A randomized trial to identify the most effective dose of remifentanil during Le Fort I osteotomy

The Le Fort I osteotomy (L-I) requires extensive dissection and manipulation of tissue, causing hemodynamic instability and an undesirable postoperative stress response. This study aimed to clarify the most effective dose of remifentanil during L-I.

This study was designed as a prospective, randomized, controlled double-blinded study. Patients (American Society of Anesthesiologists physical status I to II) undergoing L-I were randomly assigned to receive anesthesia with propofol and remifentanil under 3 remifentanil dose conditions: 0.25 μg/kg/minute (group 1), 0.5 μg/kg/minute (group 2), and 0.75 μg/kg/minute (group 3). All patients underwent L-I with propofol and remifentanil target-controlled anesthesia. The study endpoints were mean arterial pressure (MAP) and heart rate. Data were recorded before L-I (20-minute period before surgery), during L-I (from the beginning of surgery to downfracture), and after L-I (20-minute period after downfracture). Average age, gender, average body mass index, aimed maxillary position, average bispectral index, average surgery time, and average blood loss also were examined. Data were analyzed using the Bartlett test and then 1-way analysis of variance with the Bonferroni multiple comparison test.

Data were obtained from 20 patients (9 men, 11 women). The average operating times for groups 1, 2, and 3 were 53.1, 46.7, and 49 minutes, respectively. The age range was 18 to 46 years (average, 26.05 yr). The rate of MAP increase from before to during L-I in group 1 was 10.8% (n = 7). The rate of MAP increase from before to during L-I in group 3 was 2.1% (n = 6). Group 3 showed a significantly lower rate of MAP increase during and after L-I compared with group 1 (P < .05).

Remifentanil administration at 0.75 μg/kg/minute stabilized hemodynamics during L-I without major side effects. Results indicated that the standard index of remifentanil administration during L-I should be 0.75 μg/kg/minute when using oxygen, propofol, and remifentanil for general anesthesia.