Difficult Mask VentilationTADMVNCT07204223
Tulip Airway in Difficult Mask Ventilation (TADMV)
A study testing Tulip Airway and Guedel Airway in people with Difficult Mask Ventilation and Airway Devices, run by Ayse Zeynep Turan Civraz at 1 site in Turkey (Türkiye).
Trial summary
During surgery, right after anesthesia is given, the first step to help the patient breathe is to provide breathing support with a mask. This step is very important because if there is a problem with mask ventilation, the anesthesia team must quickly use other methods to help the patient breathe. Read more about this study
- Who is it for?
- Ages 18 to 75 yearsHealthy volunteers can take part
- Conditions the study is for
- Difficult Mask Ventilation, Airway Devices
- What is being tested?
- Tulip Airway and Guedel Airway
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Oct 2025to 31 Aug 2026
- Phase
- Interventional
- 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 75 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Patients aged between 18 and 75 years
- Patients scheduled for elective surgery under general anesthesia
- Patients with at least two risk factors for difficult mask ventilation, including:
- Age over 55 years
- Presence of beard
- Edentulism (missing teeth)
Show all 12Show fewer
- Obesity (Body Mass Index (BMI) ≥ 30 kg/m²)
- History of obstructive sleep apnea syndrome (OSAS) or snoring
- Neck circumference > 43 cm
- Retrognathia (small jaw structure)
- Patients classified as American Society of Anesthesiologist (ASA) physical status 1, 2, or 3
- Patients who provide informed consent
Who cannot join
- Pregnant or breastfeeding women
- Patients with a history of airway surgery (e.g., tracheostomy, maxillofacial surgery)
- Patients with severe cardiopulmonary diseases (e.g., advanced Chronic obstructive Pulmonary Disease (COPD), pulmonary hypertension, severe heart failure)
- Patients with craniofacial anomalies or significant anatomical airway deformities
- Patients requiring emergency surgery
- Patients with gastroesophageal reflux disease (GERD) and high risk of aspiration
- Patients with active upper respiratory tract infection
- Patients with a history of difficult intubation
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Bedirhan Günel, MD contact
Turkey (Türkiye)1 site, 1 recruiting
- Recruiting
Kocaeli City Hospital
İzmit, Kocaeli, 41060
Ayşe Z Turan Cıvraz, Assoc. Prof., +905054695850, ayse.zeynep@gmail.com
About this study
Official title: Comparison of the Tulip Airway and the Guedel Airway in Anticipated Difficult Mask Ventilation: A Prospective, Randomized, Controlled Crossover Trial
During surgery, right after anesthesia is given, the first step to help the patient breathe is to provide breathing support with a mask. This step is very important because if there is a problem with mask ventilation, the anesthesia team must quickly use other methods to help the patient breathe.
For some people, mask ventilation can be more difficult. Factors such as older age, having a beard, missing teeth, being overweight, sleep apnea, or certain facial shapes can make this process harder.
Read more
To make mask ventilation easier, special devices placed in the mouth are used. The most common one is called the Guedel airway. In recent years, a new device called the Tulip airway has also been introduced. The shape and features of the Tulip airway are designed to make breathing support easier.
In this study, we will compare the Tulip airway and the Guedel airway in patients who are expected to have more difficult mask ventilation. Our goal is to find out which device makes it easier and safer to help patients breathe.
Read the detailed description
The first step in airway management following anesthesia induction is the period of bag-mask ventilation. This step is the most critical phase of airway management because, if mask ventilation fails, the anesthesiologist must make a life-saving decision for the patient. Bag-mask ventilation is a technical skill acquired over time; therefore, difficulty in mask ventilation may be related to either the provider or the patient. According to the literature, the incidence of difficult mask ventilation varies between 0.08% and 15% in different studies.
