Effect of intranasal remifentanil Vs lidocaine on facilitation of laryngeal mask airway insertion and cardiovascular response. A double-blind clinical trial study

Background: laryngeal mask airway (LMA) insertion requires a sufficient depth of anesthesia, relaxation of the jaw muscles, and suppression of airway reflexes to tolerate it inside the hypopharynx. This study aimed to determine and compare the effect of intranasal administration of lidocaine and remifentanil on the condition of LMA insertion and cardiovascular response. Methods: This double-blind randomized clinical trial study was conducted on 60 eligible patients undergoing elective surgery under general anesthesia with LMA insertion from March 2019 to March 2020 in Faiz Hospital, Isfahan. After induction of anesthesia and before placing the laryngeal mask, remifentanil 1 µg/kg intranasally in the first group, lidocaine 2% 1 mg/kg in the second group, and normal saline with the same volume in the third group was administered. The primary and secondary outcomes of the study were patients’ demographic information (age, height, weight, BMI, ASA classification), LMA insertion condition (function of the LMA, number of attempts to insert of LMA, complication during LMA insertion), and Hemodynamic changes. Results: The first successful attempt to insert the mask was 17 cases (85%) in the remifentanil group, 18 cases (90%) in the lidocaine group, and 15 cases (75%) in the control group (p = 0.61). The performance of the inserted mask was excellent in 70% of the remifentanil group, 80% of the lidocaine group, and 65% of the control group (P = 0.73). Mean systolic and diastolic blood pressure, heart rate, and Spo2 were not significantly different between the three groups at any time. Hemodynamic disturbances were not observed in the three groups of remifentanil (25%,), lidocaine (30%), and normal saline (20%), respectively, and there was no significant difference between the three groups (P = 0.91). Other variables, including the need for extra propofol (p = 0.53), gagging (p = 0.53), cough (p = 0.15), and laryngospasm (p = 0.99) had no significant differences in the three groups. Discussion: In the prescription of intranasal remifentanil and lidocaine, the success of laryngeal mask insertion in the first attempt, the proper functioning of the LMA, and the cardiovascular response to laryngeal mask insertion were similar among the groups. Trial registration The trial was registered at the Iranian Clinical Trials Registry registration number: IRCT20180416039326N10, date of registration:19/02/2020, available at (https://en.irct.ir/trial/43238).