Critical Care Medicine Section: Bougie Conundrum: Airway Adjunct or Secret to 1st Pass Success? Should We Incorporate into Routine Practice and How?

CRITICAL CARE MEDICINE SECTION

Bougie Conundrum: Airway Adjunct or Secret to 1st Pass Success? Should We Incorporate into Routine Practice and How?

Frederick Gmora, DO, Skyler Lentz, MD FAAEM, Elias Wan, MD FAAEM

Emergency medicine at its purest form is controlled chaos. Apart from the occasional warning of a potential impending disaster, one can never predict who will present next during a hectic clinical shift. The ability to anticipate, strategize, and react rapidly to disasters are essential qualities of the emergency physician or intensivist. Considering emergency airway management, whether it be within the walls of the emergency department or the intensive care unit, there is no exception. The timing of a patient’s last meal, pre-oxygenation status, or mouth full of emesis matters little when they arrive in extremis. Thus, a well-prepared physician will control the chaos by optimizing the conditions to maximize their first pass success rate.

Fortunately, for the majority, the number of exceptionally difficult airways or complex anatomy scenarios only comprise a small percentage of the overall cases of intubations. Overall, emergency physicians successfully intubate >99% of patients in three attempts or less, with an 83% first pass success rate. While few desire more daunting challenges, the smaller integer does pose a unique challenge for trainees to gain experience and be prepared for the worse. How do they build their armory of adjuncts for the difficult airway?

One adjunct often included in emergency airway preparations is the tracheal tube introducer or bougie. It is a commonly described difficult airway adjunct for failed intubation attempts or poor initial laryngoscopic view. The bougie itself is certainly not new, described by Macintosh in 1949, nonetheless, it remains utilized in only a small fraction of intubations.

However, in the last several years there has been a paradigm shift towards utilizing the bougie as the initial attempt device. The shift is in large due to two papers by Driver and colleagues at Hennepin County Medical Center in Minneapolis, Minnesota. The first study, published in 2017, is a retrospective, observational study which showed higher first pass success with the bougie vs. the more conventional stylet and endotracheal tube (ETT) combination when accounting for confounding variables. The Bougie Use in Emergency Airway Management (BEAM) trial was published a year later out of the same emergency department.T his was a randomized control trial comparing first attempt intubation success with the bougie vs. ETT and stylet with those individuals with difficult airway characteristics. Again, there was a significant increase in first pass success in the bougie arm in those with at least one difficult airway predictor (96% vs. 82%) and in the whole study population (98% vs. 87%). Notably, the duration of the first intubation attempt and incidence of hypoxemia was not different between the bougie and stylet groups.

These two studies though are not without their limitations. Most critical for this discussion is related to their generalizability. They were both conducted at a single center which limits their generalizability. Perhaps more notable for the majority of emergency physicians, located outside this center, was their pre-existing comfort with the bougie as a widely used primary method since 1996.

The two above papers, however, do suggest that the bougie can be considered an alternative to a traditional stylet, without increased risk of adverse events, and potentially higher success in the hands of an experienced operator. In fact, some prehospital studies, meta-analysis, and simulation studies suggest that bougie as first pass device can be superior. The challenge remains on the best way to enhance expertise in a controlled fashion during real-world applications.

Proposed is a method that I began employing as a senior resident and have incorporated into my practice for educating trainees during clinical shifts. Begin with a video laryngoscope with a Macintosh blade. The Macintosh blade allows for both direct or video laryngoscopy, if desired, and avoids the challenge of navigating the hyper-angulated blade. The endotracheal tube should be pre-loaded onto the bougie itself before commencing, similar to the ETT and a stylet (Figure 1). The utilization of the video laryngoscope is twofold. First, it allows for direct supervision of the airway operator in real time. Secondly, the trainee can directly visualize the bougie passing through the vocal cords while experiencing the tactile feedback of the tracheal rings.

