Distance From the Glottis to the Grille in Children

Distance From the Glottis to the Grille in Children: Ambu AuraGainTM , I-gel, Air-Q Intubating Laryngeal Airway as Intubation Conduits

Ambu AuraGain, I-gel, Air-Q intubating laryngeal airway are the most commonly used supraglottic airway. In children, they can be used as intubation conduits. However, there has been no guideline for optimal insertion depth of endotracheal tube through those supraglottic airway. In this study, the investigators will measure the distance from grille of those supraglottic airways to glottis using fiberoptic bronchoscope in children undergoing anesthesia. This distance allows us to predict an appropriate depth of endotracheal tube when it should be inserted through each supraglottic airway.

Inclusion Criteria:

• children < 7 years old undergoing elective surgery

Exclusion Criteria:

• difficult airway
• BMI> 30kg/m2
• emergency operation
• cervical spine disease
• history of esophageal disease and surgery