Comparison of confirmation of placement of laryngeal mask airway by fiberoptic laryngoscope and ultrasound examination: A feasibility study

Background: The laryngeal mask airway (LMA) is widely used as an effective and safe airway adjunct in the routine practice of anesthesia. There are various methods to assess the correct placement, the gold standard being fiberoptic visualization through the LMA. Ultrasound (USG) is a noninvasive, readily available diagnostic tool and has been used with increased frequency for airway examination. The aim of our study was comparison of fiberoptic and USG evaluation for the confirmation of placement of LMA. Patients and Methods: This was a cross-sectional observational study conducted on 250 patients of American Society of Anesthesiologists Grade 1 and 2, in the age group of 18–65 years undergoing elective surgery under general anesthesia with LMA. The position of the LMA cuff was confirmed by USG and reconfirmed with fiberoptic laryngoscopy (FOL). Results: We observed that the USG Grade 1 was seen in 76.8% of patients as compared to FOL Grade 1 seen in 81.6%. The frequency of LMA misplacement (i.e., Grades 2–4) noted with USG was 23.2% and with FOL was 18.4%. The Bland–Altman scatter plot showed insignificant differences between the two grading systems (near-zero mean: 0.05), with small limits of agreement (−0.509 to +0.609). Conclusion: USG can replace fiberoptic examination for confirmation of the correct placement of an LMA. USG can further give insight into the grading of LMA placement and the cause of airway and ventilation events, which can be corrected and prevented