The American Society of Anesthesiologists (ASA) defines difficult mask ventilation as inadequate mask or supraglottic airway (SGA) ventilation, excessive air leakage, or excessive resistance to airflow during inspiration or expiration. Signs of inadequate ventilation include, but are not limited to, absent or insufficient chest movement, absent or diminished breath sounds, auscultatory signs of severe obstruction, cyanosis, gastric insufflation or distension, decreased or inadequate oxygen saturation (SpO₂), absence or inadequacy of end-tidal carbon dioxide (EtCO₂), absence or inadequacy of expiratory gas flow on spirometry, and hemodynamic changes associated with hypoxemia or hypercarbia (e.g., hypertension, tachycardia, arrhythmia).
Predictors of difficult mask ventilation include age over 55 years, the presence of a beard, poor mask fit due to secretions, edentulism, a history of snoring or obstructive sleep apnea syndrome (OSAS), and obesity. In anesthesia practice, when faced with difficult mask ventilation, various maneuvers, two-hand techniques, and adjunct airway devices are employed. Among these devices are various oral airways, the most common of which is the Guedel airway.
In recent years, new oral airway devices have been introduced as alternatives to the Guedel airway. The Tulip airway is a novel oral airway that is longer than the Guedel airway, equipped with a cuff, and features a connector that allows attachment to the breathing circuit. These characteristics enable it to be secured within the oral cavity via its cuff, and connection to the breathing circuit allows for airway management that may be more comfortable for the anesthesiologist compared to two-handed mask control.
The superiority of the Tulip airway over the Guedel airway has been demonstrated in patients with cervical spine injury, in edentulous manikins, and in patients undergoing general anesthesia. However, it has not been studied in patients with anticipated difficult mask ventilation. The aim of our study is to investigate whether the Tulip airway provides superior performance to the classical Guedel airway during the mask ventilation phase in patients with anticipated difficult mask ventilation. We hypothesize that the use of the Tulip airway in such patients will improve respiratory parameters and reduce the risk of complications during mask ventilation.
- Conditions
- Difficult Mask Ventilation, Airway Devices
- Being tested
- Tulip Airway, Guedel Airway
- Keywords
- guedel airway, airway management, difficult bag mask ventilation, tulip airway
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Tulip AirwayDevice
In this study, patients scheduled for surgery under general anesthesia who meet the criteria for anticipated difficult mask ventilation will be included. Randomization will be performed to determine which device will be used first. If the Tulip airway is selected as the first device in the randomization process, mask ventilation will be initiated with the Tulip airway.
Guedel AirwayDevice
In this study, patients scheduled for surgery under general anesthesia who meet the criteria for anticipated difficult mask ventilation will be included. Randomization will be performed to determine which device will be used first. If the Guedel airway is selected as the first device in the randomization process, mask ventilation will be initiated with the Guedel airway.
| Study group | Role | What they receive |
|---|---|---|
| Guedel Group | Active comparator | Guedel airway will be the first device during mask ventilation Receives: Device: Guedel Airway |
| Tulip Group | Experimental | Tulip airway wil be the initial device for mask ventilation Receives: Device: Tulip Airway |
What is being measured
The primary outcome is the main question the study is designed to answer.
Expiratory Tidal Volume
Patients in Group G will have a Guedel airway placed in a size appropriate for their weight, and the practitioner will hold the mask with both hands. Patients in Group T will have a Tulip airway placed in a size appropriate for their weight. In both groups, to prevent variability on the part of the practitioner, patients will be ventilated in pressure-controlled mode at 15 (centimeters of water) cmH₂O pressure, respiratory rate 10 breaths/min, an I:E ratio of 1:3, and an oxygen flow rate of 10 L/min without Positive End Expiratory Pressure (PEEP). For both groups, successful mask ventilation will be defined as a tidal volume (TV) of at least 250 ml.
Measured: Minute 5
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Oct 2025
- Study start1 Oct 2025
- Primary completion31 Aug 2026 (estimated)
- Study completion31 Aug 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (6)Papers the sponsor has linked to this study.
