Comparison of laryngeal mask airway (LMA) insertion with and without muscle relaxant in pediatric anesthesia; a randomized clinical trial.

Introduction: This study aimed to evaluate the effectiveness of using muscle relaxant on the ease of laryngeal mask airway (LMA) insertion and possibility of its related complications.

Methods: This double-blind, randomized clinical trial was performed on 60 children aged 1-4 years with ASA (American Society of Anesthesiology) I or II with upper limb injuries who were candidates for surgery. The patients were randomly allocated to the two groups receiving atracurium group as muscle relaxant (MR) or saline group (S).

Results: Regarding ease of placement, the LMA was inserted in 66.7% and 63.3% of patients straightforwardly in the MR and S groups, respectively. While it was performed with one maneuver in 23.3% and 26.7% of cases in the MR and S groups, respectively (p = 0.955). Moreover, LMA dislodgment in the two groups was 36.7% in the MR group and 20.0% in the S group without a meaningful difference (P = 0.152). The only complication observed in the two groups was laryngospasm, which occurred in 0.10% and 13.3% in the MR and S groups, respectively (p = 0.688).

Conclusion: In some pediatric anesthesia, the use of atracurium, as a muscle relaxant had no significant effect on capability of LMA insertion, maintaining airway patency, LMA seal pressure and oxygenation variations. Moreover, it did not have a preventive effect on the occurrence of complications such as laryngospasm.