Difficult AirwayOB-DIFF-AIRWAYNCT07340346
Prediction of Difficult Airway in Cesarean Section Using Preoperative Airway Assessment Tests
An observational study of Difficult Airway and Airway Management, run by Akdeniz University Hospital at 1 site in Turkey (Türkiye).
Trial summary
This observational study (OB-DIFF-AIRWAY: Obstetric Difficult Airway Study) aimed to evaluate the accuracy of commonly used preoperative airway assessment tests in predicting difficult airway management in obstetric patients undergoing cesarean section. Read more about this study
- Who is it for?
- Ages 18 years and older, women only
- Conditions the study is for
- Difficult Airway, Airway Management, Obstetric Anesthesia
- How many people
- 546 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 23 Aug 2023to 23 Aug 2024
- Phase
- Observational
- Are there results?
- None posted in the registry
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 years and older
- Women only
- No healthy volunteers
- Adult, Older adult
Study population: Adult pregnant women aged 18 years and older who underwent elective or urgent cesarean section at a tertiary university hospital. All participants received standard preoperative airway assessment as part of routine anesthetic care.
Who may be able to join
- Adult obstetric patients aged 18 years or older
- Scheduled for elective or urgent cesarean section
- Undergoing routine preoperative airway assessment
- Provided written informed consent
Who cannot join
- Known congenital or acquired airway pathology
- History of difficult airway requiring advanced airway techniques
- Emergency situations requiring immediate airway management without standard preoperative assessment
- Incomplete or missing airway assessment data
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Akdeniz University Hospital
Antalya, Türkiye, 07000
About this study
Official title: Evaluation of the Reliability of Preoperative Airway Assessment Tests in Predicting Difficult Airway Management in Obstetric Patients Undergoing Cesarean Section
This observational study (OB-DIFF-AIRWAY: Obstetric Difficult Airway Study) aimed to evaluate the accuracy of commonly used preoperative airway assessment tests in predicting difficult airway management in obstetric patients undergoing cesarean section. Difficult airway remained a significant cause of anesthesia-related complications, particularly in pregnant patients due to physiological and anatomical changes.
Adult pregnant women scheduled for elective or urgent cesarean section underwent standard preoperative airway assessment, including Mallampati classification, thyromental distance, interincisor distance, neck circumference, and other routine clinical evaluations. Airway management during anesthesia was performed according to standard clinical practice. No additional intervention was applied for the purpose of the study.
The relationship between preoperative airway assessment findings and actual airway management difficulty was analyzed. The results of this study may help improve preoperative airway evaluation strategies and enhance patient safety in obstetric anesthesia.
Read the detailed description
Difficult airway management is one of the most critical challenges in anesthetic practice and is associated with increased morbidity and mortality. Obstetric patients represent a particularly high-risk population due to pregnancy-related physiological changes such as airway edema, weight gain, reduced functional residual capacity, and increased oxygen consumption. Despite routine use of various preoperative airway assessment tests, their predictive value in obstetric patients remains controversial.
This prospective observational study was conducted to evaluate the reliability of commonly used preoperative airway assessment tests in predicting difficult airway management in patients undergoing cesarean section. The study was performed at Akdeniz University Hospital between August 23, 2023, and August 23, 2024.
Adult obstetric patients scheduled for elective or urgent cesarean section under anesthesia were included. Patients with known airway pathology, prior difficult airway history requiring advanced airway techniques, or incomplete airway assessment data were excluded according to predefined criteria.
Preoperative airway assessment was performed as part of routine anesthetic evaluation and included Mallampati classification, thyromental distance, interincisor distance, neck circumference, and other standard clinical parameters. No additional procedures or interventions were introduced for research purposes. Anesthetic management and airway techniques were determined by the attending anesthesiologist in accordance with institutional standards.
