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A Novel Special-shaped Stylet Technique for Intubation with GlideScope® Video Laryngoscope Devices

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Abstract

The GlideScope® video laryngoscope (VL) provides direct visualization of the larynx in patients with a potentially difficult airway. A specialized rigid stylet or tracheal introducer should be used to guide the tip of the endotracheal tube (ETT) into the glottis while using the GlideScope® devices. Several studies showed the success of the GlideScope® VL. However, there have been reports of problems, complications, including failure to intubate patients successfully. Laryngeal exposure is generally the simple part of the procedure, and conversely, tube delivery to the glottic opening and advancement into the trachea is sometimes not straightforward. Alekberli-Yarmush technique: Our novel technique for improving the GlideScope® intubation's success requires preparation of the stylet and ETT before the intubation. Requirements are the following: any brand and model shapable ETT stylet, ETT, and lubricant. Firstly, lubricate the stylet with a lubricant, insert the stylet into ETT, and bend the stylet into a unique shape. Firstly bend the ETT into the two-dimensional circular C shape, then bend the tip again two-dimensionally, approximately 100-110° against the circular angle. For the final step, bend the tip toward the 3rd dimension medially, proximally 45°. Endotracheal tube insertion is usually performed in our method, as the manufacturer recommends a four-step insertion technique when using the GlideScope®. However, holding the tube with two fingers, palm up, 2/3 of the way down the tube toward the tip, is different from the traditional technique. To intubate using our novel technique, first, the GlideScope® should be introduced into the oropharynx's midline with the left hand. When the epiglottis is identified on the screen, the scope should be manipulated, and the tip of the blade should be put in vollecula and elevate the epiglottis to obtain the best view of the glottis. The ETT should then be guided into position under direct vision. The ETT should be hugging the undersurface of the tongue. When the distal tip of the ETT disappears from the direct view, it should be viewed on the monitor. In this time, rotation and angulation maneuvers are not required in our technique different than the traditional technique to direct the ETT through the glottis. After visualizing the successful intubation, a stylet should be pulled out to remove easily from the ETT. The unique shape of the novel technique described here can improve the GlideScope® intubation by decreasing the manipulation, rotation, and angulation maneuvers. Due to the medially 45° shaped tip of the ETT, the intubation may be smoother and more comfortable. The ETT's C type circular shape allows it to hug the tongue's undersurface and slide quickly and smoothly to the laryngeal space. Studies with larger patient populations are needed to determine if the new technique improves the GlideScope® intubation, better understand the mechanisms and the clinical significance, and ascertain whether this technique evolves into a useful technique.
CLINICAL TECHNIQUE
A Novel Special-shaped Stylet Technique for Intubation with
GlideScope® Video Laryngoscope Devices
Tural Alekberli1, Leslie Yarmush2
AbstrAct
The GlideScope® video laryngoscope (VL) provides direct visualization of the larynx in patients with a potentially dicult airway. A specialized
rigid stylet or tracheal introducer should be used to guide the tip of the endotracheal tube (ETT) into the glottis while using the GlideScope®
devices. Several studies showed the success of the GlideScope® VL. However, there have been reports of problems, complications, including failure
to intubate patients successfully. Laryngeal exposure is generally the simple part of the procedure, and conversely, tube delivery to the glottic
opening and advancement into the trachea is sometimes not straightforward. Alekberli-Yarmush technique: Our novel technique for improving
the GlideScope® intubation’s success requires preparation of the stylet and ETT before the intubation. Requirements are the following: any brand
and model shapable ETT stylet, ETT, and lubricant. Firstly, lubricate the stylet with a lubricant, insert the stylet into ETT, and bend the stylet
into a unique shape. Firstly bend the ETT into the two-dimensional circular C shape, then bend the tip again two-dimensionally, approximately
100–110° against the circular angle. For the nal step, bend the tip toward the 3rd dimension medially, proximally 45°. Endotracheal tube
insertion is usually performed in our method, as the manufacturer recommends a four-step insertion technique when using the GlideScope®.
However, holding the tube with two ngers, palm up, 2/3 of the way down the tube toward the tip, is dierent from the traditional technique.
