Effectiveness of ultrasonic measurement for the hyomental distance and distance from skin to epiglottis in predicting difficult laryngoscopy in children

OBJECTIVES: Studies have shown that some ultrasonic indicators can predict difficult airways in adults to an extent. However, whether ultrasonic parameters can be used to predict difficult airways in children is unclear. This study investigated the predictive value of several ultrasonic indices for difficult laryngoscopy (DL) in children. METHODS: Pediatric patients aged 5 to 12 years who underwent endotracheal intubation under general anesthesia were enrolled. The hyomental distance in the extended position (HMDE), tongue thickness, midsagittal tongue cross-sectional area, tongue width, and distance from skin to epiglottis (DSE) were measured by ultrasound before anesthesia. The study end point was DL. The receiver operating characteristic curve was used to evaluate the predictive value of each parameter. RESULTS: Three hundred and ten children were included in the final analysis, and fifteen (4.8%) children had DL. The shortened HMDE assessed by ultrasound could help identify children aged 5 to 12 years with DL (5–8 years: area under the curve (AUC) 0.74, sensitivity 0.88, specificity 0.60; 9–12 years: AUC 0.72, sensitivity 0.71, specificity 0.83). An increased DSE could help identify children aged 5 to 8 years with DL (AUC 0.76, sensitivity 0.88, specificity 0.69). CONCLUSIONS: Ultrasonic measurement of the HMDE can be used to predict DL in children aged 5 to 12 years. The DSE measured by ultrasound can be used to predict DL in children aged 5 to 8 years. CLINICAL RELEVANCE STATEMENT: The hyomental distance and the distance from skin to epiglottis measured by ultrasound can be used to predict difficult laryngoscopy in children, which can help reduce serious complications caused by unanticipated difficult airways in children during anesthesia. KEY POINTS: • Ultrasonic measurement of the hyomental distance in the extended position may be an effective predictor of difficult laryngoscopy in children aged 5 to 12 years. • The distance from skin to epiglottis measured by ultrasound can be used to predict difficult laryngoscopy in children aged 5 to 8 years. • Preoperative airway assessment using ultrasound can be effectively applied in children and has a great application prospect.