The Median Effective Dose (ED50) of cis-Atracurium for Laryngeal Mask Airway Insertion during General Anaesthesia for Patients Undergoing Urinary Surgery

Abstract

Background In clinical practice, the laryngeal mask airway is an easy-to-use supraglottic airway device. However, the cis- atracurium dosage for laryngeal mask insertion is not standardised. We aimed to determine the optimal dose of cis- atracurium using a sequential method for successful laryngeal mask insertion. Methods : The cohort study protocol is registered at clinicaltrial.gov (NCT-03668262). Twenty-three patients undergoing elective urinary surgery were sequentially administered doses (μg· kg -1 ) of cis- atracurium as follows: 150, 100, 70, 50, 30, and 20. The main outcome was the response to laryngeal mask airway insertion: ≥16 points and <16 points indicated “satisfactory” and “unsatisfactory” responses, respectively. The median effective dose was estimated using the mean of the seven crossovers from “satisfactory” and “unsatisfactory” responses. The primary outcome was to determine the median effective dose (ED50) of cis- atracurium for laryngeal mask airway insertion. Results : The median effective dose of cis- atracurium was 26.5 μg·kg -1 (95% CI 23.6-29.8) using the sequential method. The heart rate was decreased in the 50μg·kg -1 group compared to the 30μg·kg -1 group at timepoints T7, T8, and T10 ( P = 0.0482, P = 0.0460, and P = 0.0236, respectively), but no difference with 20 μg·kg -1 group. The systolic blood pressure was decreased in the 50 μg·kg -1 group compared to the 20 μg·kg -1 group at timepoints T2, T3, T4 ( P = 0.0159, P = 0.0233, and P = 0.0428, respectively). The train-of-four value was significantly lower in the 50 μg·kg -1 group than in the 30 μg·kg -1 group at timepoint T3( P = 0.0326). Conclusions : The ED50 of cis- atracurium was 26.5 μg·kg -1 for laryngeal mask airway insertion.

Determination of the median effective dose of sufentanil for inhibiting the laryngeal mask insertion response in geriatric patients: a prospective, double-blinded, dose–response trial

“…The present study was to determine the ED50 of sufentanil for inhibiting the LMA insertion response in geriatric patients, the probit analysis shown that the ED50 and ED95 of sufentanil were determined based on whether effective LMA insertion was achieved, and they were 0.18 μg kg −1 (95% CI: 0.16-0.21 μg kg −1 ), and the ED95 was 0.31 μg kg −1 (95% CI: 0.27-0.38 μg kg −1 ), respectively. The 3-point, 6-category scale used in the assessment of LMA insertion is a widely accepted and mature assessment method [13,14]. A comprehensive assessment of LMA insertion is carried out through two indicators of LMA insertion difficulty (mouth opening and insertion resistance) and four indicators of insertion response (swallowing, choking, head or body movement, and laryngospasm).…”