Comparison of Three Methods for the Confirmation of Laryngeal Mask Airway Placement in Female Patients Undergoing Gynecologic Surgery

The laryngeal mask airway (LMA) is a supraglottic device that is commonly used to provide lung ventilation during general anesthesia. LMA placement needs to be confirmed to provide adequate lung ventilation. To investigate the feasibility of using ultrasound examination, compared with clinical tests and fiberoptic laryngoscopy, to confirm LMA placement, we performed a clinical study of 64 female patients classified as American Society of Anesthesiologists Physical Status I or II who were scheduled for gynecologic surgery with LMA insertion for airway management. After insertion, placement of the LMA was confirmed by clinical tests, ultrasound examination and fiberoptic laryngoscopy. Of the 64 women, placement was confirmed as acceptable in 89.1% by clinical tests, in 59.4% by fiberoptic laryngoscope assessment and in 67.2% by ultrasound examination. With respect to patients with oropharyngeal leaks classified as high, there were no differences in confirmation of acceptable placement between clinical tests and ultrasound examinations (p = 0.092), but the number of patients determined to have acceptable placement by ultrasound examination was greater than that determined by fiberoptic laryngoscopy (p = 0.034). Thus, ultrasound examination is a superior technique for confirming the seal on the LMA.