The Role of Ultrasonography in Confirming the Position of the Laryngeal Mask Airway in Adult Patients

Abstract

Objective: The study aims to evaluate the Proseal laryngeal mask airway (PLMA) position with ultrasonographic imaging. Methods: The study included American Society of Anesthesiologists I-III patients with Mallampati scores I-II and operated using PLMA as an airway device. Before PLMA insertion, the glottic aperture was assessed by ultrasonography (USG). After PLMA placement, the USG evaluation was repeated. The symmetry of the arytenoid cartilages was examined. Asymmetry of an arytenoid to the glottic midline and the other arytenoid was graded 0 to 3 (USG arytenoid grade). After PLMA was placed, fiber optic bronchoscopy (FOB) was done to evaluate the PLMA position (FOB LMA grade). The relationship between USG arytenoid grade and FOB LMA grade was examined. Results: Forty-eight patients were included in the study. The mean age was 49 ± 15.8 (19-82), and 25 were female. It was determined that PLMA was in the correct position in 81.3% of the evaluation with USG and 68.8% of the assessment with FOB. USG arytenoid grade correlated with FOB LMA grade (r= -.582, p<.001). To detect a rotated LMA, USG had a sensitivity of 100% (%95 CI, 39.8 – 100.0) and a specificity of %80 (%95 CI, 22.8 – 99.8). The positive and negative predictive values were %97.7 (%95 CI, 88.0 – 99.9) and %100 (%95 CI, 91.8 – 100.0), respectively. The accuracy was %97.9 (%95 CI, 86.3 – 99.3). Conclusion: Ultrasonografi can be a simple, noninvasive, and reliable method to confirm PLMA placement in anesthesia practice. Keywords: Laryngeal mask airway, ultrasonography, airway management