Evaluation of Four Techniques to Administer Laryngeal Mask Airway.

Abstract

Background: Laryngeal mask airway (LMA) plays a crucial role in the field of modern anesthesia. There are different techniques to administer LMA. Here we aimed to compare the four methods of standard, 90° rotation, 180° rotation, and thumb placement in LMA mast placement.

Materials and methods: This is a clinical trial that was performed on 257 candidates of elective surgical operations requiring general anesthesia. All patients were categorized into four groups of LMA placement with index finger (standard method), mask placement with 90° rotation, 180° rotation method, and thumb finger group. We collected data regarding the success rates of LMA placement, the need for any manipulation when placing the mask, LMA placement time, failure of mask placement, presence of blood on the LMA, and laryngospasm and sore throats 1 hour after surgery in patients.

Results: The 90° rotation method had a significantly higher first attempt success rate than that in the other three methods (98.4%, P = 0.02). Total success rate in 90° rotation method was also significantly higher than the other techniques (100%, P < 0.001). The need for any manipulation when placing the mask (1.6%, P = 0.01), presence of blood on the LMA mask (1.6%, P = 0.33), and frequency of sore throats 1 hour after surgery (21.9%, P = 0.14) were also lower in 90° rotation method than that in the other methods.

Conclusion: The 90° rotation method had significantly higher success rate and lower failure rate regarding the mask placement compared to other three methods.