Publication

• Title: 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
• Acronym: BOUGIE
• Year: 2021
• Journal published in: JAMA
• Citation: 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.

Context & Rationale

• Background

  Emergency tracheal intubation in critically ill adults (ICU/ED) is high risk, with frequent hypoxaemia, hypotension and peri-intubation cardiac arrest.
  “First-pass success” is commonly targeted because repeated attempts are associated with escalating complications.
  Bougie-assisted intubation (tracheal tube introducer first, then railroading the tube) is widely used as a rescue adjunct and was increasingly adopted as a default “first-pass” strategy after a prior single-centre ED trial suggested improved first-pass success compared with a styleted tube.²
• Research Question/Hypothesis

  In a multicentre, pragmatic critical care population (ED and ICU), does initial use of a bougie (vs a styleted endotracheal tube) increase successful tracheal intubation on the first attempt?
• Why This Matters

  If bougie-first meaningfully improves first-pass success, it could be a low-cost, widely scalable intervention with direct implications for airway bundles and training.
  Conversely, if no benefit (or harm via longer apnoea time / hypoxaemia), routine bougie-first may represent “cargo-cult” translation from a narrow context into broad critical care practice.

Design & Methods

• Research Question: Among critically ill adults undergoing emergency tracheal intubation in the ED or ICU, does first-attempt use of a bougie (vs a styleted endotracheal tube) increase the proportion successfully intubated on the first attempt?
• Study Type: Multicentre, pragmatic, parallel-group, unblinded randomised clinical trial; 7 EDs and 8 ICUs in the US; 1:1 allocation; stratified by site and location (ED vs ICU).
• Population:
  • Adults (≥18 years) undergoing tracheal intubation in participating EDs/ICUs.
  • Operator planned to use direct laryngoscopy or a non-hyperangulated video laryngoscope blade.
  • Operator clinically willing to use either strategy for the first attempt (i.e., no strong preference/contraindication).
  • Key exclusions: prisoner status; known pregnancy; prior enrolment; intubation already attempted; planned hyperangulated blade; clinician judged that trial procedures would cause unacceptable delay (e.g., immediate “crash” intubation); clinician judged that only one device strategy was appropriate.
• Intervention:
  • Bougie-first strategy for the first attempt: bougie inserted under laryngoscopy, then endotracheal tube advanced over bougie into the trachea.
  • After the first attempt, subsequent attempts and rescue devices were at clinician discretion.
• Comparison:
  • Stylet-first strategy for the first attempt: endotracheal tube preloaded with a stylet and advanced directly under laryngoscopy.
  • After the first attempt, subsequent attempts and rescue devices were at clinician discretion (including crossover to bougie if desired).
• Blinding: Unblinded (operators could not be blinded to device strategy); outcomes were defined a priori and assessed by observer report when available and operator report when not available.
• Statistics: Sample size of 1100 planned to detect a 6% absolute increase in first-attempt success (from 82% to 88%) with 90% power at a two-sided 5% alpha, allowing ~3% missing outcome data; primary analysis by intention-to-treat using an unadjusted absolute risk difference with 95% CI and P value; regression-adjusted analyses prespecified as secondary/supportive.¹
• Follow-Up Period: Primary outcome assessed during the intubation procedure; clinical outcomes reported through day 28 (censored at hospital discharge) and to hospital discharge for in-hospital outcomes.

Key Results

This trial was not stopped early. A prespecified interim analysis at ~50% enrolment was planned; the trial completed enrolment (1106 randomised; 1102 analysed after post-randomisation exclusion of 4 prisoners).

• Primary outcome: bougie-first did not increase first-attempt success (80.4% vs 83.0%; risk difference -2.6 percentage points; 95% CI -7.3 to 2.2; P=0.27).
• Process/safety signals: induction-to-intubation time was longer with bougie (median 124 vs 112 seconds; difference 12 seconds; 95% CI 4 to 20), with numerically more severe hypoxaemia (11.0% vs 8.8%).
• Exploratory outcomes showed lower cardiovascular collapse and lower day-28 mortality with bougie, but these were hypothesis-generating (no multiplicity adjustment; not powered for clinical outcomes).

