BOUGIE: Bougie vs. Stylet for Emergency Intubation (2021)

“Among critically ill adults undergoing tracheal intubation, the use of a bougie did not significantly increase the incidence of successful intubation on the first attempt as compared with the use of an endotracheal tube with a stylet.”

  • The BOUGIE Trial Investigators

1. Publication Details

  • Trial Title: Effect of Use of a Bougie vs Endotracheal Tube and Stylet on First-Attempt Intubation Success Among Patients With Difficult Airways Undergoing Tracheal Intubation: A Randomized Clinical Trial
  • Citation: 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 Tracheal Intubation: A Randomized Clinical Trial. JAMA. 2018;319(21):2179–2189. DOI: 10.1001/jama.2018.6496. Note: The main BOUGIE trial was published in 2021. The 2018 publication is a related but different trial (the BEAM trial) by some of the same authors.
  • Published: June 24, 2021, in The Journal of the American Medical Association (JAMA)
  • Author: Brian E. Driver, M.D.
  • Funding: United States National Heart, Lung, and Blood Institute (NHLBI).

2. Keywords

  • Tracheal Intubation, Airway Management, Bougie, Stylet, Critical Care, Emergency Medicine, Randomized Controlled Trial

3. The Clinical Question

  • In critically ill adults undergoing tracheal intubation (Population), does the routine use of a bougie (Intervention) compared to an endotracheal tube with a stylet (Comparison) increase the rate of successful intubation on the first attempt (Outcome)?

4. Background and Rationale

  • Existing Knowledge: Successful tracheal intubation on the first attempt is critical to prevent complications like hypoxemia and cardiac arrest. A tracheal tube introducer, commonly known as a bougie, is often used as a rescue device after a failed intubation attempt, particularly when the view of the larynx is poor.
  • Knowledge Gap: While effective as a rescue tool, it was unknown if using a bougie as the primary device for all intubations in critically ill patients would improve first-pass success rates compared to the standard technique of using an endotracheal tube with a malleable stylet.
  • Proposed Hypothesis: The authors hypothesized that the routine use of a bougie would be superior to the use of an endotracheal tube with a stylet in achieving successful intubation on the first attempt.

5. Study Design and Methods

  • Design: A multicenter, pragmatic, randomized, controlled trial (used to test the effectiveness of interventions).
  • Setting: 15 emergency departments and intensive care units (ICUs) in the United States.
  • Trial Period: Enrollment ran from April 2019 to February 2021.
  • Population:
    • Inclusion Criteria: Critically ill adult patients (≥18 years) undergoing tracheal intubation.
    • Exclusion Criteria: Included prisoners, pregnant patients, and patients with an immediate need for a surgical airway.
  • Intervention: Patients were intubated using a bougie as the primary device.
  • Control: Patients were intubated using a standard endotracheal tube with a malleable stylet.
  • Management Common to Both Groups: The choice of laryngoscope (direct or video), sedative and paralytic agents, and all other aspects of care were at the discretion of the treating clinicians.
  • Power and Sample Size: The authors calculated that a sample size of 1100 patients would provide 90% power to detect a 7% absolute difference in first-attempt intubation success. (Power is a study’s ability to find a real difference between treatments if one truly exists; 90% power means the study had a 90% chance of detecting the specified effect, which is considered very high).
  • Outcomes:
    • Primary Outcome: Successful intubation on the first attempt.
    • Secondary Outcomes: Included the incidence of severe hypoxemia (SpO2 < 80%) and esophageal intubation.

6. Key Results

  • Enrollment and Baseline: 1106 patients were randomized (556 to the bougie group and 550 to the stylet group). The groups were well-matched at baseline. A majority of intubations were performed with a video laryngoscope.
  • Trial Status: The trial was completed as planned.
  • Primary Outcome: There was no significant difference in the primary outcome. Successful intubation on the first attempt occurred in 447 of 556 patients (80.4%) in the bougie group and in 453 of 550 patients (82.4%) in the stylet group (p=0.27).
  • Secondary Outcomes: There were no significant differences between the groups in the incidence of severe hypoxemia or esophageal intubation.
  • Adverse Events: The incidence of airway management-related adverse events was similar in both groups.

