Airway ManagementNCT07340255
The 90% Effective Ventilation Pressure (EP90) for Esophageal Insufflation Avoidance During Anesthesia Induction
A study testing Ultrasonic and inflation determination in people with Airway Management and Induction of Anesthesia, run by Affiliated Hospital of Jiaxing University at 1 site in China.
Trial summary
Exploring the 90% Effective Ventilation Pressure (EP90) for Esophageal Insufflation Avoidance During Anesthesia Induction: The aim is to determine the optimal ventilation pressure for esophageal insufflation avoidance during anesthesia induction and to explore its guiding significance for anesthesia management. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Airway Management, Induction of Anesthesia
- What is being tested?
- Ultrasonic and inflation determination
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteChina
- Study dates
- 29 Sep 2025to Feb 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 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age: 18-65 years, regardless of gender;
- ASA classification: I-III;
- Scheduled for elective general anesthesia surgery;
- BMI: 18.0-28.0 kg/m²;
- Preoperative fasting: Solid food >6 hours, liquid >2 hours;
- Less than two from five criteria predicting difficult mask ventilation as described by Langeron et al.(Prediction of difficult mask ventilation. Anesthesiology 2000; 92:1229-36);
- No severe underlying conditions such as heart, lung, liver, or kidney disease;
- Signed informed consent and ability to cooperate with the study protocol.
Who cannot join
- Pregnant or breastfeeding women;
- History of upper gastrointestinal diseases such as gastroesophageal reflux disease, peptic ulcers, or hiatal hernia;
- Recent (within 2 weeks) respiratory infections, chronic cough, similar symptoms, and other known or predictable respiratory system diseases;
- Need for emergency surgery or airway obstruction after anesthesia induction requiring urgent intubation;
- Inability to achieve adequate oxygenation during mask ventilation (e.g., SpO₂ < 92% for 30 seconds, unresponsive to treatment);
- History of contraindications or allergies to study medications;
Show all 9Show fewer
- Inability to understand the study content or refusal to cooperate;
- Oropharyngeal or facial pathology;
- with an indwelling gastric tube, and who had previously undergone gastric surgery.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site, 1 recruiting
- Recruiting
Affiliated Hospital of Jiaxing University
Jiaxing
Qinghe Zhou
About this study
Official title: The 90% Effective Ventilation Pressure (EP90) for Esophageal Insufflation Avoidance During Anesthesia Induction: A Bias-Coin Design With Up-and-Down Sequential Allocation Trial
Exploring the 90% Effective Ventilation Pressure (EP90) for Esophageal Insufflation Avoidance During Anesthesia Induction: The aim is to determine the optimal ventilation pressure for esophageal insufflation avoidance during anesthesia induction and to explore its guiding significance for anesthesia management. The goal is to provide a more precise and personalized ventilation pressure setting standard for clinical anesthesia, thereby enhancing the safety of the anesthesia induction phase.
Read the detailed description
Pulmonary aspiration of gastric contents has been identified as one of the leading causes of anesthesia-related mortality. Even in fasting patients or those without known aspiration risks, such complications can still occur. In fact, in patients with unprotected airways during apnea, the introduction of air into the lungs during ventilation may become a potential trigger for gastric content aspiration. The entry of air can increase gastric pressure, leading to the reflux of gastric contents into the esophagus, which may subsequently result in hemodynamic instability and pulmonary failure. Therefore, airway management during anesthesia induction is crucial, particularly in the precise control of ventilation pressure, as it directly impacts the safety of the patient during surgery.
Previous studies have used gastric insufflation as the primary endpoint for evaluating the safety of ventilation pressures, often assessing the appearance of gastric gas in the stomach during mask ventilation. However, gastric insufflation typically occurs only after gas has passed through the esophagus and cardia, entering the gastric cavity-this process is a "terminal event" triggered by higher pressures. The esophagus, being structurally weaker than the stomach, is less tolerant to pressure. When gas first enters the esophagus, the cardia is not fully open, and if ventilation pressure continues to rise, it is easy to cause esophageal insufflation, further leading to gastric insufflation and even gastric content reflux. Since esophageal insufflation occurs earlier and has a lower pressure threshold, it can serve as a more sensitive indicator, providing an early warning to anesthesiologists about potential airway management issues.
