Classification and Prediction of Difficult Awake Tracheal Intubation With Flexible Bronchoscopes (AirWake)

Airway management problems are key drivers for anesthesia-related adverse events. Awake tracheal intubation using flexible bronchoscopes with preserved spontaneous breathing (ATI:FB) is a recommended technique to manage difficult tracheal intubation in anesthesia, intensive care and emergency medicine. However, a prospective developed classification for this type of airway management is lacking. Due to the absence of a specifically tailored, validated classification for awake intubation with flexible bronchoscopes, many airway operators and institutions use classification tools that were originally developed for direct laryngoscopy, such as the percentage of glottic opening (POGO) score or Cormack-Lehane classification, although their diagnostic performance for the classification of ATI:FB is unknown. This prospective model development and validation study aims to develop two multivariable prediction models: a diagnostic prediction model to classify difficult ATI:FB after ATI:FB has been performed and a second prognostic prediction model to predict the risk for difficult ATI:FB before ATI:FB is performed. An additional aim is to develop a machine learning algorithm to evaluate ATI:FB.

Study Overview

• Status: Recruiting
• Conditions: Airway Management; Anesthesia; Bronchoscopy; Intubation, Intratracheal; Endoscopes

• Study Type: Observational
• Enrollment (Estimated): 313

Contacts and Locations

• Study Contact: Name: Martin Petzoldt, MD, FEAMS; Phone Number: 04915222815932; Email: m.petzoldt@uke.de
• Study Contact Backup: Name: Vera Köhl, MD; Email: v.koehl@uke.de

Study Locations

• Germany
  • Hamburg, Germany, 20246
    • Recruiting
    • University Medical Center Hamburg-Eppendorf
    • Contact: Martin Petzoldt, MD; Phone Number: 04915222815932; Email: m.petzoldt@uke.de

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

Patients with anticipated difficult airways scheduled for surgery with general anaesthesia and tracheal intubation at a single study center

Description

Inclusion Criteria:

• Patients with an anticipated difficult airways scheduled for ATI:FB
• Consent by the patient
• Minimum 18 years of age

Exclusion Criteria:

• Patients not scheduled for ATI:FB
• Pregnant or breastfeeding patients
• Consent not given by the patient

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Difficult awake flexible bronchoscopic intubation	Difficult airway alert issued by the airway operator following ATI:FB	1 hour

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of intubation attempts	Observed during airway management	1 hour
First attempt success	Number of participants with successful ATI:FB with only one attempt	1 hour
Number of bronchoscopy attempts	Observed during airway management	1 hour
Successful ATI:FB	Number of participants with successful ATI:FB	1 hour
Successful bronchoscopy	Number of participants with successful bronchoscopy	1 hour
Successful tube placement	Number of participants with successful tracheal tube placement	1 hour
Coversion to another type of airway management	Observed during airway management	1 hour
Conversion from transnasal to transoral bronchoscopy or vice versa	Observed during airway management	1 hour
Percentage of glottic opening	Grading of the best view obtained during laryngoscopy (%)	1 hour
Glottic view	Grading of the best view obtained using landmarks (6-stages)	1 hour
Time to best glottic view	Recorded during airway management (seconds)	1 hour
Time to intubation	Recorded during airway management (seconds)	1 hour
Lowest oxygen saturation	Measured during airway management (%)	1 hour
Endtidal CO2	First value measured after intubation (mmHg)	1 hour
Airway obstructions requiring external manipulation	Observed during airway management	1 hour
Hypoxia	Observed during airway management	1 hour
Cardiovascular event requiring intervention (hypotension/bradycardia)	Relevant hypotension or bradycardia observed during airway management	1 hour
Cardiovascular event requiring intervention (hypertension, tachycardia)	Relevant hypertension or tachycardia observed during airway management	1 hour
Additional manouvers and adjuncts used	Observed during airway management	1 hour
Patient discomfort during ATI:FB	Observed during airway management	1 hour
Airway-related complications	Observed during airway management	1 hour
Anaesthesia alert card issued	Anaesthesia alert card issued by the airway operator	1 hour
Recommendation for future airway management	Recommendation documented by the airway operator after airway management	1 hour
Richmond agitation-sedation Scale	Observed during airway management (scale form -4 to 5 points; lower values indicate deeper sedation)	1 hour
Subjective rating of difficulty of sedation, topicalisation, bronchoscopy and tube placement	Rating of the airway operator (visual analog scales [0-100]; lower values indicate better conditions)	1 hour
Preparation time	Recorded during airway management	1 hour

Collaborators and Investigators

• Sponsor: Universitätsklinikum Hamburg-Eppendorf
• Investigators: Principal Investigator: Martin Petzoldt, MD, FEAMS, University Medical Center Hamburg-Eppendorf: Universitatsklinikum Hamburg-Eppendorf; Principal Investigator: Vera Köhl, MD, University Medical Center Hamburg-Eppendorf: Universitatsklinikum Hamburg-Eppendorf

Publications and helpful links

General Publications

• Dohrmann T, Gutsche N, Kramer R, Zeidler EM, Roher K, Wunsch VA, Dankert A, Krause L, Zollner C, Sasu PB, Petzoldt M. Prospective development and validation of a universal classification for paediatric videolaryngoscopic tracheal intubation: the PeDiAC score. Anaesthesia. 2024 Nov;79(11):1201-1211. doi: 10.1111/anae.16394. Epub 2024 Aug 7.
• Barclay-Steuart A, Grosshennig HL, Sasu P, Wunsch VA, Stadlhofer R, Berger J, Stark M, Sehner S, Zollner C, Petzoldt M. Transnasal Videoendoscopy for Preoperative Airway Risk Stratification: Development and Validation of a Multivariable Risk Prediction Model. Anesth Analg. 2023 Jun 1;136(6):1164-1173. doi: 10.1213/ANE.0000000000006418. Epub 2023 Apr 19.
• Kohse EK, Siebert HK, Sasu PB, Loock K, Dohrmann T, Breitfeld P, Barclay-Steuart A, Stark M, Sehner S, Zollner C, Petzoldt M. A model to predict difficult airway alerts after videolaryngoscopy in adults with anticipated difficult airways - the VIDIAC score. Anaesthesia. 2022 Oct;77(10):1089-1096. doi: 10.1111/anae.15841. Epub 2022 Aug 25.

Study record dates

Study Major Dates

• Study Start (Actual): April 30, 2025
• Primary Completion (Estimated): January 31, 2026
• Study Completion (Estimated): January 31, 2026

Study Registration Dates

• First Submitted: April 22, 2025
• First Submitted That Met QC Criteria: April 29, 2025
• First Posted (Actual): May 1, 2025

Study Record Updates

• Last Update Posted (Actual): May 6, 2025
• Last Update Submitted That Met QC Criteria: May 1, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Keywords: Classification; Airway management; Respiratory system; Flexible endoscopy guided intubation; Fibroptic guided intubation; Laryngeal diseases; Health records
• Other Study ID Numbers: 2025-101447-BO-ff

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No