Gastric InsufflationNCT05979129
Gastric Insufflation During Facemask Ventilation at Different Levels of End-expiratory Pressure in Obese Patients
A study testing zero PEEP, low PEEP and high PEEP in people with Gastric Insufflation and Face-mask Ventilation, run by Kasr El Aini Hospital at 1 site in Egypt.
Trial summary
Gastric insufflation occurs when the inspiratory pressure exceeds the lower esophageal sphincter pressure. Thus, it is desirable to avoid excessive positive pressure during mask ventilation after induction of anesthesia and keeping the inspiratory pressure <15-20 cmH2O.In patients with obesity the lower compliance of… Read more about this study
- Who is it for?
- Ages 18 to 60 years
- Conditions the study is for
- Gastric Insufflation, Face-mask Ventilation, Obese
- What is being tested?
- zero PEEP, low PEEP and high PEEP
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 162 participants
- Where
- 1 siteEgypt
- Study dates
- 6 Aug 2023to 28 Apr 2024
- Phase
- Interventional
- 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 to 60 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- adult patients,
- with American Society of Anesthesiologists physical status II,
- body mass index >35 kg/m2,
- scheduled for elective surgery under general anesthesia.
Who cannot join
- Patients at increased risk of difficult mask ventilation: Mallampati classification >2, presence of beard, limited neck extension, limited jaw protrusion, patients with history of obstructive sleep apnea or STOP-Bang score>2
- Patients at risk of aspiration or history of esophageal reflux.
- Patients with craniofacial anomalies, and pregnant patients
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Comparing the Incidence of Gastric Insufflation During Facemask Ventilation at Different Levels of End-expiratory Pressure During Induction of Anesthesia in Obese Patients: a Randomized Controlled Study
Gastric insufflation occurs when the inspiratory pressure exceeds the lower esophageal sphincter pressure. Thus, it is desirable to avoid excessive positive pressure during mask ventilation after induction of anesthesia and keeping the inspiratory pressure <15-20 cmH2O.In patients with obesity the lower compliance of the respiratory system usually requires higher inspiratory pressures to maintain adequate ventilation making these patients more prone to gastric insufflation. This high risk of gastric insufflation can be aggravated by the use of positive end-expiratory pressure (PEEP) which is recommended to avoid lung atelectasis. The application of PEEP during mask ventilation increases the risk of gastric insufflation as it reduces the pressure threshold at which gastric insufflation occur The optimum ventilatory strategy during mask ventilation should achieve the balance between adequate lung ventilation and avoiding gastric insufflation. In obese patients, it is not clear whether the use of PEEP during mask ventilation would increase the risk of gastric insufflation or not.
We hypothesize that using zero end-expiratory pressure (ZEEP) or low PEEP during mask ventilation would reduce the risk of gastric insufflation in comparison to high PEEP.
Read the detailed description
Upon arrival to the operating room, routine monitors (electrocardiogram, pulse oximetry, and non-invasive blood pressure monitor) will be applied, intravenous line will be secured. End-tidal CO2 monitoring will be initiated after induction of general anesthesia and starting face-mask ventilation. All patients will be positioned in the ramped position (achieved by elevation of the head and shoulders till achieving alignment of sternal notch and external auditory meatus). Preoxygenation will be achieved by pressure support ventilation with 5 cmH2O and FiO2 of 0.8 without PEEP for three minutes. Induction of anesthesia will be achieved using fentanyl (2 mcg/Kg lean body weight), propofol (2 mg/Kg lean body weight), and rocuronium (0.6 mg/Kg ideal body weight). After loss of verbal response, mask ventilation will be achieved by appropriate size face mask and oropharyngeal airway with 100% oxygen and double hand jaw thrust head tilt maneuver. The included patients will be receiving volume-controlled ventilation adjusted to deliver tidal volume of 8-10 mL/kg (ideal body weight), at I:E ratio of 1:2, inspiratory pause of 0.5 s, respiratory rate of 12 breath per minute, FiO2 of 0.8.
The 3 study groups will receive the planned ventilatory strategy for 120 seconds.