To address this issue, determining the optimal ventilation pressure to avoid esophageal insufflation is particularly important. the 90% effective ventilation pressure (EP90) refers to the ventilation pressure that can avoid esophageal insufflation in 90% of cases, providing anesthesiologists with a quantitative reference for ventilation pressures.
This study employed a Sequential Allocation with Biased Coin Design (SABCD) trial, utilizing precise statistical methods to explore the EP90 for avoiding esophageal insufflation during anesthesia induction. The goal was to determine the optimal ventilation pressure for preventing esophageal insufflation during anesthesia induction and to explore its implications for anesthesia management. The ultimate aim is to provide a more precise and personalized ventilation pressure setting standard for clinical anesthesia, thereby enhancing the safety of the anesthesia induction phase.
- Conditions
- Airway Management, Induction of Anesthesia
- Being tested
- Ultrasonic and inflation determination
- Keywords
- Esophageal Insufflation, Airway Management, Ventilation, Bias-coin Design
- Medical subject headings
- Respiratory Aspiration
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Ultrasonic and inflation determinationOther
Before induction, during ventilation, and after intubation, the anesthesiologist used a 7-14 MHz linear array probe for transverse (supraclavicular) positioning to monitor the left paratracheal esophageal region in real time. The main criterion for assessment was the absence of esophageal gas during ventilation, which was considered a positive response. If gas was detected entering the esophagus on ultrasound, it was recorded as a negative response.
Additionally, the anesthesiologist performed a preoperative ultrasound examination of the gastric antrum to record baseline gastric antrum parameters. After successful tracheal intubation, a follow-up ultrasound of the gastric antrum was conducted to obtain postoperative gastric antrum parameters.
| Study group | Role | What they receive |
|---|---|---|
| Ventilation Pressure | Experimental | Anesthesia machine settings: pressure control mode, inspiratory-to-expiratory ratio of 1:2, respiratory rate of 15 breaths/min, 100% oxygen, no PEEP applied. Mask ventilation duration was standardized to 120 seconds, followed by tracheal intubation. Receives: Other: Ultrasonic and inflation determination |
What is being measured
The primary outcome is the main question the study is designed to answer.
EP90
The 90% effective ventilation pressure (EP90) for avoiding esophageal inflation refers to the minimum effective airway pressure (measured in cmH₂O) at which 90% of patients do not experience esophageal inflation during pressure-controlled mask ventilation during anesthesia induction.
Measured: Perioperative
Secondary outcomes (9)
EP95
The 95% effective ventilation pressure (EP95) for avoiding esophageal inflation refers to the minimum effective airway pressure (measured in cmH₂O) at which 95% of patients do not experience esophageal inflation during pressure-controlled mask ventilation during anesthesia induction.
Measured: Periprocedural
EP98
The 98% effective ventilation pressure(EP98) for avoiding esophageal inflation refers to the minimum effective airway pressure (measured in cmH₂O) at which 98% of patients do not experience esophageal inflation during pressure-controlled mask ventilation during anesthesia induction.
Measured: Periprocedural
Ventilation-related respiratory parameters
pulse oxygen saturation (SpO₂) was recorded at multiple time points during mask ventilation and 30/60/90/120 seconds after tracheal intubation.
Measured: Periprocedural
Ventilation-related respiratory parameters
end-tidal carbon dioxide (EtCO₂) was recorded at multiple time points during mask ventilation and 30/60/90/120 seconds after tracheal intubation.
Measured: Periprocedural
Ventilation-related respiratory parameters
end-tidal oxygen concentration (EtO₂) was recorded at multiple time points during mask ventilation and 30/60/90/120 seconds after tracheal intubation.
Measured: Periprocedural
Ventilation-related respiratory parameters
minute leak volume was recorded at multiple time points during mask ventilation and 30/60/90/120 seconds after tracheal intubation.
Measured: Periprocedural
Ventilation-related respiratory parameters
peak airway pressure (Ppeak) was recorded at multiple time points during mask ventilation and 30/60/90/120 seconds after tracheal intubation.