Airway management difficulty was recorded intraoperatively based on predefined clinical criteria, including difficulty with mask ventilation, laryngoscopy, or tracheal intubation. The association between preoperative airway assessment findings and observed airway difficulty was analyzed using appropriate statistical methods. Difficult airway management was defined as the presence of at least one of the following predefined intraoperative criteria:
difficult mask ventilation (Han classification ≥ 3), difficult laryngoscopy (Cormack-Lehane grade III-IV), or failure of tracheal intubation on the first attempt.
Patients were enrolled using a consecutive non-probability sampling approach, including all eligible obstetric patients undergoing cesarean delivery during the study period.
The sample size was determined by the consecutive inclusion of all eligible patients undergoing cesarean delivery at the study center during the predefined study period.
The primary objective of the study was to assess the predictive value of individual and combined airway assessment tests for difficult airway management in obstetric patients. Secondary objectives included identifying potential risk factors associated with airway difficulty and evaluating the overall incidence of difficult airway in the study population.
The findings of this study are expected to contribute to improved preoperative airway evaluation and risk stratification in obstetric anesthesia, thereby enhancing patient safety and clinical outcomes.
- Conditions
- Difficult Airway, Airway Management, Obstetric Anesthesia
- Being tested
- No intervention (observational study)
- Keywords
- Preoperative Airway Assessment, Mallampati Score, Difficult Intubation, Obstetric Patients
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
No intervention (observational study)Other
This is an observational study. No experimental intervention was assigned. All assessments and airway management procedures were performed as part of routine clinical practice.
| Study group | Role | What they receive |
|---|---|---|
| Obstetric Patients Undergoing Cesarean Section | Adult obstetric patients undergoing elective or urgent cesarean section who received standard preoperative airway assessment as part of routine anesthetic care. Airway management was performed according to institutional clinical practice without any study-related intervention. Receives: Other: No intervention (observational study) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Prediction of Difficult Airway Using Preoperative Airway Assessment Tests
The primary outcome is the ability of preoperative airway assessment tests to predict difficult airway management during cesarean delivery.
Predictive performance was evaluated using sensitivity, specificity, positive and negative predictive values, and the area under the receiver operating characteristic (ROC) curve (AUC).
Difficult airway was defined based on predefined intraoperative criteria such as difficulty in mask ventilation, difficult laryngoscopy, or difficult tracheal intubation as assessed by the attending anesthesiologist.
Measured: During anesthesia induction
Secondary outcomes (2)
Incidence of Difficult Airway in Obstetric Patients
The incidence of difficult airway management among obstetric patients undergoing cesarean section was evaluated based on predefined clinical criteria.
Measured: During anesthesia induction
Association Between Individual Airway Assessment Tests and Difficult Airway
The association between individual preoperative airway assessment tests and the occurrence of difficult airway management was analyzed to identify potential risk factors.
Measured: During anesthesia induction
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Jan 2026
- Study start23 Aug 2023
- Primary completion23 Aug 2024
- Study completion23 Aug 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Difficult AirwayStudies 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
- Prospective
- Enrolment
- 546 participants (actual)
Sponsor and investigators
- Lead sponsor
- Akdeniz University Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, ALİ DEMİRTAŞ, Akdeniz University Hospital
- Investigators
- ALİ DEMİRTAŞ, Principal investigator, Akdeniz University Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07340346
- Sponsor's protocol ID
- Difficult Airway in Cesarean
- Acronym
- OB-DIFF-AIRWAY
- Status last verified
- Jan 2026
- First submitted
- 6 Jan 2026
- Last updated
- 14 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Mushambi MC, Jaladi S. Airway management and training in obstetric anaesthesia. Curr Opin Anaesthesiol. 2016 Jun;29(3):261-7. doi: 10.1097/ACO.0000000000000309.
PubMed 26844863Freedman RL, Lucas DN. MBRRACE-UK: saving lives, improving mothers' care - implications for anaesthetists. Int J Obstet Anesth. 2015 May;24(2):161-73. doi: 10.1016/j.ijoa.2015.03.004. Epub 2015 Mar 14.
