Improvement of the Glottic View by Video Laryngoscope

Study Overview
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Brief Summary
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This study aims to compare the exposure of glottis by the use of video and direct laryngoscopy.

Detailed Description
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It is well known that a video laryngoscope can provide better glottic view than a direct laryngoscope. However, to date, a direct laryngoscope has been the standard equipment for tracheal intubation. Recently, it seems that use of the video laryngoscope has increased. However, the advantage of the video laryngoscope over a direct laryngoscope has not been measured quantitatively. In this study, the glottic view by the use of video laryngoscope will be compared with that of the direct laryngoscope simultaneously, by using C-MAC S-imager installed with a disposable Macintosh blade. Intubating anesthesiologists will use it as if it is a direct laryngoscope. Simultaneously, the glottic views visualized on the monitor of the video laryngoscope will be recorded and evaluated later. For quantitative comparison, the glottic view will be scored with the Percentage of glottic opening scale, for both direct laryngoscopy and video laryngoscopy. Also, the glottic view will be compared by Cormack-Lehane grade.

Official Title
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Improvement of the Glottic View by the Use of Video Laryngoscope

Conditions
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Laryngoscope, Intubation, Laryngoscopy

Intervention / Treatment
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* Device: Video laryngoscopic view
* Device: Direct laryngoscopic view


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients who are over 18 years old, and are planning surgeries that require general anesthesia and tracheal intubation. Exclusion Criteria: Patients who are not agreed to participate in the trial Patients who have a poor dental condition which requires other than direct laryngoscopy Patients who require rapid sequence induction technique Patients with cervical spine instability

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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| patient<br>39 patients who are planning surgeries that require general anesthesia and tracheal intubation | Device: Video laryngoscopic view<br>* The glottic view on the screen of the video laryngoscope during laryngoscopy with a C-MAC video laryngoscope, which installed with Macintosh blade.<br>Device: Direct laryngoscopic view<br>* The glottic view evaluated by the anesthesiologist who performing tracheal intubation, by direct laryngoscopy with C-MAC installed with Macintosh blade.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| POGO (Percentage of Glottic Opening) score | POGO (Percentage of Glottic Opening) score of the glottic view by video/direct laryngoscope during laryngoscopy without external laryngeal manipulation. (Percentage of glottic opening score, which means a better outcome at higher score: linear span from the anterior commissure to the interarytenoid notch; 0%, only interarytenoid notch seen; 100% full view of vocal cords) | during laryngoscopy | 
| Cormack-Lehane grade | Cormack-Lehane grade with video/direct laryngoscope, during laryngoscopy without external laryngeal manipulation (Cormack-Lehane grade, which means a better outcome at lower score: grade 1, Full view of glottis; grade 2a, Partial view of glottis; grade 2b, Only posterior extremity of glottis or arytenoid cartilages; grade 3, Only epiglottis seen; grade 4, Neither glottis nor epiglottis seen) | during laryngoscopy | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| POGO score with external laryngeal manipulation | POGO score of the glottic view by video/direct laryngoscope during laryngoscopy with external laryngeal manipulation. (Percentage of glottic opening score, which means a better outcome at higher score: linear span from the anterior commissure to the interarytenoid notch; 0%, only interarytenoid notch seen; 100% full view of vocal cords) | during laryngoscopy | 
| Cormack-Lehane grade with external laryngeal manipulation | Cormack-Lehane grade with video/direct laryngoscope, during laryngoscopy with external laryngeal manipulation. (Cormack-Lehane grade, which means a better outcome at lower score: grade 1, Full view of glottis; grade 2a, Partial view of glottis; grade 2b, Only posterior extremity of glottis or arytenoid cartilages; grade 3, Only epiglottis seen; grade 4, Neither glottis nor epiglottis seen) | during laryngoscopy | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Video laryngoscope, Glottis, Airway