Ever since the BEAM (Bougie Use in Emergency Airway Management) trial was published in JAMA in 2018, the use of the bougie has become increasingly mainstream.1 Some of the advantages of using a bougie are known, but there are also misconceptions about its use, how to maximize success with it, and why we should be using it for most, if not all, airways. We’ll summarize that here. 

Background

The use of the gum elastic bougie was first described in a 1949 letter by Dr. R.R. Macintosh (of whose eponymous laryngoscope blade we are all familiar).² In that letter, Dr. Macintosh wrote about using what was essentially a urinary catheter. The term “gum elastic bougie” is actually somewhat of a misnomer; the most common form of the bougie as we know it was introduced in 1973 as the Eschmann tracheal tube introducer, and it is not made of gum, not elastic, and not a bougie (at least with respect to the original medical definition, that being a cylindrical instrument meant for introduction into the urethra or other tubular structures in order to dilate constrictures).³ Nevertheless, the name has stuck.

Why Use a Bougie?

First and foremost, the bougie leads to increased first-pass success in obtaining a definitive endotracheal airway. In the BEAM trial, the bougie had a 98 percent first-pass success rate versus 87 percent in the stylet group. What’s more, in patients with at least one difficult airway characteristic, the bougie group had a successful first attempt in 96 percent of patients compared to 82 percent in the stylet group.

This increased success rate is likely attributable to two factors. The first is the enhanced ability to obtain visual confirmation of tracheal placement compared to direct endotracheal tube (ETT) placement without the bougie. Given its 15 French (5 mm) diameter, it is much easier to visualize passage of the bougie through the vocal folds compared to an ETT and stylet setup. In fact, Dr. Macintosh himself noted this as its principal advantage in his original correspondence.

The second factor has to do with tactile confirmation. This is confirmed in one of two ways by the operator. One can use the angled coudé tip of the bougie to rock it along the tracheal rings, eliciting a “clicking” sensation. One can also (gently) advance the bougie until resistance is felt either at the carina or in either of the mainstem bronchi; this is known as the “hold-up” sign. In one study, tracheal clicks were felt in 89.7 percent of intubations and had a 100 percent specificity of successful ETT placement.⁴ In the same study, the hold-up sign was 100 percent sensitive and specific for successful placement. What’s more, an observer (such as a supervising physician attending on a resident procedure) can place their hand externally on the trachea and independently confirm placement when tracheal clicks are felt.

Trauma airway management offers another situation in which the bougie can come in handy. Manual in-line stabilization (MILS) is known to decrease the grade of view of the glottis. One study showed a prevalence of 22 percent of grade III views in patients with MILS.⁵ That study showed increased intubation success when the bougie was used, and all patients who were unable to be intubated under direct visualization were rescued with the addition of a bougie. 

However, there is one method that can help maximize success in the most difficult of airway scenarios (ie, Cormack-Lehane [CL] views III and IV). Interestingly, this technique appeared in the original paper describing the CL grading system way back in 1984.⁶ It involves first obtaining an adequate view of the cords, then retracting the laryngoscope slightly to allow the epiglottis to drop down, thereby converting the view from a CL grade I to a grade III. You can then use the coudé tip of the bougie to trace the posterior of the surface of the epiglottis through and past the vocal cords. While probably not the best strategy for emergent airway management, this technique can be practiced in any cadaver or in the simulation lab. Arguably, the biggest advantage of a bougie is the ability to pass it blindly into the trachea when adequate visualization is not possible, so mastering this technique can strengthen your repertoire for salvaging the most challenging of airways. 

Moreover, a bougie can also assist with blind digital intubation when necessary.⁷ Also, in the case of moderate and massive hemoptysis, rotating the coudé tip 90 degrees to the right or left after insertion past the cords facilitates selective lung intubation. One cadaver study showed this technique to be successful 100 percent of the time.⁸

In addition to increased first-pass success, the bougie has other useful applications. The “scalpel-bougie-tube” technique has become the preferred method for many operators during the emergency establishment of a surgical airway, and among other places, it is taught in the United Kingdom’s Difficult Airway Society training.⁹ 

