Distance From the Glottis to the Grille in Children

Study Overview
=================
Brief Summary
-----------------
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.

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

Conditions
-----------------
General Anesthesia

Intervention / Treatment
-----------------
* Procedure: fiberoptic bronchoscope


Participation Criteria
=================
Eligibility Criteria
-----------------
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

Ages Eligible for Study
-----------------
Maximum Age: 7 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Ambu AuraGain<br>Ambu AuraGain is inserted in children undergoing general anesthesia. The size of AuraGain is as follows: size 1 for children <5 kg, size 1.5 for 5-10kg, size 2 for 10-20kg, size 2.5 for 20-30kg. Fiberoptic bronchoscope will be performed to measure the distance between the grill and vocal cord. | Procedure: fiberoptic bronchoscope<br>* Distance from grille (the end of shaft in supraglottic airway) to glottis is measured using FOB<br>* Other names: FOB;|
| Experimental: I-gel<br>I-gel is inserted in children undergoing general anesthesia. The size of I-gel is as follows: size 1 for children weighing 2-5kg, size 1.5 for 5-12kg, size 2 for 10-25kg, size 2.5 for 25-35kg. Fiberoptic bronchoscope will be performed to measure the distance between the grill and vocal cord. | Procedure: fiberoptic bronchoscope<br>* Distance from grille (the end of shaft in supraglottic airway) to glottis is measured using FOB<br>* Other names: FOB;|
| Experimental: Air-Q intubating laryngeal airway (ILA)<br>Air-Q ILA is inserted in children undergoing general anesthesia. The size of Air-Q ILA is as follows: size 1 for children between 4-7 kg, size 1.5 for 7-17kg, size 2 for 17-30kg, size 2.5 for 30-50kg. Fiberoptic bronchoscope will be performed to measure the distance between the grill and vocal cord. | Procedure: fiberoptic bronchoscope<br>* Distance from grille (the end of shaft in supraglottic airway) to glottis is measured using FOB<br>* Other names: FOB;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The distance from grille to glottis | The distance from grille to glottis is measured using fiberoptic bronchoscopy | 30 seconds after each supraglottic airway insertion | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| FOB view | score 1: no visible glottis, score 2: visible glottis and anterior epiglottis, score 3: visible glottis and posterior epiglottis, and score 4: only glottis visible | 30 seconds after each supraglottic airway insertion | 
| Ventilation score | no air leak in airway pressure of 15 cmH2O / bilateral chest wall movement/ normal waveform of capnography | 30 seconds after each supraglottic airway insertion |