- Other trials for Difficult Mask VentilationStudies 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Ayse Zeynep Turan Civraz
- Sponsor type
- Other government
- Responsible party
- Sponsor-investigator, Ayse Zeynep Turan Civraz, Kocaeli City Hospital
- Investigators
- Ayşe Z Turan Cıvraz, Assoc. Prof., Principal investigator, Kocaeli City Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07204223
- Sponsor's protocol ID
- KSH- AZTC- 02
- Acronym
- TADMV
- Status last verified
- Aug 2026
- First submitted
- 11 Sep 2025
- Last updated
- 7 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data (IPD) underlying the findings of this study will be available upon reasonable request from qualified researchers, after de-identification, beginning 6 months following publication and ending 5 years later. Data will be shared for academic purposes with appropriate ethical approval and a signed data access agreement."
Publications
Shaikh A, Robinson PN, Hasan M. The Tulip GT(R) airway versus the facemask and Guedel airway: a randomised, controlled, cross-over study by Basic Life Support-trained airway providers in anaesthetised patients. Anaesthesia. 2016 Mar;71(3):315-9. doi: 10.1111/anae.13328. Epub 2015 Dec 19.
PubMed 26684684Imashuku Y, Kitagawa H, Mizuno T. Usefulness of Tulip Airway in Edentulous Elderly Patients. Anesth Prog. 2022 Sep 1;69(3):9-12. doi: 10.2344/anpr-69-01-01.
PubMed 36223186Koga K, Sata T, Kaku M, Takamoto K, Shigematsu A. Comparison of no airway device, the Guedel-type airway and the Cuffed Oropharyngeal Airway with mask ventilation during manual in-line stabilization. J Clin Anesth. 2001 Feb;13(1):6-10. doi: 10.1016/s0952-8180(00)00228-2.
PubMed 11259887Apfelbaum JL, Hagberg CA, Caplan RA, Blitt CD, Connis RT, Nickinovich DG, Hagberg CA, Caplan RA, Benumof JL, Berry FA, Blitt CD, Bode RH, Cheney FW, Connis RT, Guidry OF, Nickinovich DG, Ovassapian A; American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Practice guidelines for management of the difficult airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology. 2013 Feb;118(2):251-70. doi: 10.1097/ALN.0b013e31827773b2. No abstract available.
PubMed 23364566Bradley P, Chapman G, Crooke B, Greenland K. Airway Assessment.
Bucher JT, Vashisht R, Cooper JS. Bag-Valve-Mask Ventilation. 2025 May 3. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. Available from http://www.ncbi.nlm.nih.gov/books/NBK441924/
PubMed 28722953
Study at a glance
From the registry record, last updated by the sponsor on 7 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of the Tulip Airway and the Guedel Airway in Anticipated Difficult Mask Ventilation: A Prospective, Randomized, Controlled Crossover Trial
- ClinicalTrials.gov ID
- NCT07204223
- Acronym / sponsor ID
- TADMV / KSH- AZTC- 02
- Conditions
- Difficult Mask Ventilation, Airway Devices
- Keywords
- guedel airway, airway management, difficult bag mask ventilation, tulip airway
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- Ayse Zeynep Turan CivrazOther government
- Study start
- 1 Oct 2025 (actual)
- Primary completion
- 31 Aug 2026 (estimated)
- Study completion
- 31 Aug 2026 (estimated)
- First posted
- 2 Oct 2025 (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.
During surgery, right after anesthesia is given, the first step to help the patient breathe is to provide breathing support with a mask. This step is very important because if there is a problem with mask ventilation, the anesthesia team must quickly use other methods to help the patient breathe.
For some people, mask ventilation can be more difficult. Factors such as older age, having a beard, missing teeth, being overweight, sleep apnea, or certain facial shapes can make this process harder.