Busting Bougie Myths

One common misconception about bougie use is that it should only be used when the vocal cords are not visualized (ie, Cormack-Lehane views IIB, III, and IV). However, it can be argued that without routine use of a bougie, the likelihood of success (ie, proper placement of bougie, confirmation with tracheal clicks or hold-up sign, railroading of tube over the bougie without dislodgment from the trachea, etc.) with a true grade III or IV view may be much less likely. There is literature that points to this. In a study looking at the National Emergency Airway Registry III (NEAR III), a bougie was used in only 3.5 percent of intubations and had a somewhat dismal success rate of 69 percent.¹⁰ Unfortunately, there are no data on how often tracheal clicks or the hold-up sign were used during these attempts. Some detractors of bougies report having never felt clicks while using the device. Both of these observations (the low success rate found in NEAR III and anecdotal reports of failing to detect tracheal clicks) are likely related to inadequate training and practice with the devices. In other words, using the bougie all of the time will make its benefit more likely to be noticed in the smaller number of cases where it stands to impart its greatest effect. In a sense, the BEAM trial provides some evidence for this. In that study, tracheal clicks were reported in a full 91 percent of the attempts. In fairness, that observation also obliquely highlights one of the main limitations of that trial, which is that was a single-center study conducted in a facility where bougies were already in routine use during first-pass attempts. This likely bolstered its findings but also provides support for the idea that practice with the bougie can lead to such positive outcomes. So one might view this less as a limitation and more as an indication of the utility of teaching and promoting the use of a bougie. 

Another concern some have is that the bougie contributes to an increased risk of airway trauma and pneumothorax. There is no high-quality evidence that supports this claim. In fact, the BEAM trial showed no significant difference in rates of pneumothorax, lip laceration, bleeding from the oropharynx or perilaryngeal structures, dental trauma, or direct airway injury between the bougie and stylet groups. A letter in Anesthesia in 2003 found just a single case report of trauma unambiguously caused by a bougie.¹¹ The case involved a patient who required reintubation due to an expanding hematoma soon after undergoing glossectomy and radical neck dissection, and the patient suffered a pharyngeal wall perforation.¹² Meanwhile, stylet use itself (which many anesthesiologists shun) and multiple attempts to intubate have both been associated with airway trauma.^13,14 If bougies lead to increased first-pass success, it follows that a corresponding fewer number of intubation attempts would lower the risk of airway trauma. 

Bougie Pitfalls

One of the most common mistakes when using a bougie is removing the laryngoscope before railroading the endotracheal tube over the bougie. This will cause the tongue and oropharyngeal structures to collapse posteriorly and potentially inhibit passage of the tube. It is therefore imperative to maintain the laryngoscope in place until the tube has passed through the cords      successfully. If resistance is met with the laryngoscope blade still in place, it is likely that the bevel of the ETT has been lodged against the posterior cartilages, thereby prohibiting its progress. This is easily remedied by retracting the tube 1–2 cm, rotating it 90 degrees counterclockwise, and subsequently advancing the tube again.¹⁵

Conclusion

The best way to master the bougie is practice. While the bougie has been around for almost three quarters of a century, it is still widely seen as a backup “adjunct.” However, recent evidence and forward-thinking emergency physicians are starting to change that paradigm. The widespread use of “bougie first” has the potential to revolutionize emergency airway management, leading to better outcomes for patients.

Dr. Cunningham is a PGY2 emergency medicine resident at Maricopa Medical Center in Phoenix, Arizona, with interests in airway management and critical care. In his free time, he is a mediocre mountain biker and wannabe polyglot.

References

1. Driver BE, Prekker ME, Klein LR, et al. Effect of use of a bougie vs endotracheal tube and stylet on first-attempt intubation success among patients with difficult airways undergoing emergency intubation: a randomized clinical trial. JAMA. 2018;319(21):2179-2189. 
2. Macintosh RR. An aid to oral intubation (letter). BMJ. 1949;1:28.
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5. Nolan JP, Wilson ME. Orotracheal intubation in patients with potential cervical spine injuries. An indication for the gum elastic bougie. Anaesthesia. 1993;48(7):630-633.
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11. Hodzovic I, Latto IP, Henderson JJ. Bougie trauma—what trauma? Anaesthesia. 2003;58(2):192-193. 
12. Kadry M, Popat M. Pharyngeal wall perforation—an unusual complication of blind intubation with a gum elastic bougie. Anaesthesia. 1999;54(4):404-405.
13. Marty-Ané CH, Picard E, Jonquet O, et al. Membranous tracheal rupture after endotracheal intubation. Ann Thorac Surg. 1995;60(5):1367-1371.
14. Miñambres E, Burón J, Ballesteros MA, et al. Tracheal rupture after endotracheal intubation: a literature systematic review. Eur J Cardiothorac Surg. 2009;35(6):1056-1062. 
15. Dogra S, Falconer R, Latto IP. Successful difficult intubation. Tracheal tube placement over a gum-elastic bougie. Anaesthesia. 1990;45(9):774-776.