The Necessity of Routine Mask Ventilation in Adults

Study Overview
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Brief Summary
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The mask ventilation is a necessary procedure to provide oxygenation before the tracheal intubation although the gastric insufflation occurs during the mask ventilation. Sugammadex, which is recently introduced, enables the use of high-dose muscle relaxant without concerning the delayed recovery of neuromuscular blockade. It seems that there is no need to perform the mask ventilation in adults with normal airway if the investigators use high-dose muscle relaxant for the anesthetic induction because adequate muscle relaxation can be achieved within 1-2 minutes. Therefore, the investigators hypothesized that routine mask ventilation is not needed in adult patients with normal airway. The investigators will compare the incidence of desaturation and gastric insufflation between the patients with mask ventilation and the patients without mask ventilation.

Conditions
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General Anesthesia

Intervention / Treatment
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* Procedure: mask ventilation
* Procedure: no mask ventilation
* Drug: Rocuronium


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: adult patients of age over 20 years for scheduled surgery with more than one and a half hours under general anesthesia Exclusion Criteria: anticipated difficult mask ventilation, anticipated difficult intubation, ASA class 3 or 4, preoperative saturation less than 92%., saturation less than 98% after preoxygenation body mass index over 35 kg/m2, obstructive sleep apnea, mass in the oral cavity or in the trachea, pregnant woman

Ages Eligible for Study
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Minimum Age: 20 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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: mask ventilation<br>Mask ventilation will be performed before the tracheal intubation. | Procedure: mask ventilation<br>* In mask ventilation group, rocuronium of 0.6 mg/kg will be administered after the loss of consciousness. Mask ventilation wil be performed until there is no response on the train-of-four stimulus. No mask ventilation - In no mask ventilation group, rocuronium of 1.2 mg/kg will be administered after the loss of consciousness. Tracheal intubation will be performed after confirmation of no response on the train-of-four stimulus. The mask ventilation will not be performed before the tracheal intubation.<br>Drug: Rocuronium<br> <br> |
| Experimental: no mask ventilation<br>Mask ventilation will not be performed before the tracheal intubation. | Procedure: no mask ventilation<br> <br> Drug: Rocuronium<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Desaturation (saturation less than 95%) | Primary outcome is the incidence of desaturation. Desaturation is defined as the saturation less than 95% which occurs after the anesthetic induction and before the first attempt of tracheal intubation. | until 2 minutes after the completion of tracheal intubation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| gastric insufflation (observe the antral area of the stomach using ultrasonography) | Secondary outcome is the antral area of the stomach. We will observe the antral area of the stomach using ultrasonography. | until 2 minutes after the completion of tracheal intubation |