To make mask ventilation easier, special devices placed in the mouth are used. The most common one is called the Guedel airway. In recent years, a new device called the Tulip airway has also been introduced. The shape and features of the Tulip airway are designed to make breathing support easier.
In this study, we will compare the Tulip airway and the Guedel airway in patients who are expected to have more difficult mask ventilation. Our goal is to find out which device makes it easier and safer to help patients breathe.
Detailed description
The first step in airway management following anesthesia induction is the period of bag-mask ventilation. This step is the most critical phase of airway management because, if mask ventilation fails, the anesthesiologist must make a life-saving decision for the patient. Bag-mask ventilation is a technical skill acquired over time; therefore, difficulty in mask ventilation may be related to either the provider or the patient. According to the literature, the incidence of difficult mask ventilation varies between 0.08% and 15% in different studies.
The American Society of Anesthesiologists (ASA) defines difficult mask ventilation as inadequate mask or supraglottic airway (SGA) ventilation, excessive air leakage, or excessive resistance to airflow during inspiration or expiration. Signs of inadequate ventilation include, but are not limited to, absent or insufficient chest movement, absent or diminished breath sounds, auscultatory signs of severe obstruction, cyanosis, gastric insufflation or distension, decreased or inadequate oxygen saturation (SpO₂), absence or inadequacy of end-tidal carbon dioxide (EtCO₂), absence or inadequacy of expiratory gas flow on spirometry, and hemodynamic changes associated with hypoxemia or hypercarbia (e.g., hypertension, tachycardia, arrhythmia).
Predictors of difficult mask ventilation include age over 55 years, the presence of a beard, poor mask fit due to secretions, edentulism, a history of snoring or obstructive sleep apnea syndrome (OSAS), and obesity. In anesthesia practice, when faced with difficult mask ventilation, various maneuvers, two-hand techniques, and adjunct airway devices are employed. Among these devices are various oral airways, the most common of which is the Guedel airway.
In recent years, new oral airway devices have been introduced as alternatives to the Guedel airway. The Tulip airway is a novel oral airway that is longer than the Guedel airway, equipped with a cuff, and features a connector that allows attachment to the breathing circuit. These characteristics enable it to be secured within the oral cavity via its cuff, and connection to the breathing circuit allows for airway management that may be more comfortable for the anesthesiologist compared to two-handed mask control.
The superiority of the Tulip airway over the Guedel airway has been demonstrated in patients with cervical spine injury, in edentulous manikins, and in patients undergoing general anesthesia. However, it has not been studied in patients with anticipated difficult mask ventilation. The aim of our study is to investigate whether the Tulip airway provides superior performance to the classical Guedel airway during the mask ventilation phase in patients with anticipated difficult mask ventilation. We hypothesize that the use of the Tulip airway in such patients will improve respiratory parameters and reduce the risk of complications during mask ventilation.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Guedel Group | Active comparator | Device: Guedel AirwayGuedel airway will be the first device during mask ventilation |
| Tulip Group | Experimental | Device: Tulip AirwayTulip airway wil be the initial device for mask ventilation |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (12 listed)
- Patients aged between 18 and 75 years
- Patients scheduled for elective surgery under general anesthesia
- Patients with at least two risk factors for difficult mask ventilation, including:
- Age over 55 years
- Presence of beard
Key exclusion criteria (8 listed)
- Pregnant or breastfeeding women
- Patients with a history of airway surgery (e.g., tracheostomy, maxillofacial surgery)
- Patients with severe cardiopulmonary diseases (e.g., advanced Chronic obstructive Pulmonary Disease (COPD), pulmonary hypertension, severe heart failure)
- Patients with craniofacial anomalies or significant anatomical airway deformities
- Patients requiring emergency surgery
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 |
|---|---|---|
| Tulip AirwayIn this study, patients scheduled for surgery under general anesthesia who meet the criteria for anticipated difficult mask ventilation will be included. Randomization will be performed to determine which device will be used first. If the Tulip airway is selected as the first device in the randomization process, mask ventilation will be initiated with the Tulip airway. | Device | Tulip Group |
| Guedel AirwayIn this study, patients scheduled for surgery under general anesthesia who meet the criteria for anticipated difficult mask ventilation will be included. Randomization will be performed to determine which device will be used first. If the Guedel airway is selected as the first device in the randomization process, mask ventilation will be initiated with the Guedel airway. | Device | Guedel Group |
Primary outcome
Expiratory Tidal Volume
Time frame: Minute 5
Patients in Group G will have a Guedel airway placed in a size appropriate for their weight, and the practitioner will hold the mask with both hands. Patients in Group T will have a Tulip airway placed in a size appropriate for their weight. In both groups, to prevent variability on the part of the practitioner, patients will be ventilated in pressure-controlled mode at 15 (centimeters of water) cmH₂O pressure, respiratory rate 10 breaths/min, an I:E ratio of 1:3, and an oxygen flow rate of 10 L/min without Positive End Expiratory Pressure (PEEP). For both groups, successful mask ventilation will be defined as a tidal volume (TV) of at least 250 ml.