To intubate using our novel technique, rst, the GlideScope® should be introduced into the oropharynx’s midline with the left hand. When
the epiglottis is identied on the screen, the scope should be manipulated, and the tip of the blade should be put in vollecula and elevate the
epiglottis to obtain the best view of the glottis. The ETT should then be guided into position under direct vision. The ETT should be hugging
the undersurface of the tongue. When the distal tip of the ETT disappears from the direct view, it should be viewed on the monitor. In this time,
rotation and angulation maneuvers are not required in our technique dierent than the traditional technique to direct the ETT through the
glottis. After visualizing the successful intubation, a stylet should be pulled out to remove easily from the ETT. The unique shape of the novel
technique described here can improve the GlideScope® intubation by decreasing the manipulation, rotation, and angulation maneuvers. Due
to the medially 45° shaped tip of the ETT, the intubation may be smoother and more comfortable. The ETT’s C type circular shape allows it to
hug the tongue’s undersurface and slide quickly and smoothly to the laryngeal space. Studies with larger patient populations are needed to
determine if the new technique improves the GlideScope® intubation, better understand the mechanisms and the clinical signicance, and
ascertain whether this technique evolves into a useful technique.
Keywords: Airway, Dicult intubation, Glidescope, Laryngoscope, Videolaryngoscope.
Research and Innovation in Anesthesia (2021): 10.5005/jp-journals-10049-0108
IntroductIon
The video laryngoscope (VL) is a device that allows indirect
laryngoscopy, or visualization of the vocal cords and related
airway structures without a direct line of sight, and it is used
to facilitate endotracheal intubation in cases of a suspected or
unexpected dicult airway.1 With an improved laryngeal view,
video lary ngoscopy can facilitate better endotracheal intubatio n.2,3
Compared with conventional direct laryngoscopy (DL), video-
assisted indirect laryngoscopy improves tracheal intubation’s
rst-attempt success rates and decreases intubation diculty.4–6
Furthermore, in the unexpected dicult airway scenario, VLs oer
a useful rescue technique fo r failed DL intubation.7,8 Consequently,
video laryngoscopy is now widely used to manage both expected
and unexpec ted dicult endotracheal intubations in anesthetize d
patients.
An acute-angle VL blade allows better visualization of anterior
laryngeal structures than a more gently curved blade. Examples
of devices with acute-angle blades include several GlideScope®
products (Fig. 1) (Titanium, AVL and Spectrum, GlideScope® Go,
Verathon Medical). The GlideScope® blade is oriented upward at
a 60° angle, with the recessed wide-angle CMOS camera located
one-third of the way from the blade’s distal tip. The GlideScope®
VL provides direct visualization of the larynx in patients with a
potentially dicult airway. A specialized rigid stylet or tracheal
introducer should be used to guide the tip of the endotracheal
tube (ETT) into the glottis while using the GlideScope® devices.
The use of these devices without an introducer is contrary to the
manufacturers’ recommendations and may require repeated
attempts at laryngoscopy.9 The GlideRite® stylet (Fig. 2) (GRS;
Verathon Medical) is placed into the ETT to help direct the ETT
through the glottic opening.10,11 Several studies showed the
success of the GlideScope® VL.12–15 However, there have been
reports of complications, including failure to successfully intubate
1,2Department of Anesthesiology, Critical Care and Pain Medicine,
Hadassah Medical Center, The Hebrew University, Jerusalem, Israel
Corresponding Author: Tural Alekberli, Department of Anesthesiology,
Critical Care and Pain Medicine, Hadassah Medical Center, The
Hebrew University, Jerusalem, Israel, Phone: +972 504048435, e-mail:
turalalek@gmail.com
How to cite this article: Alekberli T, Yarmush L. A Novel Special-shaped
Stylet Technique for Intubation with GlideScope® Video Laryngoscope
Devices. Res Inno in Anesth 2021;XX(X):1–4.
Source of support: Nil
Conict of interest: None
© Jaypee Brothers Medical Publishers. 2021 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License
(https://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted use, distribution, and non-commercial reproduction in any medium, provided you give
appropriate credit to the o riginal author(s) and the source, provide a link to the Creati ve Commons license, and indicate if changes were m ade. The Creative Commons
Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
A Novel Special-shaped Stylet Technique for Intubation with GlideScope® VL Devices
Research and Innovaon in Anesthesia, Volume x Issue x (XXX 2021)
2
Figs 1A to F: GlideScope® products. (A) GlideScope® screen; (B) AVL
single-use blade; (C) AVL video camera and light source cable; (D)
GlideScope® Go; (E) Titanium re-usable blades; (F) Spectrum single-use
blades
Figs 2A and B: The GlideRite® specialized rigid stylet for GlideScope®
intubation. (A) GlideRite® specialized rigid stylet; (B) Tube insertion
with GlideRite®
Figs 3A to F: Steps (timeline A–F) of preparation of the unique shaped ETT with Alekberli-Yarmush technique
A Novel Special-shaped Stylet Technique for Intubation with GlideScope® VL Devices
Research and Innovaon in Anesthesia, Volume x Issue x (XXX 2021) 3
patients.16–19 With these devices, la ryngeal exposure is generall y the
simple part of the procedure, and conversely, tube delivery to the
glottic opening and advancement into the trachea is sometimes
not straightforward.20 We describe a novel method using a
special-shaped stylet to increase intubation success by using the
GlideScope® VL devices.
descrIptIon of the novel Methods
Alekberli-Yarmush Technique
Our novel technique for improving the GlideScope® intubation’s
success requires preparation of the stylet and ETT before the
intubation. Requirements are the following; any brand and model
shapable ETT stylet (a device that allows the ETT to be stiened
and the shape molded as desire d), ETT, and water-soluble lubricant.