Internal Validity

• Randomisation and allocation: 1:1 allocation by sequential, opaque envelopes; stratified by site and clinical location (ED vs ICU); variable block sizes; randomisation occurred after laryngoscope selection.
• Dropout / exclusions: 1106 randomised; 4 excluded post-randomisation after discovery of prisoner status; 1102 included in the primary analysis; primary outcome available for all analysed participants.
• Performance / detection bias: Unblinded operators; “number of attempts” and procedural complications may be susceptible to reporting bias; outcomes were protocol-defined, and a sensitivity analysis addressed an alternative “attempt” definition.
• Protocol adherence: High separation of assigned strategy:
  Bougie group: bougie used on first attempt in 547/556 (98.4%); stylet used on first attempt in 3/556 (0.5%); neither device passed on first attempt in 6/556 (1.1%).
  Stylet group: stylet used on first attempt in 521/546 (97.7%); bougie used on first attempt in 12/546 (2.3%); neither device passed on first attempt in 0/546 (0.0%).
• Baseline characteristics: Groups were well balanced (median age 58 years in both; women 41.4% vs 41.2%; ED location 62.9% vs 61.4%; medical ICU 30.4% vs 31.3%).
• Heterogeneity: Broad range of operators and settings (ED and ICU); prespecified subgroup analyses did not demonstrate convincing effect modification (interaction P values all >0.39).
• Timing and dose: “Dose” was a single first-attempt device strategy; induction-to-intubation time was modestly longer with bougie (median +12 seconds), providing a plausible pathway for oxygenation differences.
• Separation of the variable of interest: Device use differed substantially between groups (bougie first attempt 98.4% vs 2.3%), supporting internal separation.
• Adjunctive therapies: Major co-interventions were clinician-directed (e.g., preoxygenation, drugs, laryngoscope type), reducing protocolisation-related performance artefacts but allowing practice variability.
• Outcome assessment: Primary outcome (tracheal intubation success on first attempt) is clinically meaningful and relatively objective; classification of “attempt” and reporting of complications could still introduce measurement noise in an unblinded pragmatic trial.
• Statistical rigour: Planned sample size achieved; primary hypothesis tested once at alpha 0.05; secondary/exploratory outcomes reported with 95% CIs without multiplicity adjustment (appropriately interpreted as exploratory).

Conclusion on Internal Validity: Overall, internal validity appears strong to moderate: randomisation and group balance were robust with excellent protocol separation, but pragmatic unblinding and potential variability in attempt/complication ascertainment introduce residual risk of measurement and performance bias.

External Validity

• Population representativeness: Typical adult ED/ICU emergency intubations in a US multicentre network; high proportion of video laryngoscopy use reflects contemporary practice in well-resourced centres.
• Key exclusions affecting generalisability: Planned hyperangulated blades, “crash” intubations where randomisation would delay care, and situations where clinicians believed only one device was appropriate (anticipated very difficult anatomy or strong operator preference).
• Applicability: Findings likely generalise best to ED/ICU services using direct or non-hyperangulated video laryngoscopy where operators have baseline competence with both bougie and stylet strategies.
• Resource-limited settings: External validity may be reduced where staffing, training, and laryngoscopy equipment differ materially; relative device effects may differ when baseline first-pass success is lower.

Conclusion on External Validity: Generalisability is moderate: applicable to many contemporary ED/ICU airway contexts with equipoise and non-hyperangulated laryngoscopy, but less applicable to crash intubations, hyperangulated video laryngoscopy workflows, or settings with markedly different operator experience and baseline success rates.

Strengths & Limitations

• Strengths: Multicentre pragmatic design across ED and ICU; large sample size with high protocol adherence; clinically meaningful primary endpoint; prespecified analysis plan; sensitivity analysis addressing attempt definition.
• Limitations: Unblinded operators and partial reliance on operator-report for procedural outcomes; exclusion of hyperangulated blades and crash intubations limits applicability; not powered for rare harms or for clinical outcomes such as mortality; secondary/exploratory outcomes not adjusted for multiplicity.

Interpretation & Why It Matters

• Routine bougie-first is not a universal “first-pass success” solution

  In a broad ED/ICU population, first-attempt success was high in both groups and not improved by bougie-first (80.4% vs 83.0%).
• Time-to-intubation and oxygenation trade-offs

  Bougie-first was associated with a modestly longer induction-to-intubation time (+12 seconds) and numerically more severe hypoxaemia, supporting caution in severely hypoxaemic physiology.
• Exploratory signals should not drive practice alone

  Lower cardiovascular collapse and lower 28-day mortality with bougie are intriguing but exploratory; they should inform future mechanistic work and trial design rather than immediate standard-of-care shifts.

