Effect of Different Insertion Methods on LMA Protector-Related Complications: A Prospective Randomized Double-Blind Clinical Trail

Abstract

Objective: The authors compared the effect of 2 insertion methods, namely the conventional laryngeal mask airway (LMA) insertion and the index finger–assisted LMA insertion, on the incidence of complications associated with LMA Protector insertion. Methods: The authors enrolled 300 patients, who underwent painless bronchoscopy. The patients ranged in age between 18 and 75 and were classified as American Society of Anesthesiologists grade I to III. They were randomly divided into 2 groups: a control group of 150 patients and an assisted group comprising 150 patients. LMA was inserted using the conventional and index finger–assisted insertion methods in both groups, respectively. The primary outcome was postoperative complications, such as oral mucosal injury and pharyngeal pain. Secondary outcomes included the success rate of first-time insertion, the incidence rate of inverse folding of LMA tips, oropharyngeal leak pressure (OLP), and other postoperative complications. Results: Compared with the conventional LMA insertion method, index finger–assisted LMA insertion can significantly reduce the incidence rate of oral mucosal injury and pharyngeal pain, with fewer insertion failures. There was a statistically significant difference between the 2 groups in the visual field grading before adjustment for LMA alignment (P<0.0001). The conventional insertion method increased the likelihood of inverse folding of LMA tips. When the conventional insertion method was utilized, there was a significant difference in airway pressure and tidal volume before and after alignment under a fiberoptic bronchoscope (P<0.0001), but no significant difference in visual field grading and respiratory mechanics-related indicators. Conclusions: Index finger–assisted insertion can significantly reduce the incidence rate of LMA Protector-related complications and inverse folding of LMA tips.