Preparation of the Stylet
Lubricate stylet with a water-soluble gel, insert the stylet into ETT
(Fig. 3A), and bend the stylet into the unique s hape. Firstly bend the
ETT into the two-dimensional circular C shape (Fig. 3B), then bend
the tip again two-dimensionally, approximately 100–110° against
the circular angle (Fig. 3C). For the nal step, bend the tip toward
the 3rd dimension medially proximall y 45° (Fig. 3D). The nal version
of the special-shaped ETT showed in Figures 3D to F.
Endotracheal tube insertion is usually performed in our
method, as the manufacturer recommends a four-step insertion
technique while using the GlideScop e®. However, holding the tube
with two ngers, palm up, 2/3 of the way down the tube toward
the tip, is dierent from the traditional technique.
First, the GlideScope® sho uld be introduced into the midline of
the orophary nx with the left hand. When the epigl ottis is identied
on the screen, the scope should be manipulated, and the tip of
the blade should be put in vollecula and elevate the epiglottis to
obtain the best view of the glottis (Fig. 4A). The ETT should then
be guided into position under direct vision. The ETT should be
hugging the undersur face of the tongue. When the distal tip of the
ETT disappears from the direct view, it should be viewed on the
monitor (Fig. 4B). In this time, rotation and angulation maneuvers
are not required in our technique dierent than the traditional
technique to direct the ETT through the glottis (Figs 4C to F). After
visualizing the successful intubation, a stylet should be pulled out
to remove easily from the ETT.
dIscussIon And conclu s I o n
Video laryngoscope devices can provide remarkably easy laryngeal
exposure due to the video c amera’s positioning and location. These
devices are transforming airway management in many respects,
both in dicult airway management and education. Although
Figs 4A to F: GlideScope® monitor views (timeline A–F) while intubating using the new Alekberli-Yarmush technique (special-shaped stylet technique)
A Novel Special-shaped Stylet Technique for Intubation with GlideScope® VL Devices
Research and Innovaon in Anesthesia, Volume x Issue x (XXX 2021)
4
they bypass DL mechanics, all alternative devices create dierent
potential challenges in get ting the tube to the glottic opening and
advancing the tube into the trachea. Acute-angled, unchanneled
VLs like GlideScope® usually require st ylets to aid tube delivery, but
the stylet mus t be partially withdrawn to permit tube adv ancement.
Tube rotation, use of a tube introducer, or using specialized ETTs
may also help with tube advancement. However, the special rigid
stylet (Gliderite®) does not guarantee the success of intubation. In
this regard, new and more unique shap es of the stylets may increase
the success rate. The unique shape of the novel Alekberli-Yarmush
technique described here (Fig. 3) may improve the GlideScope®
intubation by decreasing the manipulation, rotation, and angulation
maneuvers. Due to the medially 45° shaped tip of the ETT, the
intubation may be smoother and more comfortable. The ETT’s C
type circular shape allows it to hug the tongue’s undersurface (Fig.
3) and slide quickly and smoothly to the laryngeal space.
Studies with large patient populatio ns are needed to determine
if the new technique is improving the GlideScope® intubation,
better understand the mechanisms and the clinical signicance,
and ascertain wheth er this technique evolves into a useful method.
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Article
Full-text available
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The Glidescope video laryngoscope has been shown to be a useful tool to improve laryngeal view. However, its role in the daily routine of airway management remains poorly characterized. This investigation evaluated the use of the Glidescope at two academic medical centers. Electronic records from 71,570 intubations were reviewed, and 2,004 cases were identified where the Glidescope was used for airway management. We analyzed the success rate of Glidescope intubation in various intubation scenarios. In addition, the incidence and character of complications associated with Glidescope use were recorded. Predictors of Glidescope intubation failure were determined using a logistic regression analysis. Overall success for Glidescope intubation was 97% (1,944 of 2,004). As a primary technique, success was 98% (1,712 of 1,755), whereas success in patients with predictors of difficult direct laryngoscopy was 96% (1,377 of 1,428). Success for Glidescope intubation after failed direct laryngoscopy was 94% (224 of 239). Complications were noticed in 1% (21 of 2,004) of patients and mostly involved minor soft tissue injuries, but major complications, such as dental, pharyngeal, tracheal, or laryngeal injury, occurred in 0.3% (6 of 2,004) of patients. The strongest predictor of Glidescope failure was altered neck anatomy with presence of a surgical scar, radiation changes, or mass. These data demonstrate a high success rate of Glidescope intubation in both primary airway management and rescue-failed direct laryngoscopy. However, Glidescope intubation is not always successful and certain predictors of failure can be identified. Providers should maintain their competency with alternate methods of intubation, especially for patients with neck pathology.
