SGEM#271: Bougie Wonderland for First Pass Success

Date: October 17th, 2019 Reference: Driver 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 May 2018 Guest Skeptic: Missy Carter, former City of Bremerton Firefighter/Paramedic, currently a physician assistant practicing in emergency medicine in the Seattle area and an adjunct faculty member with the Tacoma Community College paramedic program. Case: You are preparing for a rapid sequence intubation in a patient suffering from respiratory distress. While doing your airway assessment you notice some difficult airway characteristics (obese patient with a small mouth opening). In the past you’ve had failed first pasts attempts on a similar patient and used a bougie as your back up device. You wonder if this time you would be more successful using the bougie for your first attempt. Background: We have covered airway a number of times on the SGEM. This has included supraglottic airways for OHCA (SGEM#247), POCUS for confirming endotracheal tube placement (SGEM#249) and non-invasive positive pressure ventilation for OCHA (SGEM#96) just to name a few. However, we have never covered the issue of using a bougie for intubation.  For many years the bougie has been considered a back up or “rescue” airway tool and only pulled out after one or even several failed intubation attempts. Many studies have shown that multiple intubation attempts can increase mortality and morbidity, so we are always striving to increase our first pass intubation success rates to improve patient care. Clinical Question: Does using a bougie increase first pass intubation success? Reference: Driver et al. The Bougie and First-Pass Success in the Emergency Department. Annals of Emergency Medicine 2017 Population: Adult patients (age > 17 years) who underwent intubation in the emergency department Excluded: Patients with missing videos that recorded the intubation, cases in which a bougie was used with a hyper angulated video laryngoscope blade (GlideScope) or were intubated before arrival to the emergency department Intervention: Bougie with Macintosh or CMAC laryngoscope Comparison: Intubation with endotracheal tube and stylet Outcome: Primary Outcome: First-pass success rates Secondary: Duration of attempts, hypoxia and esophageal intubations Authors’ Conclusions: “Bougie was associated with increased first-pass intubation success. Bougie use may be helpful in ED intubation.” Quality Checklist for Observational Study: Did the study address a clearly focused issue? Yes Did the authors use an appropriate method to answer their question? Yes Was the cohort recruited in an acceptable way? Yes Was the exposure accurately measured to minimize bias? Yes Was the outcome accurately measured to minimize bias? Yes Have the authors identified all-important confounding factors? Yes Was the follow up of subjects complete enough? Yes How precise are the results? Fairly precise given the small sample size Do you believe the results? Yes Can the results be applied to the local population? Unsure Do the results of this study fit with other available evidence? Yes Key Results: There were 543 patients included in this cohort. The median age was in the late 40’s and more than two-thirds were male. The vast majority (~95%) of the intubations were performed by a senior resident. First-pass success was greater with than without bougie Primary Outcome: First-pass success 95% with bougie vs. 86% without bougie Absolute difference 9% (95% CI; 2% to 16%) Secondary Outcomes:  Median first-attempt duration was higher with than without bougie (40 seconds vs. 27 seconds) with a difference of 13 seconds (95% CI; 11 to 16). Hypoxia 17% with and 13% without bougie Esophageal intubation 1 with and 1 without bougie 1. External Validity: This is clearly a bougie center of excellence. Of the 543 intubations included in this study, 435 used the bougie as the first-time airway tool. This raises the question of generalizability. If providers in this center are more proficient with the use of a bougie than the average emergency medicine clinician, would we see different results if we put the bougie in the hands of someone who does not use it regularly? In addition, 95% of the intubations were done by residents. Does this have external validity to non-teaching sites where the attending physician is performing the intubations? 2. Missing Data: Although these cases were consecutive; 83 cases had to be excluded due to missing video. The videos in addition to chart review were the primary data collection tools. The authors addressed this limitation with a sensitivity analysis that showed the bougie would still be superior. 3. Associations: The retrospective nature of this study makes it difficult to eliminate bias. The reviewers did their best to mitigate this by using multiple reviewers for the videos looking from multiple angles. Three separate investigators watched all cases from three cameras. They were blinded to the study goals and simply reported information on a standardized form. However, it was not a randomized trial and so we cannot claim causation only association between bougie and first pass success rates. 4. Why Use the Bougie: It is unknown why the bougie was used in each case. The authors’ attempted to identify difficult airway characteristics (obesity, cervical spine immobilization, presence of abnormal anatomy, facial trauma, masses, and body fluids) that could have influenced the operators’ decision. They also screened for hypoxia and esophageal intubations. These characteristics were about the same between groups which suggests the providers used bougie as first line device regardless of difficult airway characteristics. 5. Patient-Oriented Outcomes: They used first pass success rates, duration and hypoxia as surrogate markers. Important patient-oriented outcomes would have been survival and survival with good neurological function. While there was a longer time for ETT insertion with a bougie than without (13 seconds) it is unlikely this was a clinically important difference. Rates of hypoxia among the two groups were similar (13% with bougie and 17% without). Unfortunately, there is missing data on hypoxia in a total of 181 cases (114 missed on video feed and 67 were missed due to poor wave forms). It’s possible that this missing information may have shown a significant increase in hypoxia for our bougie patients. Comment on Authors’ Conclusion Compared to SGEM Conclusion: We agree with the authors’ conclusions. SGEM Bottom Line: The use of a bougie is associated with increased first pass success rates for intubations in the emergency department but an RCT is needed to further explore this topic. Clinical Application: But wait there is more. We are going to do two papers today on the SGEM. The second paper is a randomized control trial looking at this issue by the same lead author. Reference: Driver 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 May 2018 Population: Adult patients (>17 years of age) who underwent intubation in the emergency department and the attending emergency physician planned to use a Macintosh laryngoscope blade on the first attempt Exclusions:Prisoners, suspected or known pregnant patients and patients with known distortion of the upper airway or glottic structures Intervention: Bougie with Macintosh or CMAC laryngoscope Comparison: Intubation with endotracheal tube and stylet Outcome: Primary Outcome: First-attempt intubation success Secondary Outcomes: Duration of attempts, hypoxemia (SpO2 <90% or a 10% decrease) and esophageal intubation Authors’ Conclusions: “In this emergency department, use of a bougie compared with an endotracheal tube + stylet resulted in significantly higher first-attempt intubation success among patients undergoing emergency endotracheal intubation. However, these findings should be considered provisional until the generalizability is assessed in other institutions and settings.” Quality Checklist for Randomized Clinical Trials: The study population included or focused on those in the emergency department. Yes The patients were adequately randomized. Yes The randomization process was concealed. Yes The patients were analyzed in the groups to which they were randomized. Yes The study patients were recruited consecutively (i.e. no selection bias). Yes The patients in both groups were similar with respect to prognostic factors. Yes All participants (patients, clinicians, outcome assessors) were unaware of group allocation. No All groups were treated equally except for the intervention. Yes Follow-up was complete (i.e. at least 80% for both groups). Yes All patient-important outcomes were considered. No The treatment effect was large enough and precise enough to be clinically significant. Yes Key Results: They enrolled 757 patients that included 380 with a difficult airway characteristic. The mean age was in the mid-40’s with more than two-thirds being male. The vast majority (85%) were intubated by a senior resident or fellow. Only 1% were intubated by emergency medicine faculty. The rest were intubated by junior residents. First-pass success was greater with than without bougie Primary Outcome: First-attempt intubation success 96% with bougie group and 82% without bougie Absolute difference of 14% (95% CI; 8-20) Secondary Outcomes: Median first-attempt duration was similar (38 seconds vs 36 seconds)