Utility of ultrasound evaluation of I-Gel^® placement in children: An observational study

Background: Ultrasound is not widely used to evaluate optimal supraglottic airway positioning even though it could potentially be used to identify and correct problem areas. Aims: We evaluated a new ultrasound scoring method to identify the position of the supraglottic airway and detect the location of air leaks during ventilation in pediatric patients. Methods: Using a prospective observational study design, we enrolled 90 pediatric patients of ASA physical status I–III scheduled for elective surgery under general anesthesia. After anesthesia induction, patients were assigned to a noncorrection group or a correction group after their first ultrasound evaluation. Noncorrection group comprised patients with tolerable I-Gel positioning based on ultrasound evaluation and no problems with clinical parameters, while the correction group comprised patients with I-Gel mispositioning based on ultrasound. Results: After the first ultrasound evaluation, 61 patients did not need I-Gel correction (noncorrection group), while 29 patients needed I-Gel correction (correction group) and underwent a second ultrasound evaluation. Airway sealing pressure and total ultrasound score showed a negative correlation (r = −.845, p <.001). The area under the receiver operating curve for total ultrasound score was 0.97 (95% confidence interval, 0.94–0.99; p <.001). In the correction group, ultrasound score and ventilation parameters improved after correction based on ultrasound evaluation. Conclusions: Ultrasound scores were negatively correlated with airway sealing pressure in pediatric patients. Ultrasound evaluation is useful for detecting misplacement of the I-Gel and can be a useful tool for correction.