Difficult Airway Prediction by Integrating STOP-BANG Criteria

Enhancing Difficult Airway Prediction in Obese Patients: Integrating STOP-BANG With Additional Airway Assessment Tools

This study is being done to determine the diagnostic accuracy of the STOP-BANG questionnaire in predicting difficult mask ventilation and intubation among obese patients.

During the preoperative assessment, eligible participants will be enrolled in the study. The modified Mallampati score, thyromental distance, mouth opening, and upper lip bite tests will be performed along with STOP-Bang scores.

Later in the operating room, general anesthesia will be given, and bag-mask ventilation and intubation grade will be assessed and recorded. A correlation will be assessed between the difficult airway assessment findings, along with the STOP-BANG score and the bas-mask difficulty scores and intubation grades.

Study Overview

• Status: Recruiting
• Conditions: Intubation; Difficult or Failed; Ventilatory Defect

Detailed Description

After approval of the Ethical Review Committee (ERC), the study will commence. Participants will be selected from the scheduled elective surgical lists of all surgical departments. Written informed consent will be acquired from all study participants. The resident will document demographic variables (age, height, weight, and gender) and STOP-Bang scores during the pre-anesthesia assessment for eligible participants. A STOP-Bang score of ≥ 3 will suggest a higher risk for difficult airway, whereas a score of < 3 will suggest a lower risk. Anesthesia residents under the supervision of a consultant anesthesiologist will record intraoperative observations on a study form. A qualified anesthesia provider performing bag-mask ventilation must have at least three years of anesthesia experience. The primary investigator will gather the questionnaire and intraoperative data form from the trained anesthesiologist. The anesthesiologist managing the airway will be unaware of the STOP-Bang score. Standard monitoring (ECG, non-invasive blood pressure, and peripheral oxygen saturation) will be attached, and baseline readings will be recorded. Pre-oxygenation will be performed for three minutes. Anesthesia will be induced with nalbuphine 100 micrograms/kg and propofol 2 mg/kg until the patient becomes unresponsive to verbal communication; atracurium 0.6 mg/kg will be given after assessing ventilation. Mask ventilation will be carried out for three minutes with the patient's head in the sniffing position. The supervising consultant will decide when to intervene if the primary anesthetist is unable to mask ventilate the patient.

Following three minutes of mask ventilation, the trachea will be intubated using a Macintosh laryngoscope. The endotracheal tube's correct position will be confirmed by monitoring a persistent end-tidal CO₂ waveform, visible chest rise, and bilateral chest auscultation.

• Study Type: Observational
• Enrollment (Estimated): 233

Contacts and Locations

• Study Contact: Name: Syed M Abbas, FCPS; Phone Number: 2193 02199215718; Email: smabbas69@hotmail.com

Study Locations

• Pakistan
  • Sindh
    • Karachi, Sindh, Pakistan, 74200
      • Recruiting
      • Sindh Institute of urology and Transplantation
      • Contact: Syed M Abbas, FCPS; Phone Number: +923331318838; Email: smabbas69@hotmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Non-Probability Sample

Study Population

• Male & Female aged 18-60 years.
• Body mass index 30 or more
• American Society of Anesthesiologists (ASA) status II-III.
• Scheduled for elective surgery under general anesthesia with endotracheal intubation.

Description

Inclusion Criteria:

• Male & Female aged 18-60 years.
• Body mass index 30 or more
• American Society of Anesthesiologists (ASA) status II-III.
• Scheduled for elective surgery under general anesthesia with endotracheal intubation.

Exclusion Criteria:

• Patients' refusal to participate.
• American Society of Anesthesiologists (ASA) IV & V.
• Neuromuscular diseases or facial abnormalities.
• Cardiothoracic, head and neck, or emergency surgery.
• Previously diagnosed with OSA (by polysomnography) will be excluded.
• Any airway-related anatomical deformity (e.g., Down's syndrome).
• History of radiation exposure.
• Patient with mouth opening <2 fingers

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Adequate Bag-Mask Ventilation	When an anesthetized patient is being manually ventilated by an anesthesia bag and a face mask and achieving a tidal volume of 5 ml/kg, it will be called adequate mask ventilation.; Easy if a single anesthesiologist achieves visible adequate chest rise and an end-tidal CO₂ graph.; Moderately difficult, if there is a slight chest rise, a low end-tidal CO₂ graph, but peripheral oxygen saturation is maintained above 97%.; Difficult if there is no visible chest rise, minimal or no end-tidal CO₂ graph, or if peripheral oxygen saturation drops to less than 95% but becomes normal with use of an oral airway (Guedel airway) or a laryngeal mask airway (LMA), or if two anesthesia providers are required for adequate mask ventilation.; Very difficult if peripheral oxygen saturation drops to 90% or less despite the use of airway adjuncts (Guedel airway or LMA).	Only once, after giving general anesthesia but before an endotracheal tube is put in the trachea
Difficult Tracheal Intubation	Difficult tracheal intubation will be defined as, one that requires external laryngeal manipulation, laryngoscopy requiring more than 3 attempts at intubation, intubation requiring nonstandard equipment or approaches, or the inability to intubate at all	Only once, after giving general anesthesia and 3-minute bag-mask ventilation for adequate muscle relaxation effect, then direct laryngoscopy will be performed to put the endotracheal tube in the trachea

Collaborators and Investigators

• Sponsor: Sindh Institute of Urology and Transplantation
• Investigators: Principal Investigator: Syed M Abbas, FCPS, Sindh Institute of urology and Transplantation

Study record dates

Study Major Dates

• Study Start (Actual): March 9, 2026
• Primary Completion (Estimated): September 8, 2026
• Study Completion (Estimated): September 8, 2026

Study Registration Dates

• First Submitted: March 19, 2026
• First Submitted That Met QC Criteria: March 19, 2026
• First Posted (Actual): March 25, 2026

Study Record Updates

• Last Update Posted (Actual): March 25, 2026
• Last Update Submitted That Met QC Criteria: March 19, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Laryngoscopy; General Anesthesia; Ventilation of lungs; Bag-mask
• Other Study ID Numbers: SIUT-ERC-2025/A-587

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Data will not be shared

Drug and device information, study documents

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