To build confidence the learner can use the visualization to practice “traditional” blind techniques when intubating with a bougie. One such technique includes rotating the ETT 90° counter clockwise so the tip is vertical when encountering resistance while passing the ETT over the bougie. Another technique is the “hold up sign” to confirm appropriate position in the airway, which is advancing the bougie in a controlled manner till there is gentle resistance due to tip lodging in the small airways, rather than freely advancing in the esophagus, or a maximum of 35 cm. This is likely to be undertaken with a team comprised of a minimum of two clinicians initially (a second clinician to advance the ETT over the bougie once in place), but will eventually allow the person performing the intubation to master various one-handed grips and single person techniques. The desired endpoint is to gain confidence and expertise in an ideal controlled setting, allowing translation to a substantially more chaotic one.

While the level of evidence does not yet support the removal of stylets from standard airway boxes, Driver and colleagues provide insight to the routine use of a bougie as a safe and effective alternative, with potentially increased first pass success in the hands of a skilled operator. The ability to incorporate routine bougie usage into practice in a safe and effective manner is paramount to obtaining the same first pass success rates in the BEAM Trial. Only time will tell if such success can be replicated and generalizable in a prospective multicenter trial by Driver et al.8 Nonetheless, the method described above is one way to safely obtain this expertise and train the next generation of emergency medicine and critical care physicians.

References

* Division of Surgical Critical Care, Traumatology, and Emergency Surgery, Perelman School of Medicine, University of Pennsylvania; Philadelphia, PA Division of Emergency Medicine and Pulmonary Diseases & Critical Care Medicine, University of Vermont Medical Center, Burlington, VT Department of Surgery and Emergency Medicine, Maimonides Medical Center, Brooklyn, NY

1. Brown CA 3rd, Bair AE, Pallin DJ, Walls RM; NEAR III Investigators. Techniques, success, and adverse events of emergency department adult intubations [published correction appears in Ann Emerg Med. 2017 May;69(5):540]. Ann Emerg Med. 2015;65(4):363-370.e1. doi:10.1016/j. annemergmed.2014.10.036

2. Macintosh RR. An Aid to Oral Intubation. Br Med J. 1949;1:28

3. Driver B, Dodd K, Klein LR, et al. The Bougie and First-Pass Success in the Emergency Department. Ann Emerg Med. 2017;70(4):473-478.e1. doi:10.1016/j.annemergmed.2017.04.033

4. 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. doi:10.1001/ jama.2018.6496

5. Latimer AJ, Harrington B, Counts CR, Ruark K, Maynard C, Watase T, Sayre MR. Routine Use of a Bougie Improves First-Attempt Intubation Success in the Out-of-Hospital Setting. Ann Emerg Med. 2021 Mar;77(3):296-304. doi: 10.1016/j.annemergmed.2020.10.016. Epub 2020 Dec 17. PMID: 33342596.

6. Shah KH, Melville LD. Does the Use of a Bougie Improve First-Attempt Intubation Success Compared With a Stylet? Ann Emerg Med. 2020 May;75(5):640-641. doi: 10.1016/j.annemergmed.2019.09.003. Epub 2019 Nov 20. PMID: 31759751.

7. Baker JB, Maskell KF, Matlock AG, Walsh RM, Skinner CG. Comparison of Preloaded Bougie versus Standard Bougie Technique for Endotracheal Intubation in a Cadaveric Model. West J Emerg Med. 2015 Jul;16(4):58893. doi: 10.5811/westjem.2015.4.22857. Epub 2015 Jun 23. PMID: 26265978; PMCID: PMC4530924.

8. Driver B, Semler MW, Self WH, Ginde AA, Gandotra S, Trent SA, Smith LM, Gaillard JP, Page DB, Whitson MR, Vonderhaar DJ, Joffe AM, West JR, Hughes C, Landsperger JS, Howell MP, Russell DW, Gulati S, Bentov I, Mitchell S, Latimer A, Doerschug K, Koppurapu V, Gibbs KW, Wang L, Lindsell CJ, Janz D, Rice TW, Prekker ME, Casey JD; BOUGIE Investigators# and the Pragmatic Critical Care Research Group. BOugie or stylet in patients UnderGoing Intubation Emergently (BOUGIE): protocol and statistical analysis plan for a randomised clinical trial. BMJ Open. 2021 May 25;11(5):e047790. doi: 10.1136/bmjopen-2020-047790. PMID: 34035106; PMCID: PMC8154972.