PubMed 25841640McKeen DM, George RB, O'Connell CM, Allen VM, Yazer M, Wilson M, Phu TC. Difficult and failed intubation: Incident rates and maternal, obstetrical, and anesthetic predictors. Can J Anaesth. 2011 Jun;58(6):514-24. doi: 10.1007/s12630-011-9491-9. Epub 2011 Apr 7.
PubMed 21472485
Study at a glance
From the registry record, last updated by the sponsor on 14 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of the Reliability of Preoperative Airway Assessment Tests in Predicting Difficult Airway Management in Obstetric Patients Undergoing Cesarean Section
- ClinicalTrials.gov ID
- NCT07340346
- Acronym / sponsor ID
- OB-DIFF-AIRWAY / Difficult Airway in Cesarean
- Conditions
- Difficult Airway, Airway Management, Obstetric Anesthesia
- Keywords
- Preoperative Airway Assessment, Mallampati Score, Difficult Intubation, Obstetric Patients
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 546 participants (actual)
- Lead sponsor
- Akdeniz University HospitalUniversity, hospital or other
- Study start
- 23 Aug 2023 (actual)
- Primary completion
- 23 Aug 2024 (actual)
- Study completion
- 23 Aug 2024 (actual)
- First posted
- 14 Jan 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 observational study (OB-DIFF-AIRWAY: Obstetric Difficult Airway Study) aimed to evaluate the accuracy of commonly used preoperative airway assessment tests in predicting difficult airway management in obstetric patients undergoing cesarean section. Difficult airway remained a significant cause of anesthesia-related complications, particularly in pregnant patients due to physiological and anatomical changes.
Adult pregnant women scheduled for elective or urgent cesarean section underwent standard preoperative airway assessment, including Mallampati classification, thyromental distance, interincisor distance, neck circumference, and other routine clinical evaluations. Airway management during anesthesia was performed according to standard clinical practice. No additional intervention was applied for the purpose of the study.
The relationship between preoperative airway assessment findings and actual airway management difficulty was analyzed. The results of this study may help improve preoperative airway evaluation strategies and enhance patient safety in obstetric anesthesia.
Detailed description
Difficult airway management is one of the most critical challenges in anesthetic practice and is associated with increased morbidity and mortality. Obstetric patients represent a particularly high-risk population due to pregnancy-related physiological changes such as airway edema, weight gain, reduced functional residual capacity, and increased oxygen consumption. Despite routine use of various preoperative airway assessment tests, their predictive value in obstetric patients remains controversial.
This prospective observational study was conducted to evaluate the reliability of commonly used preoperative airway assessment tests in predicting difficult airway management in patients undergoing cesarean section. The study was performed at Akdeniz University Hospital between August 23, 2023, and August 23, 2024.
Adult obstetric patients scheduled for elective or urgent cesarean section under anesthesia were included. Patients with known airway pathology, prior difficult airway history requiring advanced airway techniques, or incomplete airway assessment data were excluded according to predefined criteria.
Preoperative airway assessment was performed as part of routine anesthetic evaluation and included Mallampati classification, thyromental distance, interincisor distance, neck circumference, and other standard clinical parameters. No additional procedures or interventions were introduced for research purposes. Anesthetic management and airway techniques were determined by the attending anesthesiologist in accordance with institutional standards.
Airway management difficulty was recorded intraoperatively based on predefined clinical criteria, including difficulty with mask ventilation, laryngoscopy, or tracheal intubation. The association between preoperative airway assessment findings and observed airway difficulty was analyzed using appropriate statistical methods. Difficult airway management was defined as the presence of at least one of the following predefined intraoperative criteria:
difficult mask ventilation (Han classification ≥ 3), difficult laryngoscopy (Cormack-Lehane grade III-IV), or failure of tracheal intubation on the first attempt.
Patients were enrolled using a consecutive non-probability sampling approach, including all eligible obstetric patients undergoing cesarean delivery during the study period.
