The Pharmacodynamic Effects of a Lower-Lipid Emulsion of Propofol: A Comparison with the Standard Propofol Emulsion

Using a randomized, double-blind protocol design, we compared a new lower-lipid emulsion of propofol (Ampofol®) containing propofol 1%, soybean oil 5%, and egg lecithin 0.6% with the most commonly used formulation of propofol (Diprivan®) with respect to onset of action and recovery profiles, as well as intraoperative efficacy, when administered for induction and maintenance of general anesthesia as part of a "balanced" anesthetic technique in 63 healthy outpatients. Anesthesia was induced with sufentanil 0.1 μg/kg (or fentanyl 1 μg/kg) and propofol 2 mg/kg IV and maintained with a variable-rate propofol infusion, 120-200 μg · kg^-1 · min^-1. Onset times to loss of the eyelash reflex and dropping a syringe were recorded. Severity of pain on injection, speed of induction, intraoperative hemodynamic variables, and electroencephalographic bispectral index values were assessed. Recovery times to opening eyes and orientation were noted. The results demonstrated that there were no significant differences between Ampofol® and Diprivan® with respect to onset times, speed of induction, anesthetic dose requirements, bispectral index values, hemodynamic variables, recovery variables, or patient satisfaction. However, the incidence of pain on injection was more frequent in the Ampofol® group (26% versus 6%, P < 0.05). We conclude that Ampofol® is equipotent to Diprivan® with respect to its anesthetic properties but was associated with a more frequent incidence of mild pain on injection.