Usefulness of Light Wand-guided Insertion of Flexible Reinforced Laryngeal Mask Airway

Study Overview
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Brief Summary
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Flexible LMA (Laryngeal mask airway) is very useful for variable situation but it is hard to insert in correct position because of it's flexible structure. Especially in classical way of manual LMA insertion, when the index finger could not guide the flexible LMA to the optimal position, we could not guarantee the correct position of the LMA. Therefore several studies have been investigated to improve this. The light wand is a kind of stylet which have a light on the tip. Recently some studies demonstrated the usefulness of the light wand which could be used for indicating correct position of the LMA. We hypothesised there will be two advantages if the light wand is used as a stylet of the flexible LMA. First the stylet could support the mildness of the flexible LMA, and second the lightness could confirm the correct position of the flexible LMA.

Official Title
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Usefulness of Light Wand-guided Insertion of Flexible Reinforced Laryngeal Mask Airway: Comparison With Conventional Blind-insertion

Conditions
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Laryngeal Mask Airway

Intervention / Treatment
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* Device: light wand


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: The patient need general anesthesia using LMA and belonged to the ASA(American society of Anesthesiologist) class I or II Exclusion Criteria: The patient who has URI(upper respiratory infection) symptom within 14 days or The patient's BMI(body mass index) exceeds 35 kg/m2 The patient has severe GERD(gastroesophageal reflux disease) or hiatus hernia The patient who has any contraindication for LMA insertion

Ages Eligible for Study
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Minimum Age: 19 Years
Maximum Age: 75 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: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Control group<br>The flexible LMA is inserted using index finger technique | |
| Active Comparator: Light wand group<br>The flexible LMA is inserted using light wand as a stylet | Device: light wand<br>* The light wand is used as a stylet of the flexible LMA. When the investigator inserts the flexible LMA in light wand group, the correct position of the LMA is confirmed by the light.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Oropharyngeal leak pressure | The oropharyngeal leak pressure is measured by the pressure which the investigator could detect the audible sound by stethoscope on patient's cheek during the exhaust valve is closed and the fresh gas is allowed to flow into the lungs at 3 liters per minute. | 5 minutes after LMA is inserted | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The grade of oropharyngeal view through the fiberoptic assessment | The position of the LMA was assessed by fiberoptic examination through an attachment between the LMA and the anesthetic circuit. | 5 minutes after LMA is inserted |