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 7 Aug 2026.
- Background: PubMed 26684684Shaikh A, Robinson PN, Hasan M. The Tulip GT(R) airway versus the facemask and Guedel airway: a randomised, controlled, cross-over study by Basic Life Support-trained airway providers in anaesthetised patients. Anaesthesia. 2016 Mar;71(3):315-9. doi: 10.1111/anae.13328. Epub 2015 Dec 19.
- Background: PubMed 36223186Imashuku Y, Kitagawa H, Mizuno T. Usefulness of Tulip Airway in Edentulous Elderly Patients. Anesth Prog. 2022 Sep 1;69(3):9-12. doi: 10.2344/anpr-69-01-01.
- Background: PubMed 11259887Koga K, Sata T, Kaku M, Takamoto K, Shigematsu A. Comparison of no airway device, the Guedel-type airway and the Cuffed Oropharyngeal Airway with mask ventilation during manual in-line stabilization. J Clin Anesth. 2001 Feb;13(1):6-10. doi: 10.1016/s0952-8180(00)00228-2.
- Background: PubMed 23364566Apfelbaum JL, Hagberg CA, Caplan RA, Blitt CD, Connis RT, Nickinovich DG, Hagberg CA, Caplan RA, Benumof JL, Berry FA, Blitt CD, Bode RH, Cheney FW, Connis RT, Guidry OF, Nickinovich DG, Ovassapian A; American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Practice guidelines for management of the difficult airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology. 2013 Feb;118(2):251-70. doi: 10.1097/ALN.0b013e31827773b2. No abstract available.
- BackgroundBradley P, Chapman G, Crooke B, Greenland K. Airway Assessment.
- Background: PubMed 28722953Bucher JT, Vashisht R, Cooper JS. Bag-Valve-Mask Ventilation. 2025 May 3. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. Available from http://www.ncbi.nlm.nih.gov/books/NBK441924/
- Individual participant dataSharing planned: No. Individual participant data (IPD) underlying the findings of this study will be available upon reasonable request from qualified researchers, after de-identification, beginning 6 months following publication and ending 5 years later. Data will be shared for academic purposes with appropriate ethical approval and a signed data access agreement."
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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.
Bedirhan Günel, MD contact
Ayşe Z Turan Cıvraz, Assoc. Prof. principal investigator
Kocaeli City Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Tulip Airway and Guedel Airway in people with Difficult Mask Ventilation and Airway Devices, run by Ayse Zeynep Turan Civraz 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 12 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 7 Aug 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?
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 Ayşe Z Turan Cıvraz, Assoc. Prof. (+905054695850, ayse.zeynep@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Expiratory Tidal Volume (time frame: Minute 5). 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 NCT07204223, which also lists 6 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 7 Aug 2026.