Ventilatory DefectNCT07493356
Difficult Airway Prediction by Integrating STOP-BANG Criteria
An observational study of Ventilatory Defect and Intubation; Difficult or Failed, run by Sindh Institute of Urology and Transplantation at 1 site in Pakistan.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 to 60 years
- Conditions the study is for
- Ventilatory Defect, Intubation; Difficult or Failed
- How many people
- 233 participants
- Where
- 1 sitePakistan
- Study dates
- 9 Mar 2026to 8 Sep 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 60 years
- All sexes
- Adult
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.
Who may be able to join
- 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.
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Pakistan1 site, 1 recruiting
- Recruiting
Sindh Institute of Urology and Transplantation
Karachi, Sindh, 74200
Syed M Abbas, FCPS, +923331318838, smabbas69@hotmail.com
About this study
Official title: 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.
Read the 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.
- Keywords
- Laryngoscopy, Ventilation of lungs, Bag-mask, General Anesthesia
What is being measured
The primary outcome is the main question the study is designed to answer.
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).
Measured: 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
Measured: 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
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Mar 2026
- Study start9 Mar 2026
- Primary completion8 Sep 2026 (estimated)
- Study completion8 Sep 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Ventilatory DefectStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Enrolment
- 233 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Sindh Institute of Urology and Transplantation
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Syed Muhammad Abbas, Sindh Institute of Urology and Transplantation
- Investigators
- Syed M Abbas, FCPS, Principal investigator, Sindh Institute of Urology and Transplantation
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07493356
- Sponsor's protocol ID
- SIUT-ERC-2025/A-587
- Status last verified
- Mar 2026
- First submitted
- 19 Mar 2026
- Last updated
- 25 Mar 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Data will not be shared
Study at a glance
From the registry record, last updated by the sponsor on 25 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Enhancing Difficult Airway Prediction in Obese Patients: Integrating STOP-BANG With Additional Airway Assessment Tools
- ClinicalTrials.gov ID
- NCT07493356
- Acronym / sponsor ID
- SIUT-ERC-2025/A-587
- Keywords
- Laryngoscopy, Ventilation of lungs, Bag-mask, General Anesthesia
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 233 participants (estimated)
- Lead sponsor
- Sindh Institute of Urology and TransplantationUniversity, hospital or other
- Study start
- 9 Mar 2026 (actual)
- Primary completion
- 8 Sep 2026 (estimated)
- Study completion
- 8 Sep 2026 (estimated)
- First posted
- 25 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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 design
- Observational model
- Cohort
- Time perspective
- Cross-sectional
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Age groups
- Adult
- 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.
Key inclusion criteria (4 listed)
- 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.
Key exclusion criteria (8 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Adequate Bag-Mask Ventilation
Time frame: Only once, after giving general anesthesia but before an endotracheal tube is put in the trachea
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).
Difficult Tracheal Intubation
Time frame: 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
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
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Mar 2026.
- Individual participant dataSharing planned: No. Data will not be shared
Related trials for Ventilatory Defect
Recruiting
Effect of Aerobic and Resistance Exercise on Quarry Workers
Ventilatory Defect, Occupational Lung Diseases
RecruitingObservational study
Quantitation and Spatial Registration of Airways Dysfunction With Dynamic 19F MRI in Cystic Fibrosis
Cystic Fibrosis, Ventilatory Defect
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Syed M Abbas, FCPS principal investigator
Sindh Institute of Urology and Transplantation
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Ventilatory Defect and Intubation; Difficult or Failed, run by Sindh Institute of Urology and Transplantation at 1 site in Pakistan.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 25 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Pakistan. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Syed M Abbas, FCPS (02199215718 ext. 2193, smabbas69@hotmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Adequate Bag-Mask Ventilation (time frame: Only once, after giving general anesthesia but before an endotracheal tube is put in the trachea). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 25 Mar 2026.