Comparison of Intracuff Pressure and Postoperative Sore Throat Following Use of Laryngeal Mask Airway Protector With or Without Nitrous Oxide Anesthesia

Abstract

Purpose: In general anesthesia, the laryngeal mask airway (LMA) is a frequently used effective option. The effect of nitrous oxide on intracuff pressure of the LMA and postoperative sore throat is well known; however, there are no studies related to the second-generation LMA Protector. The purpose of this study was to determine the differences in intracuff pressure and postoperative sore throat, depending on the use of nitrous oxide during general anesthesia using the LMA Protector.

Design: This randomized double-blind prospective study was conducted among 88 patients aged 20 to 70 years.

Methods: The cuff pressure started with a baseline of 40 cm H₂O and was measured using a digital cuff pressure manometer for 30 minutes. Postoperative sore throat, dysphonia, dysphagia, and numeric rating scale scores were also recorded.

Findings: Over time, the intracuff pressure of the nitrous oxide group increased significantly compared with that of the air group. Furthermore, postoperative sore throat and pharyngolaryngeal complications were not significantly different between the two groups.

Conclusions: Intracuff pressure of the LMA Protector increased during anesthesia using nitrous oxide. When the anesthesia time was less than 2 hours, however, there was no difference in postoperative sore throat.

Keywords: laryngeal masks; postoperative complications; pressure.