Controversies & Subsequent Evidence

• Discordance with prior RCT evidence: The earlier single-centre ED RCT in “difficult airway” emergency intubations reported improved first-pass success with bougie vs stylet, whereas BOUGIE did not; plausible drivers include different case mix, baseline success rates, operator workflow, and contextual differences between “difficult airway enrichment” versus broad pragmatic ICU/ED populations.²
• Attempt definition and procedural mechanics: Correspondence highlighted that bougie-assisted intubation is inherently a two-step manoeuvre (introducer placement then tube railroading), raising concern that “first attempt” definitions could differentially penalise bougie workflows; the trial’s sensitivity analysis using “single laryngoscope insertion” showed similarly null results, mitigating (but not eliminating) this critique.³⁴⁵
• Later meta-analytic synthesis: A subsequent systematic review and meta-analysis incorporating RCT and observational data reported higher first-attempt success with bougie use overall (RR 1.11; 95% CI 1.01 to 1.22), but with heterogeneity across settings and study designs; BOUGIE materially influences the pooled estimate and emphasises that benefit is not uniform across critically ill populations.⁶
• Heterogeneity of treatment effect: A post hoc machine-learning reanalysis of BOUGIE evaluated individualised treatment effects and suggested clinically meaningful heterogeneity (i.e., some patients may benefit while others may not), underscoring the need for better phenotyping of “anatomically” vs “physiologically” difficult intubation and for pre-specified adaptive or enriched trial designs.⁷
• Where guidelines land: ICU intubation guidance historically positions bougie as an adjunct/rescue tool within difficult airway strategies rather than as a default for all first attempts; BOUGIE supports a more selective, context-dependent approach to bougie-first adoption rather than universal mandate.⁸

Summary

• In 1102 analysed ED/ICU patients, bougie-first did not improve first-attempt intubation success compared with a styleted tube (80.4% vs 83.0%; P=0.27).
• Bougie-first was associated with a modestly longer induction-to-intubation time (median +12 seconds) and numerically more severe hypoxaemia (11.0% vs 8.8%).
• Exploratory outcomes (not multiplicity-adjusted) favoured bougie for cardiovascular collapse and 28-day mortality, requiring cautious interpretation.
• Protocol adherence and between-group separation were excellent (bougie used in 98.4% of bougie-assigned first attempts vs 2.3% in stylet-assigned).
• The trial supports selective rather than routine bougie-first use in heterogeneous critical care airways.

Further Reading

Other Trials

• 2018Driver 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.
• 2016Driver BE, Prekker ME, Moore JC, et al. Direct versus video laryngoscopy using the C-MAC for tracheal intubation in the emergency department: a randomized controlled trial. Acad Emerg Med. 2016;23(4):433-439.
• 2016Janz DR, Semler MW, Lentz RJ, et al. Randomized trial of video laryngoscopy for endotracheal intubation of critically ill adults. Crit Care Med. 2016;44(11):1980-1987.
• 2019Casey JD, Janz DR, Russell DW, et al. Bag-mask ventilation during tracheal intubation of critically ill adults. N Engl J Med. 2019;380(9):811-821.
• 2018Janz DR, Semler MW, Joffe AM, et al. A multicenter randomized trial of a checklist for endotracheal intubation of critically ill adults. Chest. 2018;153(4):816-824.

Systematic Review & Meta Analysis

• 2024von Hellmann R, Peters M, Weingart SD, et al. Effect of bougie use on first-attempt success in tracheal intubations: a systematic review and meta-analysis. Ann Emerg Med. 2024;83(2):132-144.
• 2024Wilson C, et al. Bougie or stylet for emergency intubation? A systematic review and meta-analysis. Can J Emerg Med. 2024;26:781-783.
• 2016Buis ML, Maissan IM, Hoeks SE, Klimek M, Stolker RJ. Defining the learning curve for endotracheal intubation using direct laryngoscopy: a systematic review. Resuscitation. 2016;99:63-71.
• 2020Mosier JM, Joshi R, Hypes C, Pacheco G, Valenzuela T, Sakles JC. The physiologically difficult airway. Am J Respir Crit Care Med. 2020;201(7):775-788.
• 2021Heidegger T. Management of the difficult airway. N Engl J Med. 2021;384(19):1836-1847.

