The Influence of Head and Neck Position on Performance of Ambu AuraGain™

Study Overview
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Brief Summary
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The influence of different head and neck positions on the effectiveness of ventilation with the Ambu AuraGain airway remains unevaluated. This study aimed to evaluate the influence of different head and neck positions on ventilation with the AuraGain airway. AuraGain will be placed in all patients, and mechanical ventilation will be performed using a volume-controlled mode with a tidal volume of 10 ml/kg. The expiratory tidal volume, peak inspiratory pressure, oropharyngeal leak pressure, and ventilation score will be assessed first for the neutral head position and then for the extended, flexed, and rotated head positions in a random order. Fiberoptic bronchoscopic view will be also assessed for each head and neck positions.

Official Title
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The Influence of Head and Neck Position on Performance of Ambu AuraGain™

Conditions
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General Anesthesia

Intervention / Treatment
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* Procedure: Flexion
* Procedure: Extension
* Procedure: Right rotation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adults who were to undergo elective surgery under general anaesthesia using supraglottic airway device Exclusion Criteria: Patients who had risk factor for difficult intubation BMI > 30kg/m2 Emergency operation without NPO History of cervical spine surgery or disease History of esophageal operation or gastroesophageal reflux disease

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: AuraGain will be placed in all patients, and mechanical ventilation will be performed using a volume-controlled mode with a tidal volume of 10 ml/kg. The expiratory tidal volume, peak inspiratory pressure, oropharyngeal leak pressure, and ventilation score will be assessed first for the neutral head position and then for the extended, flexed, and rotated head positions in a random order. Fiberoptic bronchoscopic view will be also assessed for each head and neck positions.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Neutral<br>After insertion of Ambu AuraGain™, the variables will be assessed at each positions including neutral, flexion, extension, right rotation under random order. | |
| Experimental: Flexion<br>After positioning the subjects' neck to flexion, the variables will be assessed. | Procedure: Flexion<br>* After changing the position of head and neck of subjects to flexion, the variables were measured.<br>|
| Experimental: Extension<br>After positioning the subjects' neck to extension, the variables will be assessed. | Procedure: Extension<br>* After changing the position of head and neck of subjects to extension, the variables were measured.<br>|
| Experimental: Right rotation<br>After positioning the subjects' head to right rotation, the variables will be assessed. | Procedure: Right rotation<br>* After changing the position of head and neck of subjects to right flexion, the variables were measured.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Oropharyngeal leak pressure | The airway pressure at which a leak sound is detected around the patient's mouth and at which the airway pressure has reached equilibrium, when the pressure-limiting valve of the anesthesia breathing system is closed and the fresh gas flow rate was fixed at 3 L/min. | 30 seconds after positioning of head and neck | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Peak inspiratory pressure | Peak inspiratory pressure | 30 seconds after positioning of head and neck | 
| Expiratory tidal volume | Expiratory tidal volume | 30 seconds after positioning of head and neck | 
| Ventilation score | No leakage with an airway pressure of 15cmH2O; bilateral chest excursion with a peak inspiratory pressure of 20cmH2O; and a square-wave capnogram | 30 seconds after positioning of head and neck | 
| Fiberoptic score | 1, vocal cords not visible; 2, vocal cords plus anterior epiglottis visible; 3, vocal cords plus posterior epiglottis visible; 4, only vocal cords visible | 30 seconds after positioning of head and neck |