Effect of Dynamic Versus Stylet-Guided Intubation on First-Attempt Success in Difficult Airways Undergoing Glidescope Laryngoscopy: A Randomized Controlled Trial

Abstract

BACKGROUND: Tracheal intubation failure in patients with difficult airway is still not uncommon. While videolaryngoscopes such as the Glidescope offer better glottic vision due to an acute-angled blade, this advantage does not always lead to an increased success rate because successful insertion of the tube through the vocal cords may be the limiting factor. We hypothesize that combined use of Glidescope and fiberscope used only as a dynamic guide facilitates tracheal intubation compared to a conventional Glidescope technique with a preshaped nondynamic stylet. METHODS: One hundred sixty adult patients with predicted difficult airway were randomly assigned to a conventional Glidescope (standard Glidescope group) or a combined Glidescope + fiberscope group intubation. In the Glidescope + fiberscope group under direct vision from the Glidescope, tracheal intubation was performed using the fiberscope as a guide without using fiberoptic vision, while in the standard Glidescope group, a conventional stylet-guided intubation technique was performed. We evaluated the rate of tracheal intubation success at first attempt as the primary end point (Fisher exact test). The difference between groups in airway injury, time to successful intubation, and the need for an alternative technique was also evaluated. RESULTS: First-attempt intubation success was higher in the Glidescope + fiberscope group than in the standard Glidescope group (91% vs 67%; P = .0012; fragility index, 8; absolute risk reduction, 24% [95% CI, 12%–36%]). Median time to successful tracheal intubation was shorter in the Glidescope + fiberscope group (50 vs 64 seconds; P = .035). Airway injury rate was lower in the Glidescope + fiberscope group than in the standard Glidescope group (1% vs 11%; P = .035; fragility index, 1; absolute risk reduction, 10% [95% CI, 3%–18%]). Alternative rescue technique requirements to achieve tracheal intubation were higher in the standard Glidescope group (24% vs 4%; P < .001; fragility index, 7). CONCLUSIONS: The use of a dynamic, flexible guide during a Glidescope laryngoscopy in patients with a predicted difficult airway compared to a standard intubation technique improves first-attempt intubation success, decreases the incidence of airway injury and time to successful intubation, as well as the need of an alternative technique to succeed.

A randomised crossover comparison of two endotracheal tube introducers: the FROVA and the Flexible Tip Bougie for GlideScope intubation of a difficult airway manikin by infrequent intubators

“…The GlideScope's decreased working space and acute laryngeal entry angle compared with the MacIntosh laryngoscope has led to investigation of the "can see but can't intubate" situation. Case reports have suggested that the flexible tip of a videobronchoscope (fiberscope) can prevent ETT impingement on the trachea [14,15], and a prospective clinical trial showed that a flexible tip ETI (fiberscope) was superior to a preshaped stylet [6]. A comparison of the FROVA and the FTB with experienced intubators using the GlideScope showed faster and easier intubation with the FTB [7], and another manikin study using a MacIntosh laryngoscope showed superiority of the FTB during simulated cardiac arrest [16].…”

“…Alternatively, some ETIs have a flexible tip replicating the action of a flexible bronchoscope (fiberscope) tip. When a fiberscope is used by experienced intubators as a "dynamic introducer", it is superior to a stylet in difficult GlideScope intubation [6].…”

Emerging trends, techniques, and equipment for airway management in pediatric patients

“…A randomized controlled trial of 160 adult patients with anticipated difficult airways demonstrated the use of this combined technique of VL with a flexible scope as stylet resulted in higher first‐pass success rates, shorter time to successful intubation, and lower rates of airway injury when compared with hyperangulated VL alone . This technique has also been used successfully in children who are difficult to intubate .…”

Two Endotracheal Tubes in One Trachea with a Traumatic Injury

“…With difficult airways, the FOB is often used as a "smart stylet" [8] to introduce an ETT directly into the 2 Case Reports in Anesthesiology trachea while the VL is used to visualize the glottic opening. One randomized controlled clinical trial was able to determine the superiority of a combined VL/FOB technique in successful intubation on first attempt, quicker intubation times, and less injury during intubation [9]. e utility of this combined approach in trauma patients with facial fractures has also been described [10].…”