Comparison of the Video and Macintosh Laryngoscope in Patients Who May be Difficult to Intubate

Study Overview
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Brief Summary
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The purpose of this study is to determine if the Video Laryngoscope (VL) is a useful instrument in patients at risk for difficult intubation. We will compare this device to the traditional Macintosh Laryngoscope.

Detailed Description
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Despite improvements made to the traditional laryngoscope blade since its invention, occasionally intubation of the trachea cannot be accomplished with facility, even in patients with anatomy that does not predict difficult intubation. It is estimated that endotracheal intubation is performed on some 8 million patients per year in the United States. Of these endotracheal intubations, approximately 80% are performed by direct laryngoscopy with transoral placement of the endotracheal tube (ET) into the trachea. There is fairly uniform reporting of the incidence of failed intubation in the literature; it occurs in approximately 0.05% or 1:2230 of surgical patients and in approximately 0.13% to 0.35%, or 1:750 to 1:280, of the obstetric patients. The incidence of unsuspected difficult intubation is estimated to be higher at 3%. One factor that contributes to difficult intubation is poor visualization. The VL is designed to optimize visualization by presenting to the operator an enlarged video image of airway structures. In contrast, using conventional laryngoscopy, anesthesiologists have only a keyhole view of the airway structures; a view that may be further obscured during attempts to pass the ET. The VL consists of a laryngoscope handle and Macintosh blade that have been modified to provide a video image of airway structures on a screen, which can be conveniently located directly in front of the anesthesiologist. A micro video module is contained in the modified handle. An image/light bundle is introduced into the standard blade. This system has been previously tested in which the consensus was that the device is extremely easy to learn to use because most anesthesiologists are familiar with the use of the Macintosh blade. It has also been useful in the instruction of laryngoscopy by non-anesthesiologists. There are several potential advantages of a video image in the context of direct laryngoscopy. The system provides high quality video images that are enlarged on the video monitor for easier visualization. If laryngeal manipulation is required to improve visualization of laryngeal structures, the intubator and the person assisting can coordinate movements as they observe, simultaneously, the image on the video monitor. With the video image projected from the distal end of the laryngoscope blade, laryngeal structures are kept in view as the ET is passed through the oropharynx into the trachea. Comparison: Video Laryngoscope as a conduit for possible difficult intubation compared to the traditional Macintosh blade.

Official Title
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A Comparison of Laryngoscopy Techniques Using the Video Laryngoscope and the Traditional Macintosh Laryngoscope in Patients Who May be Difficult to Intubate

Conditions
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Intubation, Endotracheal

Intervention / Treatment
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* Device: DCI Video Intubation System-Macintosh Laryngoscope
* Device: Macintosh Laryngoscope


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 18-80 ASA I-III Presenting for elective surgery Requires general anesthesia Present as a possible difficult intubation (one or more of the following) history of difficult intubations morbid obesity small mouth opening (<3 fingerbreadths) limited neck mobility Mallampati classes II-III short thyromental distance (<6 cm) Exclusion Criteria: Determined to be easily intubated (none of the factors listed above) Considered so difficult (i.e. Mallampati IV) that an awake intubation should be performed ASA IV and V

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Design Details

Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Intervention/Treatment |
| --- |
|Device: DCI Video Intubation System-Macintosh Laryngoscope|nan|
|Device: Macintosh Laryngoscope|nan|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 5 scale score of glottic view; Time and number of attempts required; Level of difficulty; Degree of irritation of the pharynx, epiglottis, and aryteniods |  |  | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Vital signs, oxygen saturation, and end-tidal carbon dioxide |  |  | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Endotracheal Intubation, Video Laryngoscopy