7. Medical Statistics

  • Analysis Principle: The trial was analyzed using an intention-to-treat principle.
  • Statistical Tests Used: The primary outcome was analyzed using a chi-square test.
  • Primary Outcome Analysis: The primary outcome was a comparison of the proportions of successful first-attempt intubations between the two groups.
  • Key Statistic(s) Reported: The key statistics were the absolute success rates and the associated P-value.
  • Interpretation of Key Statistic(s):
    • P-value: The p-value of 0.27 is much higher than the 0.05 threshold, indicating that the small difference in first-pass success between the groups was not statistically significant and was very likely due to chance (a result is conventionally considered statistically significant if the p-value is less than 0.05).
  • Clinical Impact Measures:
    • Absolute Risk Difference:
      • Formula: ARD = (Risk in Intervention Group) – (Risk in Control Group)
      • Calculation: ARD = 80.4% – 82.4% = -2.0%.
      • Clinical Meaning: The bougie group had a 2% lower first-pass success rate, a difference that was not statistically significant.
  • Subgroup Analyses: No significant differences were found in any of the pre-specified subgroups, including when a video laryngoscope was used or when the operator was less experienced.

8. Strengths of the Study

  • Study Design and Conduct: The large, multicenter, pragmatic, randomized design provides a high level of evidence.
  • Generalizability: The inclusion of both emergency department and ICU patients from 15 diverse sites increases the external validity of the findings.
  • Statistical Power: The study was large and adequately powered to detect a clinically meaningful difference if one existed.
  • Patient-Centered Outcomes: The primary outcome of first-attempt success is a critical, patient-centered procedural outcome.

9. Limitations and Weaknesses

  • Internal Validity (Bias):: The study was unblinded, which is a potential source of performance bias. Operators could not be blinded to the device they were using.
  • External Validity (Generalizability): The majority of operators in the trial were resident physicians, and the majority of intubations were performed with video laryngoscopy. The results may not be fully generalizable to more experienced operators or to settings where direct laryngoscopy is more common.
  • Other: The first-pass success rate in the stylet group (82.4%) was very high, which may have made it difficult for the bougie to show a superior benefit (a ceiling effect).

10. Conclusion of the Authors

  • Among critically ill adults undergoing tracheal intubation, the use of a bougie did not significantly increase the incidence of successful intubation on the first attempt as compared with the use of an endotracheal tube with a stylet.

11. To Summarize

  • Impact on Current Practice: This large, high-quality trial provides strong evidence that the routine, “bougie-first” strategy is not superior to a standard “stylet-first” approach for all critically ill patients.
  • Specific Recommendations:
    • Patient Selection: For the general population of critically ill adults undergoing emergency intubation.
    • Actionable Intervention: The results suggest that either a bougie or a stylet are acceptable as the primary device for intubation, with no evidence of superiority for the bougie.
  • What This Trial Does NOT Mean: This trial does NOT mean that the bougie is not a useful tool. It remains an essential rescue device for difficult airways, and its benefit in that specific context was not tested here.
  • Implementation Caveats: The choice of primary intubating device (bougie vs. stylet) should be based on operator experience and preference, as this trial shows no clear benefit of a “bougie-for-all” policy.

12. Context and Related Studies

  • Building on Previous Evidence: The BOUGIE trial (2021) was designed to test if the benefit of a bougie seen in a previous single-center trial (the BEAM trial, 2018) would hold true in a larger, multicenter setting.
  • Influence on Subsequent Research: The definitive neutral finding of this large trial will likely be practice-affirming for most clinicians and will be highly influential in airway management guidelines, discouraging a mandatory “bougie-first” policy.

13. Unresolved Questions & Future Directions

  • Unresolved Questions: The key unresolved question is whether there is a specific subgroup of patients with very difficult airways (e.g., a poor laryngeal view) where a primary bougie-first approach might still be beneficial.
  • Future Directions: Future research may focus on identifying which specific patient or operator characteristics might predict success with one device over the other, allowing for a more personalized approach to airway management.

14. External Links

15. Framework for Critical Appraisal

  • Clinical Question: The research question was highly relevant, addressing a common and critical procedural question in emergency and critical care medicine.
  • Methods: The large, multicenter, pragmatic RCT design was appropriate and robust. The main methodological weakness is the lack of blinding, which is unavoidable in a procedural trial.
  • Results: The study reported a clear neutral finding for its primary outcome, with a narrow confidence interval that included the null value. This provides strong evidence against a meaningful clinical benefit of a routine bougie-first strategy in this population.
  • Conclusions and Applicability: The authors’ conclusion is a direct and fair reflection of the data. The high external validity of this pragmatic trial means its findings are broadly applicable to most modern emergency departments and ICUs, particularly where video laryngoscopy is common.

16. Disclaimer and Contact

  • This summary is provided by the Academic Committee of ESBICM (ACE) to facilitate the understanding of this study; readers are advised to refer to the original trial document for a deeper understanding. If you find any information incorrect, or missing, or it needs an update or have a request for a specific critical care trial summary, kindly write to us at academics[at]esbicm.org.
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