Assessment gastric insufflation during mask ventilation will be achieved by ultrasound assessment of gastric antrum (at the sagittal plane between left lobe of the liver and pancreas at level of the aorta). Gastric antral cross-sectional area (CSA) [ (longitudinal diameter) X (anteroposterior diameter) X π /4] will be assessed in between contractions before face mask ventilation and after insertion of endotracheal tube. [9] The proportion of change in the CSA will be calculated as (delta CSA %= [CSA after intubation - baseline CSA] / baseline CSA X 100). Significant gastric insufflation will be identified if the CSA increased by > 30% after endotracheal intubation in relation to the baseline.
Intermittent gastric auscultation will be performed during mask ventilation at 30, 60, 90, 120 seconds by a blinded investigator (the presence of gastric insufflation will be defined as a gurgling sound).
- Being tested
- zero PEEP, low PEEP, high PEEP
- Medical subject headings
- Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
zero PEEPOther
zero end-expiratory pressure during face mask ventilation
low PEEPOther
4 cmH2O PEEP during mask ventilation
high PEEPOther
8 cmH2O PEEP during mask ventilation
| Study group | Role | What they receive |
|---|---|---|
| ZEEP group | Active comparator | Not described Receives: Other: zero PEEP |
| Low PEEP | Active comparator | Not described Receives: Other: low PEEP |
| High PEEP | Active comparator | Not described Receives: Other: high PEEP |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in gastric cross sectional area more than 30%
number of patients with increase in percentage of change in gastric cross sectional area by more than 30%
Measured: 1 minute before preoxygenation and 1 minute after intubation
Secondary outcomes (6)
gastric cross sectional area
gastric cross sectional area measured by ultrasonography in cm2
Measured: 1 minute before preoxygenation and 1 minute after intubation
percentage of change in gastric cross sectional area
gastric cross sectional area after intubation divided by gastric cross sectional area before preoxygenation %
Measured: 1 minute before preoxygenation and 1 minute after intubation
tidal volume
mL/kg
Measured: 30 seconds until 120 seconds after induction of anesthesia
end-tidal CO2
mmHg
Measured: 30 seconds until 120 seconds after induction of anesthesia
Peak airway pressure
mmHg
Measured: 30 seconds until 120 seconds after induction of anesthesia
Gastric insufflation
incidence of gastric insufflation by auscultation
Measured: 30 seconds until 120 seconds after induction of anesthesia
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Aug 2023
- Study start6 Aug 2023
- Primary completion28 Apr 2024
- Study completion28 Apr 2024
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 Gastric InsufflationStudies 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
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 162 participants (actual)
Sponsor and investigators
- Lead sponsor
- Kasr El Aini Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Maha Mostafa Ahmad, MD, Kasr El Aini Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05979129
- Sponsor's protocol ID
- MD-65-2022
- Status last verified
- Aug 2024
- First submitted
- 30 Jul 2023
- Last updated
- 5 Aug 2024
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: data from this study will be available from PI upon reasonable request
Publications
Mostafa M, Hasanin A, Zakaria MM, Kandel H, Hamimy W, Abougabal A, Elshal MM. Comparing the effect of three levels of end-expiratory pressure during facemask ventilation on gastric insufflation in patients with obesity: a randomized controlled trial. J Anesth. 2025 Dec;39(6):887-895. doi: 10.1007/s00540-025-03531-9. Epub 2025 Jun 30.
PubMed 40586940
Study at a glance
From the registry record, last updated by the sponsor on 5 Aug 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparing the Incidence of Gastric Insufflation During Facemask Ventilation at Different Levels of End-expiratory Pressure During Induction of Anesthesia in Obese Patients: a Randomized Controlled Study
- ClinicalTrials.gov ID
- NCT05979129
- Acronym / sponsor ID
- MD-65-2022
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 162 participants (actual)
- Lead sponsor
- Kasr El Aini HospitalUniversity, hospital or other
- Study start
- 6 Aug 2023 (actual)
- Primary completion
- 28 Apr 2024 (actual)
- Study completion
- 28 Apr 2024 (actual)
- First posted
- 7 Aug 2023 (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.
