The GlideScope Video Laryngoscope (GVL) is an extremely useful tool for managing challenging intubations, but it can be more difficult to use if your patient has a small mouth and a high arched, narrow palate. The problem: once the GlideScope is in place in a small mouth, maneuvering the endotracheal tube around it and into the posterior pharynx can be challenging. If you can pass the endotracheal tube (ETT) at all, the cuff tends to scrape against the teeth, risking rupture. However, there is a modified GlideScope technique you can use in those situations.
Standard GlidesScope Technique
Let’s start by quickly reviewing the standard GlideScope technique.
Insert The Blade Midline
You must insert the blade midline, not to the right side of the mouth like a MAC blade. You are not going to sweep the tongue. The GVL works best if the blade’s camera is aimed straight at the glottic opening. In addition, if the mouth is small, having the blade on the right with definitely block your tube.
Don’t Insert The Blade Too Deeply
One of the most common errors is to insert the GVL as deeply as you possibly can placing the very tip of the GlideScope blade on the anterior commissure of the vocal cords like a MAC blade. You will have a superb view of the larynx but due to the short focal length of the lens, the tip is a lot closer to the larynx than you think. This position places the glottis very high in your field of view and you won’t have either the optimal angle or the maneuvering room to manipulate the tip of the ETT into the larynx.
Instead, pull the blade back a bit and insert its tip behind the epiglottis into the vallecula. This gives you room to maneuver the ETT.
Insert the Endotracheal Tube
Once the blade is positioned with the larynx in view, insert the ETT along the right side of the blade. Rather than insert the ETT facing forward, instead insert it with the curve aimed toward the right side of the mouth, or 3:00 o’clock position. Once you start to see the tip on the monitor, rotate the tube tip back toward the midline (12 o’clock position) and aim it at the larynx. The advantage of this approach is that the tip of the ETT avoids bumping into the GlideScope blade on the way into the mouth.
Look at the mouth while inserting the tube. Only after the tip of the ETT has turned the corner into the pharynx and passed the tonsillar pillars should you look at the monitor — otherwise you can injure teeth, lips, tongue and pharyngeal structures.
Manipulate the tip of the tube through the glottis, then pause to withdraw the stylet slightly to effectively soften the tip of the ETT. Advance the ETT into the trachea looking at the monitor. Remove the GlideScope blade looking at the patient, not the monitor.
Don’t Insert The ETT Tip Too Posteriorly
Inserting the endotracheal tube tip too posteriorly into the back of the pharynx is another common error. If the ETT drops deep into the throat, touching the posterior pharyngeal wall, then the tip of the ETT is in the wrong plane. As it rotates forward toward the glottis it tends to hit the back of the arytenoids. This leads to the frustration of seeing the larynx clearly and simply not being able to insert the ETT.
Instead, in order to place the glottis within the arc of the styleted ETT, I recommend positioning the tip of the ETT in the upper right hand corner of the monitor. This places the ETT tip in the upper part of the pharynx. The curving path from this position usually places the tip in the correct plane for entering the glottis.
The illustration on the left show the ETT too far posterior, and therefore in the wrong plane of rotation. On the right the tube has been pulled back, placing it higher and further from the posterior pharyngeal way, and in the correct arc of insertion.
Don’t Forget To Lift The Jaw
Providers have such a great view of the larynx, they forget that they still have to create an open path for the ETT to successfully enter the larynx. You may (or may not) have to lift the jaw or the patient’s head upward.
Modified For Narrow, Small Mouths
If the mouth is small and narrow there is often no room to pass the ETT once the blade is in place. A struggle to insert ensues, with the cuff often catching on the teeth where it may rip.
When faced with this problem, remove the blade and ventilate the patient. On your next attempt, slide the ETT into the mouth first, with the tip turned 90 degrees to the right, the 3 o’clock position. Hold it to the far right. You want the ETT tip inside the teeth, NOT outside the teeth against the cheek. You can ask your assistant to hold it for you, to free you to use both hands if desired.
With the ETT tip in the posterior pharynx and the tube held far to the right side, insert the GlideScope blade midline and rotate it into position. Visualize the larynx.
At this point, grasp the ETT and simply rotate the ETT tip, which is already in the posterior pharynx, back to the 12 o’clock position. Pass it into the trachea.
While not foolproof, this GlideScope technique is extremely helpful. I’ve used it three times already just this week. for additional discussion on how to use the GlideScope see here.
May The Force Be With You
Christine Whitten MD
author Anyone Can Intubate: A Step-by-Step Guide and Pediatric Airway Management: A Step-by-Step Guide
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