Abstract
BACKGROUND AND AIMS: Supraglottic airway devices (SADs), such as the i-gel(®), are widely used during general anaesthesia but are susceptible to intraoperative displacement. Although clinical methods are commonly employed for confirming placement, they may be unreliable in identifying malposition. Video bronchoscopy (VB) is the gold standard for confirmation of proper SAD placement, but its use is limited by both cost and availability. Ultrasonography (US) is a non-invasive and cost-effective yet underutilised alternative. This study aimed to evaluate the efficacy of US in detecting I-gel(®) placement compared with VB. METHODS: In this prospective observational study, 155 female patients undergoing general anaesthesia were assessed. Pre- and post-I-gel(®) insertion glottic images were obtained using US, followed by VB to determine I-gel(®) positioning. Post I-gel(®) insertion US images were graded based on asymmetrical arytenoid cartilage elevation (0-3 scale) relative to the glottic midline and contralateral arytenoid. These grades were then correlated with VB-assessed I-gel(®) position and rotation status. RESULTS: US detected arytenoid displacement in 27% of cases. VB revealed I-gel(®) rotation in 63% and malposition in 21.9%. The sensitivity of US in detecting correctly positioned I-gel(®) was 77.69% [95% confidence interval (CI): 69.22, 84.75], with a positive predictive value (PPV) of 83.19% (95% CI: 74.99, 89.56). For identifying non-rotated I-gel(®), US showed a sensitivity of 91.07% (95% CI: 80.38, 97.04) but a lower PPV of 45.13% (95% CI: 35.75, 54.77). CONCLUSION: US is effective in detecting I-gel(®) displacement, but its ability to distinguish malposition from rotation is limited. VB remains the definitive modality for confirming accurate SAD positioning.