Observational Studies

• 2017Driver BE, Dodd KW, Klein LR, et al. The bougie and first-pass success in the emergency department. Ann Emerg Med. 2017;70(4):473-478.e1.
• 2021Latimer AJ, Tan E, Dutta S, et al. Routine use of a bougie improves first-attempt intubation success in the out-of-hospital setting. Ann Emerg Med. 2021;77(3):296-304.
• 2021Russotto V, Myatra SN, Laffey JG, et al. Intubation practices and adverse peri-intubation events in critically ill patients from 29 countries. JAMA. 2021;325(12):1164-1172.
• 2017Alkhouri H, Vassiliadis J, Murray M, et al. Emergency airway management in Australian and New Zealand emergency departments: a multicentre descriptive study of 3710 emergency intubations. Emerg Med Australas. 2017;29(5):499-508.
• 2018Ångerman S, Persson J, Jacobsson J, et al. Protocol for a pre-hospital emergency anaesthesia study comparing video laryngoscopy alone with video laryngoscopy plus a Frova introducer. Anaesthesia. 2018;73(3):348-355.

Guidelines

• 2023Acquisto NM, Mosier JM, Bittner EA, et al. Society of Critical Care Medicine Clinical Practice Guidelines for Rapid Sequence Intubation in the Critically Ill Adult Patient: Executive Summary. Crit Care Med. 2023;51(10):1407-1410.
• 2024Karamchandani K, Nasa P, Jarzebowski M, et al. Tracheal intubation in the physiologically difficult airway: international Delphi consensus recommendations. Intensive Care Med. 2024;50(10):1563-1579.
• 2018Higgs A, McGrath BA, Goddard C, et al. Guidelines for the management of tracheal intubation in critically ill adults. Br J Anaesth. 2018;120(2):323-352.
• 2015Frerk C, Mitchell VS, McNarry AF, et al. Difficult Airway Society 2015 guidelines for management of unanticipated difficult intubation in adults. Br J Anaesth. 2015;115(6):827-848.
• 2016Myatra SN, Ahmed SM, Kundra P, et al. All India Difficult Airway Association 2016 guidelines for tracheal intubation in the intensive care unit. Indian J Anaesth. 2016;60(12):922-930.

Notes

• Hyperangulated video laryngoscope blades were excluded; extrapolation to hyperangulated workflows (where stylet shaping is integral) should be cautious.
• Secondary and exploratory outcomes were not adjusted for multiple comparisons; interpret confidence intervals as descriptive rather than confirmatory.

Overall Takeaway

BOUGIE is a landmark pragmatic airway trial because it challenged the emerging default of “bougie-first” for all critically ill intubations, demonstrating no improvement in first-pass success in a broad ED/ICU population while clarifying potential trade-offs (time and hypoxaemia). It reframed bougie use as a selective strategy—valuable for specific anatomical scenarios and rescue pathways—rather than a universal first-line mandate.

Bibliography

• 1Driver BE, Semler MW, Self WH, et al. Bougie or stylet in patients undergoing intubation emergently (BOUGIE): protocol and statistical analysis plan for a randomised clinical trial. BMJ Open. 2021;11(8):e047790.
• 2Driver 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.
• 3Brenner MJ, McGrath BA, Cook TM. Use of a Bougie vs Endotracheal Tube With Stylet and Successful Intubation on the First Attempt Among Critically Ill Patients Undergoing Tracheal Intubation. JAMA. 2022;327(15):1502-1503.
• 4Kida K, et al. Use of a Bougie vs Endotracheal Tube With Stylet and Successful Intubation on the First Attempt Among Critically Ill Patients Undergoing Tracheal Intubation. JAMA. 2022;327(15):1503.
• 5Driver BE, Prekker ME, Casey JD. Use of a Bougie vs Endotracheal Tube With Stylet and Successful Intubation on the First Attempt Among Critically Ill Patients Undergoing Tracheal Intubation—Reply. JAMA. 2022;327(15):1503-1504.
• 6von Hellmann R, Peters M, Weingart SD, et al. Effect of bougie use on first-attempt success in tracheal intubations: a systematic review and meta-analysis. Ann Emerg Med. 2024;83(2):132-144.
• 7Seitz KP, Sarangarm P, Pallmann P, et al. Individualized treatment effects of bougie versus stylet for successful intubation on first attempt among critically ill patients. Am J Respir Crit Care Med. 2023;207(12):1602-1611.
• 8Higgs A, McGrath BA, Goddard C, et al. Guidelines for the management of tracheal intubation in critically ill adults. Br J Anaesth. 2018;120(2):323-352.