The sample size was determined by the consecutive inclusion of all eligible patients undergoing cesarean delivery at the study center during the predefined study period.
The primary objective of the study was to assess the predictive value of individual and combined airway assessment tests for difficult airway management in obstetric patients. Secondary objectives included identifying potential risk factors associated with airway difficulty and evaluating the overall incidence of difficult airway in the study population.
The findings of this study are expected to contribute to improved preoperative airway evaluation and risk stratification in obstetric anesthesia, thereby enhancing patient safety and clinical outcomes.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Obstetric Patients Undergoing Cesarean Section | – | Other: No intervention (observational study)Adult obstetric patients undergoing elective or urgent cesarean section who received standard preoperative airway assessment as part of routine anesthetic care. Airway management was performed according to institutional clinical practice without any study-related intervention. |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Adult pregnant women aged 18 years and older who underwent elective or urgent cesarean section at a tertiary university hospital. All participants received standard preoperative airway assessment as part of routine anesthetic care.
Key inclusion criteria (4 listed)
- Adult obstetric patients aged 18 years or older
- Scheduled for elective or urgent cesarean section
- Undergoing routine preoperative airway assessment
- Provided written informed consent
Key exclusion criteria (4 listed)
- Known congenital or acquired airway pathology
- History of difficult airway requiring advanced airway techniques
- Emergency situations requiring immediate airway management without standard preoperative assessment
- Incomplete or missing airway assessment data
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| No intervention (observational study)This is an observational study. No experimental intervention was assigned. All assessments and airway management procedures were performed as part of routine clinical practice. | Other | Obstetric Patients Undergoing Cesarean Section |
Primary outcome
Prediction of Difficult Airway Using Preoperative Airway Assessment Tests
Time frame: During anesthesia induction
The primary outcome is the ability of preoperative airway assessment tests to predict difficult airway management during cesarean delivery. Predictive performance was evaluated using sensitivity, specificity, positive and negative predictive values, and the area under the receiver operating characteristic (ROC) curve (AUC). Difficult airway was defined based on predefined intraoperative criteria such as difficulty in mask ventilation, difficult laryngoscopy, or difficult tracheal intubation as assessed by the attending anesthesiologist.
2 secondary outcomes
Incidence of Difficult Airway in Obstetric Patients
Time frame: During anesthesia induction
Association Between Individual Airway Assessment Tests and Difficult Airway
Time frame: During anesthesia induction
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Jan 2026.
- Background: PubMed 26844863Mushambi MC, Jaladi S. Airway management and training in obstetric anaesthesia. Curr Opin Anaesthesiol. 2016 Jun;29(3):261-7. doi: 10.1097/ACO.0000000000000309.
- Background: PubMed 25841640Freedman RL, Lucas DN. MBRRACE-UK: saving lives, improving mothers' care - implications for anaesthetists. Int J Obstet Anesth. 2015 May;24(2):161-73. doi: 10.1016/j.ijoa.2015.03.004. Epub 2015 Mar 14.
- Background: PubMed 21472485McKeen DM, George RB, O'Connell CM, Allen VM, Yazer M, Wilson M, Phu TC. Difficult and failed intubation: Incident rates and maternal, obstetrical, and anesthetic predictors. Can J Anaesth. 2011 Jun;58(6):514-24. doi: 10.1007/s12630-011-9491-9. Epub 2011 Apr 7.
- Individual participant dataSharing planned: No
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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. This study is not recruiting at the moment.
ALİ DEMİRTAŞ principal investigator
Akdeniz University Hospital
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 Difficult Airway and Airway Management, run by Akdeniz University Hospital at 1 site in Turkey (Türkiye).
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 4 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: finished, as of the sponsor's last update on 14 Jan 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 Turkey (Türkiye). 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Prediction of Difficult Airway Using Preoperative Airway Assessment Tests (time frame: During anesthesia induction). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07340346, which also lists 3 linked publications.
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 14 Jan 2026.