[Comparative effectiveness and tolerance study of a new galenic etomidate formula].

OBJECTIVE AND STUDY DESIGN

One of the major disadvantages of etomidate is the high frequency of pain on injection. A new galenic formulation based on a lipid emulsion for etomidate (Etomidat-Lipuro) was compared with the commercial standard (etomidate in propylene glycol, Hypnomidate) in a prospective, randomised, double-blind clinical evaluation in 232 patients undergoing elective surgery in general anaesthesia. The patients were premedicated with flunitrazepam 2 hours before the investigation. Two intravenous cannulas were inserted in veins of forearm or back of the hand. One cannula was only used for the application of etomidate and removed immediately after injection. General anaesthesia was induced with 0.3 mg/kg etomidate at an injection rate of 20 mg/30 s. If the patient did not complain of pain or other sensations during injection spontaneously, he was questioned for 15 s after beginning of injection. The arm used for application of etomidate was kept free of any manipulation during the operation and the following five postoperative days.

RESULTS

There were marked differences between the two etomidate preparations concerning venous irritation. About 20% of the patients receiving the hypnotic in propylene glycol complained spontaneously of pain on injection, whereas none with the lipid emulsion. No difference was found in the incidence of myoclonic movements. The time interval between the beginning of injection and loss of eyelid closure reflex was about 50 s and not different for the two galenic formulations. Blood pressure during and after induction of anaesthesia did not differ. The heart rate in the group of patients with etomidate in lipid emulsion was slightly increased before and immediately after intubation compared to the propylene glycol group. 4% of the patients in the propylene glycol group suffered from postoperative venous complications as reddening, swelling, induration or pain. These complications could not be seen in the lipid emulsion group.