Measured: Periprocedural
Ventilation-related respiratory parameters
tidal volume (Vt) was recorded at multiple time points during mask ventilation and 30/60/90/120 seconds after tracheal intubation.
Measured: Periprocedural
Incidence of complications Incidence of complications
Including gastric distension, signs of aspiration, failure rate of mask ventilation [such as pulse oxygen saturation (SpO₂) < 92% lasting for 30 seconds], intubation condition score (Cormack-Lehane classification), hypoxemia and other adverse events.
Measured: Periprocedural
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 start29 Sep 2025
- Primary completionFeb 2026 (estimated)
- Study completionFeb 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Airway ManagementStudies 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
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Sequential
- Masking
- None (open label)
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Affiliated Hospital of Jiaxing University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Qing-he Zhou, Affiliated Hospital of Jiaxing University
- Investigators
- Qinghe Zhou, Dr., Study chair, Affiliated Hospital of Jiaxing University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07340255
- Sponsor's protocol ID
- 2025-KY-396
- Status last verified
- Jan 2026
- First submitted
- 28 Sep 2025
- Last updated
- 14 Jan 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Langeron O, Masso E, Huraux C, Guggiari M, Bianchi A, Coriat P, Riou B. Prediction of difficult mask ventilation. Anesthesiology. 2000 May;92(5):1229-36. doi: 10.1097/00000542-200005000-00009.
PubMed 10781266
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
- The 90% Effective Ventilation Pressure (EP90) for Esophageal Insufflation Avoidance During Anesthesia Induction: A Bias-Coin Design With Up-and-Down Sequential Allocation Trial
- ClinicalTrials.gov ID
- NCT07340255
- Acronym / sponsor ID
- 2025-KY-396
- Conditions
- Airway Management, Induction of Anesthesia
- Keywords
- Esophageal Insufflation, Airway Management, Ventilation, Bias-coin Design
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Affiliated Hospital of Jiaxing UniversityUniversity, hospital or other
- Study start
- 29 Sep 2025 (actual)
- Primary completion
- Feb 2026 (estimated)
- Study completion
- Feb 2026 (estimated)
- 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.
Exploring the 90% Effective Ventilation Pressure (EP90) for Esophageal Insufflation Avoidance During Anesthesia Induction: The aim is to determine the optimal ventilation pressure for esophageal insufflation avoidance during anesthesia induction and to explore its guiding significance for anesthesia management. The goal is to provide a more precise and personalized ventilation pressure setting standard for clinical anesthesia, thereby enhancing the safety of the anesthesia induction phase.
Detailed description
Pulmonary aspiration of gastric contents has been identified as one of the leading causes of anesthesia-related mortality. Even in fasting patients or those without known aspiration risks, such complications can still occur. In fact, in patients with unprotected airways during apnea, the introduction of air into the lungs during ventilation may become a potential trigger for gastric content aspiration. The entry of air can increase gastric pressure, leading to the reflux of gastric contents into the esophagus, which may subsequently result in hemodynamic instability and pulmonary failure. Therefore, airway management during anesthesia induction is crucial, particularly in the precise control of ventilation pressure, as it directly impacts the safety of the patient during surgery.
Previous studies have used gastric insufflation as the primary endpoint for evaluating the safety of ventilation pressures, often assessing the appearance of gastric gas in the stomach during mask ventilation. However, gastric insufflation typically occurs only after gas has passed through the esophagus and cardia, entering the gastric cavity-this process is a "terminal event" triggered by higher pressures. The esophagus, being structurally weaker than the stomach, is less tolerant to pressure. When gas first enters the esophagus, the cardia is not fully open, and if ventilation pressure continues to rise, it is easy to cause esophageal insufflation, further leading to gastric insufflation and even gastric content reflux. Since esophageal insufflation occurs earlier and has a lower pressure threshold, it can serve as a more sensitive indicator, providing an early warning to anesthesiologists about potential airway management issues.
To address this issue, determining the optimal ventilation pressure to avoid esophageal insufflation is particularly important. the 90% effective ventilation pressure (EP90) refers to the ventilation pressure that can avoid esophageal insufflation in 90% of cases, providing anesthesiologists with a quantitative reference for ventilation pressures.
