Washington University Emergency Medicine Journal Club– March 17th, 2022
You are the teaching resident TCC once weekend when you get a page that EMS is bringing in a 58-year-old gentleman in respiratory distress. Per the page, he is currently on CPAP, tripodding, with an O2 saturation of 86%, a heart rate of 140, and a BP of 180/80. With a 5-minute ETA, you quickly grab your junior resident and being prepping the room. You pull the CMAC and ultrasound machines into the room, set up suction, and make sure your respiratory therapist has BiPAP and a bag-valve mask ready.
The patient arrives and appears much as he was described in the page. He is quickly placed on BiPAP while EMS gives you additional information. The patient has a history of COPD with prior intubations, no history of heart disease, and called this morning for worsening shortness of breath. He received dexamethasone IV and two duonebs prior to being placed on CPAP. The patient is unable to answer questions due to respiratory distress and somnolence. His O2 saturation is only 89% once placed on BiPAP.
You quickly make the decision to intubate given the patient’s appearance, with the full support of your attending. As the nurse draws up RSI meds, you perform a bedside ultrasound that reveals grossly normal cardiac function with no pericardial effusion. You see normal lung slide and no B-lines on lung ultrasound. You have your junior resident prep the CMAC with a number 4 MAC blade. The respiratory therapist has an ET tube ready, but you inform the junior that she will be using a bougie with the tube rather than a stylet, due to an increase in first-pass success rates with this approach. Your attending watches as the intubation goes smoothly, but later informs you that there is still controversy as to whether the bougie-first approach is truly beneficial. As your junior begins to work on her note, you do a quick search of the medical literature to see what the evidence shows…
Population: Adults patients undergoing non-elective endotracheal intubation
Intervention: Use of a bougie on the first intubation attempt
Comparison: Traditional use of an endotracheal tube and stylet for the first
Outcome: First-pass intubation success, number of intubation attempts, overall
duration of intubation, hypoxemia
PubMed was searched using the terms “bougie first AND intubation” resulting in 132
citations (https://tinyurl.com/mr3twm4c). Of these, three hospital-based and one
EMS study were identified for inclusion in this review.
Article 1: Driver B, Dodd K, Klein LR, Buckley R, Robinson A, McGill JW, Reardon RF, Prekker ME. The Bougie and First-Pass Success in the Emergency Department. Ann Emerg Med. 2017 Oct;70(4):473-478.e1. doi: 10.1016/j.annemergmed.2017.04.033. PMID: 28601269. Answer Key
Article 2: 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. Answer Key.
Article 3: Driver BE, Semler MW, Self WH, et al. Effect of Use of a Bougie vs Endotracheal Tube With Stylet on Successful Intubation on the First Attempt Among Critically Ill Patients Undergoing Tracheal Intubation: A Randomized Clinical Trial. JAMA. 2021;326(24):2488–2497. doi:10.1001/jama.2021.22002. Answer Key.
Article 4: 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. Answer Key.
The bougie, first described as an adjunct for difficult oral intubations in 1949 (Macintosh 1949), has since become a relatively ubiquitous device whose use in difficult orotracheal intubations has been well-described. Several studies published over the last 5 years have evaluated the use of the bougie on the initial attempt at intubation, rather than as a rescue device alone. These studies originated out of Hennepin County Medical Center (HPMC) in Minneapolis, Minnesota, where the bougie is routinely used as a first-line intubation device.
The first of these was a single-center, retrospective, observational study conducted at HCMC itself. The first-pass intubation success rate for all adult intubations in the ED in which a bougie was used as the first-line device were compared with rates in cases where an endotracheal (ET) tube and stylet were used. First-pass success rates were higher when a bougie was used compared to an ET tube and stylet (95% vs. 86%, difference 9%; 95% CI 2-16%). This difference remained after multivariate analysis to control for certain confounders (adjusted OR 2.83; 95% CI 1.35-5.92). No difference in rates of hypoxemia was observed.
These results were later confirmed in a randomized controlled study at the same institution in which 757 patients were randomized in a 1:1 fashion to intubation with a bougie or an ET tube and stylet. Among patients with at least one difficult airway characteristic, first-pass success rates were higher in the bougie group compared to the ET tube and stylet group (96% vs. 82%, difference 14%; 95% CI 8-20%). A similarly higher rate of first-pass success was seen with bougie use when evaluating all randomized patients (difference 8%; 95% CI 4-12%). Again, no difference in rates of hypoxemia was observed.
While the results of these two studies are interesting, there are a few confounders that could explain the improved success rates observed with bougie use and may limit the external validity of these findings. First, fist-line bougie use is considered standard-of-care at HCMC, and all residents are trained primarily in this methodology. Better familiarity with the bougie versus an ET tube and stylet may explain the apparent superiority observed. In addition, intubations at HCMC are performed almost exclusively by senior emergency medicine residents (96% and 86%, respectively), which may not be true at many academic centers. Finally, while video-assisted intubation was performed in most cases in both studies, the screen was not viewed in the majority of cases; in the initial study, the screen was viewed in 46% and 19% of bougie and ET tube intubations, respectively, with only somewhat higher numbers in the subsequent study (42% and 51%).
To evaluate the potential influence of these factors on success rates, these investigators conducted a multi center, randomized controlled trial at 7 EDs and 8 ICUs in 11 US hospitals. Of note, the HCMC ED was not a study site in this trial. Out of 1102 patients randomized to either bougie-first intubation or ET tube and stylet, successful first-pass intubation occurred with similar frequency among the two groups (80.4% vs. 83.0%, difference -2.6%; 95% CI -7.3 to 2.2%). Rates of hypoxemia and airway complications were no different in the two groups.
Bougie-first intubation has also been studied outside of the hospital. A recent prehospital, before-and-after, observational study conducted in Seattle, Washington compared first-pass success rates over an 18-month period prior to a process change and the subsequent 18-month period following this change. This process change included a 3-month training period during which paramedics were instructed and trained to use a bougie for all first attempts at intubation. The first-attempt success rate was higher in the post-intervention group compared to the control group (77% vs. 70%, difference 7.0%; 95% CI 3% to 11%). Unfortunately the authors were not able to compare rates of hypoxemia or intubation duration between the groups. While this improved first-pass intubation rate is interesting, the observed treatment effect is quite possibly due to heightened awareness and intubation expertise in the immediate post-training period rather than an actual benefit of bougie use itself. Repeat measurements of the outcome several months after the training period to ensure retention would have been helpful to verify the benefits seen.
While there is some evidence supporting first-attempt bougie intubation, these trials were performed at a single-center in which this is already standard procedure and these results were not confirmed in a large, multi-center study. These findings, however, do not definitively refute the potential benefits of bougie-first intubation, as no training was provided on bougie use, and nearly all participants performed only one intubation in the study. It possible that even a minimal degree of training with the bougie would lead to similar improvements in first-pass success seen in the studies performed at HCMC. On the other hand, the single prehospital study demonstrated improved first-pass success with bougie use, but this occurred after a 3-month training period whose occurrence may have improved intubation skills in general. Overall, this evidence suggests that first-attempt intubation with a bougie is at least no worse than use of an ET tube and stylet, and with training may improve first-pass success.