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Examining the Effects of Anthropometric Measurements on Difficult Airway Prediction

Examining the Effects of the Stop-Bang Scoring Model, Anthropometric Measurements, and Head Dimensions on Difficult Airway Prediction

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT07077317
Enrollment
1044
Registered
2025-07-22
Start date
2025-08-13
Completion date
2025-11-11
Last updated
2025-11-25

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Airway Management, Difficult Airway, Difficult Airway Intubation

Keywords

mask ventilation, intubation, Cormack-Lehane, Airway Assessment

Brief summary

Airway-related complications are among the leading causes of anesthesia-associated morbidity and mortality. Therefore, the ability to predict difficult mask ventilation, laryngoscopy, and intubation before induction is essential to ensure proper preparation in patients at risk and avoid unnecessary airway manipulations in low-risk individuals. While numerous studies have focused on predicting difficult intubation, most have limited sample sizes and do not consider postoperative critical respiratory events. In this prospective observational clinical study, we aim to investigate the relationship between commonly used preoperative airway assessment tools-including anthropometric measurements, Mallampati score, and the STOP-Bang questionnaire for obstructive sleep apnea-and the incidence of difficult mask ventilation, difficult laryngoscopy (Cormack-Lehane grading), difficult intubation, and critical respiratory events in the postoperative period. The study will include adult patients (≥18 years) classified as ASA I-IV undergoing surgery under general anesthesia with endotracheal intubation. Data will be collected preoperatively, intraoperatively, and in the post-anesthesia care unit (PACU) by experienced anesthesia personnel. Postoperative critical respiratory events are defined as unexpected hypoxemia, hypoventilation, reintubation, or interventions required for upper/lower airway obstruction.

Detailed description

Difficult airway management remains one of the most significant challenges in clinical anesthesia, often leading to severe complications such as hypoxemia, aspiration, and even cardiac arrest. Despite various clinical predictors, no single assessment method reliably identifies all patients at risk. This prospective, observational study aims to comprehensively evaluate the association between preoperative airway assessment parameters and both intraoperative airway difficulty and postoperative critical respiratory events. The preoperative assessment will include demographic characteristics, comorbidities, ASA classification, Mallampati score, and detailed anthropometric airway measurements (neck circumference, thyromental distance, sternomental distance, interincisor gap, head dimensions, presence of beard/dentition, and neck mobility). Additionally, the STOP-Bang questionnaire will be administered to assess the risk of obstructive sleep apnea (OSA). During induction and airway management, mask ventilation difficulty will be graded, Cormack-Lehane score during laryngoscopy will be recorded, and intubation will be evaluated in terms of the number of attempts and need for adjunctive devices (stylet, bougie, fiberoptic bronchoscope, videolaryngoscope, etc.). In the postoperative phase, patients will be monitored for critical respiratory events including unexpected hypoxemia (SpO₂ \<90%), hypoventilation (RR \<8/min or PaCO₂ \>50 mmHg), reintubation, and any interventions (e.g., airway support, bronchodilators, cold mist, etc.) required for upper or lower airway obstruction. The outcomes of this study may help refine preoperative screening protocols and contribute to the development of risk-based airway management strategies aimed at improving patient safety.

Interventions

OTHERAirway Assessment Using Standard Clinical Tools

Preoperative airway evaluation using routine physical measurements (e.g., Mallampati score, neck circumference, STOP-Bang questionnaire), and intraoperative/postoperative observation of airway-related parameters.

Sponsors

Kutahya Health Sciences University
Lead SponsorOTHER

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Age ≥ 18 years, * ASA Physical Status I, II, III or IV, * Undergoing elective surgery under general anesthesia with endotracheal intubation, * Written informed consent provided

Exclusion criteria

* History of head and neck surgery or trauma causing anatomical deformity, * Known congenital or acquired airway abnormality, * Cervical spine surgery or instability, * Age \< 18 years

Design outcomes

Primary

MeasureTime frameDescription
Incidence of Difficult Mask VentilationIntraoperative (during anesthesia induction)Evaluation of mask ventilation using a standard difficulty grading scale. 1. Mask Ventilation Successful 2. Mask Ventilation Requires Oral Airway 3. Mask Ventilation Requires Oral Airway And Assistant (Two Hands) 4. Mask Ventilation Failure
Incidence of Difficult LaryngoscopyIntraoperative (during laryngoscopy)Cormack-Lehane grade III-IV views considered difficult laryngoscopy.
Incidence of Difficult IntubationIntraoperative (during intubation)Defined as more than two attempts, or the requirement of adjuncts such as bougie, videolaryngoscope, or fiberoptic bronchoscope.
Occurrence of Postoperative Critical Respiratory EventsWithin the first 2 hours postoperatively (in PACU)Events include unexpected hypoxemia (SpO₂ \< 90%), hypoventilation (RR \< 8/min or PaCO₂ \> 50 mmHg), reintubation, and active interventions for airway obstruction.

Secondary

MeasureTime frameDescription
Correlation Between Anthropometric Measurements and Critical Respiratory EventsPreoperative to postoperative periodInvestigate associations between variables such as neck circumference, interincisor gap, or sternomental distance with postoperative respiratory complications.
Correlation Between Anthropometric Measurements and Difficult Airway ManagementPreoperative to intraoperative (induction period of anesthesia)Investigate associations between variables such as neck circumference, interincisor gap, or sternomental distance, head dimensions, with difficult mask ventilation or difficult intubation.
Correlation Between STOP-Bang Score and Difficult Airway IncidencePreoperative through intraoperative periodEvaluate predictive value of high STOP-Bang scores (≥3) for difficult mask ventilation, laryngoscopy, and intubation.

Countries

Turkey (Türkiye)

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026