Efficiency of the King Vision Video Laryngoscope

Study Overview
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Brief Summary
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The investigators studied the efficiency of Macintosh laryngoscope and the King Vision video laryngoscope in adult patients scheduled for general anesthesia. Best Cormack-Lehane score obtained, glottic view time, intubation time, time to ventilation, correlation between the Mallampati classification and the Cormack-Lehane grades, and complications related to laryngoscopy and intubation has been investigated.

Detailed Description
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Securing the airway is essential in general anesthesia. Anesthetic problems related to airway management constitute 17% of closed claims, difficult intubation being the most common one with an occurrence rate of 5%. Problems like delayed intubation, misplaced tracheal tube, or airway trauma are frequently seen in outpatient settings and end up with either death or hypoxic brain damage. Therefore, preoperative visit should include detailed assessment of the airways according to clues of difficult intubation.Several studies compared the King Vision video laryngoscope with other laryngoscopes in manikins simulating difficult airway scenarios, and reported better glottic views. The investigators aimed to study the correlation between the Mallampati classification and the glottic views (Cormack-Lehane grade) obtained with Macintosh laryngoscopy, and the King Vision video laryngoscopy in adult patients scheduled for general anesthesia. Secondary outcomes will be successful intubation rate, time to obtain the best view, time to successful intubation, and complications related to laryngoscopy will be compared.

Official Title
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Comparison of King Vision Video Laryngoscope and Macintosh Laryngoscope in Terms of First Pass Intubation Success Rate, Intubation Time, Glottic View Time, and Complications Related to Laryngoscopy

Conditions
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Respiratory Failure, Intubation

Intervention / Treatment
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* Device: Macintosh laryngoscope
* Device: King Vision video laryngoscope


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: scheduled for general anesthesia age higher than 18 years age lower than 60 years Exclusion Criteria: emergency surgery mouth opening less than 2 cm American Society of Anesthesiologists (ASA) score higher than 2 oropharyngeal anomaly glottic or supraglottic mass history of surgery due to oropharyngeal anomaly, glottic or supraglottic mass

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Sequential Assignment
Interventional Model Description: Patients scheduled for general anesthesia with endotracheal intubation will be randomized to either intubation with Macintosh laryngoscope first or King Vision videolaryngoscope first. All patients will be intubated with both laryngoscopes.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Macintosh<br>Patients scheduled for general anesthesia during the study period, who had been intubated with Macintosh laryngoscope first and then with KingVision videolaryngoscope. | Device: Macintosh laryngoscope<br>* Using a Macintosh laryngoscope, time to glottic view, best Cormack-Lehane grade, time to intubation, time to first ventilation has been recorded.<br>Device: King Vision video laryngoscope<br>* Using a King Vision video laryngoscope, time to glottic view, best Cormack-Lehane grade, time to intubation, time to first ventilation has been recorded.<br>|
| Active Comparator: KingVision<br>Patients scheduled for general anesthesia during the study period, who had been intubated with King Vision videolaryngoscope first and then with Macintosh laryngoscope. | Device: Macintosh laryngoscope<br>* Using a Macintosh laryngoscope, time to glottic view, best Cormack-Lehane grade, time to intubation, time to first ventilation has been recorded.<br>Device: King Vision video laryngoscope<br>* Using a King Vision video laryngoscope, time to glottic view, best Cormack-Lehane grade, time to intubation, time to first ventilation has been recorded.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intubation Success Rate | Endotracheal intubation attempt is defined as entrance of the endotracheal tube into the patient's mouth. Any major change in the alignment of the laryngoscope is defined as another intubation attempt. Successful endotracheal intubation is defined as the endotracheal cuff passing through the patient's vocal cords. Intubation success rate is defined as: 1 / [the number of attempts]. | less than 24 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intubation Time | Successful endotracheal intubation is defined as the endotracheal cuff passing the patient's vocal cords. Time to intubation with each laryngoscope is recorded. | less than 24 hours | 
| Glottic View Time | Glottic view time (as defined when the laryngoscopist declared the best Cormack-Lehane score) with each laryngoscope is recorded. Cormack-Lehane score is obtained by directly assessing the distance between the base of the tongue and the roof of the mouth to predict how difficult an intubation will be. It consists of 4 grades: full view of glottis (difficult intubation unlikely) partial view of glottis ( 5% risk of difficult intubation) partial view of epiglottis, none of glottis seen ( 90% risk of difficult intubation) neither glottis nor epiglottis seen (difficult intubation very likely) | less than 24 hours | 
| Cormack-Lehane Score | Best Cormack-Lehane score (as declared by the laryngoscopist) obtained with both laryngoscopes is recorded. Cormack-Lehane score is graded according to the following criteria (1 is best, and 4 is worst): full view of glottis (difficult intubation unlikely) partial view of glottis ( 5% risk of difficult intubation) partial view of epiglottis, none of glottis seen ( 90% risk of difficult intubation) neither glottis nor epiglottis seen (difficult intubation very likely) | less than 24 hours | 
| Airway Complications | Any complication related to the laryngoscopy and intubation, such as cut, bleeding, damage to the teeth, laryngospasm, bronchospasm, desaturation below 90%, is recorded. | The participants' will be followed for the duration of hospital stay, an expected average of 2 days |