind clinical trial

BACKGROUND: Laryngoscopy and endotracheal intubation can induce unfavorable hemodynamic changes as propofol itself can induce hypotension. The aim of this study was to compare the effects of three different additional doses of propofol infusion on intubation conditions and hemodynamic changes occurred after intubation. MATERIALS AND METHODS: This double-blinded prospective study was performed on 140 patients aged 18-60 who received different additional doses of propofol and were randomly allocated into 4 groups as follows: A: Received additional dose of propofol 0.5 mg/kg infused after an initial dose 1.5 mg/kg. B: Received additional dose of propofol 1 mg/kg infused after an initial dose 1 mg/kg. C: Received additional dose of propofol 1.5 mg/kg after an initial dose 1 mg/kg. D: Received propofol 2 mg/kg as a bolus with no additional dose. RESULTS: Intubation conditions were acceptable in 91.4% of Group A patients, 94.2% of Group B patients, 97.1% of Group C patients and 68.5% of Group D patients. There were no significant differences in the mean of heart rate between four groups at any time before and after laryngoscopy. Mean arterial pressure (MAP) 3 min after laryngoscopy was significantly lower in Group D versus Group A (P = 0.015) while MAP was not different at any time between other groups. CONCLUSION: Infusion of propofol 1.5 mg/kg added to initial bolus dose of propofol 1 mg/kg improves intubation conditions significantly without inducing hemodynamic changes.