Relationship Between Optimal Laryngeal Mask Airway Cuff Volume and Physical Examination of Head and Neck

Study Overview
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Brief Summary
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Overinflation of laryngeal mask airway cuff increase side effect like hoarseness, vocal cord paralysis, sorethroat. The investigators will study correlation between laryngeal mask airway cuff volume and pressure and physical examination of head and neck.

Detailed Description
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Overinflation of laryngeal mask airway cuff can induce side effects like hoarseness, vocal cord paralysis, sorethroat. Some study revealed that 60cmH2O of intracuff pressure is maximum pressure which is not increase side effect. The manufacturer recommends that the cuff is inflated with the minimum volume of air required to provide an effective seal(max volume - size 3, 20 ml; size 4, 30 ml; size 5, 40). The investigators will measure anatomical structure (neck circumference, neck length, thyroid-mental distance, etc.) which can influence cuff volume and pressure and find correlation between cuff volume and physical figure measured.

Official Title
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Prediction of Optimal Laryngeal Mask Airway Cuff Volume From Parameters of Physical Examination of Head and Neck

Conditions
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Anesthesia

Intervention / Treatment
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* Device: Classic laryngeal mask airway


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult (age 19-65) American Society of Anesthesiology Classification I-III Exclusion Criteria: cardiovascular disease, cerebrovascular disease, pulmonary disease patient who have operation history for airway patient who expected difficult intubation patient who have risk of aspiration

Ages Eligible for Study
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Minimum Age: 19 Years
Maximum Age: 65 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: Screening
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Classic laryngeal mask airway<br>single arm | Device: Classic laryngeal mask airway<br>* measurement of head and neck Ht,Wt,BMI, neck circumference above a thyroid cartilage, mandible circumference( from the lower part of earlobe-mandible angle-mentum-mandible angle to the lower part of earlobe), neck length (mastoid tip sternal notch), modified mallampati classification under sitting position, thyromental distance. laryngeal mask airway insertion and measuring cuff pressure by pressure transducer # 4.0 for female, #5.0 for male initial cuff volume(air) : maximum volume recommended by the manufacturer check pressure : if it exceed 60cmH20, we will remove air until 60cmH20 remove air until gas leak occured around the cuff under airway pressure 15cmH20, fresh gas flow 6liters/min. Check the volume and pressure just before leakage occured.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| optimal laryngeal mask airway cuff volume | ◦The investigators remove air until gas leak occured around the cuff under airway pressure 15cm H20, fresh gas flow 6liters/min. Check the volume and pressure just before leakage occured. | 20minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Laryngeal mask airway