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We compared the intubating characteristics of the Pentax Airway Scope, the C-MAC and the Glidescope with those of the Macintosh laryngoscope in 400 patients without predictors of difficult intubation. We found shorter intubation times with the Airway Scope (mean (SD) 20.6 (11.5) s) compared with the C-MAC (31.9 (17.6) s) and Glidescope (31.2 (15.0) s), p < 0.001. The median (IQR [range]) score for ease of intubation was significantly lower (better) with the Airway Scope (0 (0-8.75 [0-60])) than with the C-MAC (10 (0-20 [0-90])) or Glidescope (0 (0-20 [0-80])), p < 0.001. Ease of blade insertion in the C-MAC (0 (0-0 [0-30])) was superior to that of the Airway Scope (0 (0-0 [0-70])), Macintosh (0 (0-0 [0-80])) or Glidescope (0 (0-10 [0-60])), p = 0.006. More patients had a grade 1 laryngeal view with the Airway Scope (97%) compared with the C-MAC (87%), Glidescope (78%), or Macintosh (58%), p < 0.001. There were no grade 3 laryngeal views with the Airway Scope. The three videolaryngoscopes had comparable first attempt successful intubation rates: 95% for the Airway Scope, 93% for the C-MAC and 91% for the Glidescope.
Article
Although most tracheal intubations with direct laryngoscopy are not performed with a styletted endotracheal tube, it is recommended that a stylet can be used with indirect videolaryngoscopy. Recently, there were several reports of complications associated with styletted endotracheal tubes and videolaryngoscopy. In this study, we compared three videolaryngoscopes (VLSs) in patients undergoing tracheal intubation for elective surgery: the GlideScope Ranger (GlideScope, Bothell, WA), the V-MAC Storz Berci DCI (Karl Storz, Tuttlingen, Germany), and the McGrath (McGrath series 5, Aircraft medical, Edinburgh, UK) and tested whether it is feasible to intubate the trachea of patients with indirect videolaryngoscopy without using a stylet. Four hundred fifty consecutive adults (ASA PS I-II) undergoing tracheal intubation for elective surgery were randomly allocated for airway management with one of the three devices. Anesthesia induction for tracheal intubation consisted of fentanyl-propofol-rocuronium. An independent anesthesiologist used the Cormack-Lehane grading system to score an initial direct laryngoscopic view using a classic metal Macintosh blade. After subsequent positive-pressure ventilation using a face mask and an oxygen-sevoflurane mixture for 1 min, the trachea was intubated using one of the three VLSs. During intubation, the following data were collected: intubation time, number of intubation attempts, use of extra tools to facilitate intubation, and overall satisfaction score of the intubation conditions. The trachea of every patient was intubated using the VLSs, and none of the patients required conversion to the classic Macintosh laryngoscope. All three VLSs offered equal or better view of the glottis as assessed by the mean Cormack-Lehane grade, compared with the traditional Macintosh laryngoscopy, including a larger viewing angle of the glottic entrance. The average intubation time was 34 +/- 20 s for the GlideScope, 18 +/- 12 s for the V-MAC Storz, and 38 +/- 23 s for the McGrath VLS. Intubation with the Storz was faster (P < 0.05) than the other two VLS tested and necessitated fewer additional tools (P < 0.01), resulting in a higher first-pass successful intubation rate. A stylet had to be used in 7% of the patients in the Storz group versus about 50% of the patients when the other two VLS were used. The trachea of a large proportion of patients with normal airways can be intubated successfully with certain VLS blades without using a stylet, although the three studied VLSs clearly differ in outcome. The Storz VLS displaces soft tissues in the fashion of a classic Macintosh scope, affording room for tracheal tube insertion and limiting the need for stylet use compared with the other two scopes. Although VLSs offer several advantages, including better visualization of the glottic entrance and intubation conditions, a good laryngeal view does not guarantee easy or successful tracheal tube insertion. We recommend that the geometry of VLSs, including blade design, should be studied in more detail.