This study employed a Sequential Allocation with Biased Coin Design (SABCD) trial, utilizing precise statistical methods to explore the EP90 for avoiding esophageal insufflation during anesthesia induction. The goal was to determine the optimal ventilation pressure for preventing esophageal insufflation during anesthesia induction and to explore its implications for anesthesia management. The ultimate aim is to provide a more precise and personalized ventilation pressure setting standard for clinical anesthesia, thereby enhancing the safety of the anesthesia induction phase.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Ventilation Pressure | Experimental | Other: Ultrasonic and inflation determinationAnesthesia machine settings: pressure control mode, inspiratory-to-expiratory ratio of 1:2, respiratory rate of 15 breaths/min, 100% oxygen, no PEEP applied. Mask ventilation duration was standardized to 120 seconds, followed by tracheal intubation. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (8 listed)
- Age: 18-65 years, regardless of gender;
- ASA classification: I-III;
- Scheduled for elective general anesthesia surgery;
- BMI: 18.0-28.0 kg/m²;
- Preoperative fasting: Solid food >6 hours, liquid >2 hours;
Key exclusion criteria (9 listed)
- Pregnant or breastfeeding women;
- History of upper gastrointestinal diseases such as gastroesophageal reflux disease, peptic ulcers, or hiatal hernia;
- Recent (within 2 weeks) respiratory infections, chronic cough, similar symptoms, and other known or predictable respiratory system diseases;
- Need for emergency surgery or airway obstruction after anesthesia induction requiring urgent intubation;
- Inability to achieve adequate oxygenation during mask ventilation (e.g., SpO₂ < 92% for 30 seconds, unresponsive to treatment);
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 |
|---|---|---|
| Ultrasonic and inflation determinationBefore induction, during ventilation, and after intubation, the anesthesiologist used a 7-14 MHz linear array probe for transverse (supraclavicular) positioning to monitor the left paratracheal esophageal region in real time. The main criterion for assessment was the absence of esophageal gas during ventilation, which was considered a positive response. If gas was detected entering the esophagus on ultrasound, it was recorded as a negative response. Additionally, the anesthesiologist performed a preoperative ultrasound examination of the gastric antrum to record baseline gastric antrum parameters. After successful tracheal intubation, a follow-up ultrasound of the gastric antrum was conducted to obtain postoperative gastric antrum parameters. | Other | Ventilation Pressure |
Primary outcome
EP90
Time frame: Perioperative
The 90% effective ventilation pressure (EP90) for avoiding esophageal inflation refers to the minimum effective airway pressure (measured in cmH₂O) at which 90% of patients do not experience esophageal inflation during pressure-controlled mask ventilation during anesthesia induction.
9 secondary outcomes
EP95
Time frame: Periprocedural
EP98
Time frame: Periprocedural
Ventilation-related respiratory parameters
Time frame: Periprocedural
Ventilation-related respiratory parameters
Time frame: Periprocedural
Ventilation-related respiratory parameters
Time frame: Periprocedural
Ventilation-related respiratory parameters
Time frame: Periprocedural
Ventilation-related respiratory parameters
Time frame: Periprocedural
Ventilation-related respiratory parameters
Time frame: Periprocedural
Incidence of complications Incidence of complications
Time frame: Periprocedural
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 14 Jan 2026.
- Results publication: PubMed 10781266Langeron O, Masso E, Huraux C, Guggiari M, Bianchi A, Coriat P, Riou B. Prediction of difficult mask ventilation. Anesthesiology. 2000 May;92(5):1229-36. doi: 10.1097/00000542-200005000-00009.
- 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.
Qinghe Zhou, Dr. study chair
Affiliated Hospital of Jiaxing University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Ultrasonic and inflation determination in people with Airway Management and Induction of Anesthesia, run by Affiliated Hospital of Jiaxing University at 1 site in China.
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 8 inclusion and 9 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 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 China. 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 Qinghe Zhou (13732573379, zqh10980@zjxu.edu.edu.cn), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
EP90 (time frame: Perioperative). 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 NCT07340255, which also lists 1 linked publication.
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.