Gastric insufflation occurs when the inspiratory pressure exceeds the lower esophageal sphincter pressure. Thus, it is desirable to avoid excessive positive pressure during mask ventilation after induction of anesthesia and keeping the inspiratory pressure <15-20 cmH2O.In patients with obesity the lower compliance of the respiratory system usually requires higher inspiratory pressures to maintain adequate ventilation making these patients more prone to gastric insufflation. This high risk of gastric insufflation can be aggravated by the use of positive end-expiratory pressure (PEEP) which is recommended to avoid lung atelectasis. The application of PEEP during mask ventilation increases the risk of gastric insufflation as it reduces the pressure threshold at which gastric insufflation occur The optimum ventilatory strategy during mask ventilation should achieve the balance between adequate lung ventilation and avoiding gastric insufflation. In obese patients, it is not clear whether the use of PEEP during mask ventilation would increase the risk of gastric insufflation or not.
We hypothesize that using zero end-expiratory pressure (ZEEP) or low PEEP during mask ventilation would reduce the risk of gastric insufflation in comparison to high PEEP.
Detailed description
Upon arrival to the operating room, routine monitors (electrocardiogram, pulse oximetry, and non-invasive blood pressure monitor) will be applied, intravenous line will be secured. End-tidal CO2 monitoring will be initiated after induction of general anesthesia and starting face-mask ventilation. All patients will be positioned in the ramped position (achieved by elevation of the head and shoulders till achieving alignment of sternal notch and external auditory meatus). Preoxygenation will be achieved by pressure support ventilation with 5 cmH2O and FiO2 of 0.8 without PEEP for three minutes. Induction of anesthesia will be achieved using fentanyl (2 mcg/Kg lean body weight), propofol (2 mg/Kg lean body weight), and rocuronium (0.6 mg/Kg ideal body weight). After loss of verbal response, mask ventilation will be achieved by appropriate size face mask and oropharyngeal airway with 100% oxygen and double hand jaw thrust head tilt maneuver. The included patients will be receiving volume-controlled ventilation adjusted to deliver tidal volume of 8-10 mL/kg (ideal body weight), at I:E ratio of 1:2, inspiratory pause of 0.5 s, respiratory rate of 12 breath per minute, FiO2 of 0.8.
The 3 study groups will receive the planned ventilatory strategy for 120 seconds.
Assessment gastric insufflation during mask ventilation will be achieved by ultrasound assessment of gastric antrum (at the sagittal plane between left lobe of the liver and pancreas at level of the aorta). Gastric antral cross-sectional area (CSA) [ (longitudinal diameter) X (anteroposterior diameter) X π /4] will be assessed in between contractions before face mask ventilation and after insertion of endotracheal tube. [9] The proportion of change in the CSA will be calculated as (delta CSA %= [CSA after intubation - baseline CSA] / baseline CSA X 100). Significant gastric insufflation will be identified if the CSA increased by > 30% after endotracheal intubation in relation to the baseline.
Intermittent gastric auscultation will be performed during mask ventilation at 30, 60, 90, 120 seconds by a blinded investigator (the presence of gastric insufflation will be defined as a gurgling sound).
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| ZEEP group | Active comparator | Other: zero PEEP |
| Low PEEP | Active comparator | Other: low PEEP |
| High PEEP | Active comparator | Other: high PEEP |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- adult patients,
- with American Society of Anesthesiologists physical status II,
- body mass index >35 kg/m2,
- scheduled for elective surgery under general anesthesia.
Key exclusion criteria (3 listed)
- Patients at increased risk of difficult mask ventilation: Mallampati classification >2, presence of beard, limited neck extension, limited jaw protrusion, patients with history of obstructive sleep apnea or STOP-Bang score>2
- Patients at risk of aspiration or history of esophageal reflux.
- Patients with craniofacial anomalies, and pregnant patients
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 |
|---|---|---|
| zero PEEPzero end-expiratory pressure during face mask ventilation | Other | ZEEP group |
| low PEEP4 cmH2O PEEP during mask ventilation | Other | Low PEEP |
| high PEEP8 cmH2O PEEP during mask ventilation | Other | High PEEP |
Primary outcome
Change in gastric cross sectional area more than 30%
Time frame: 1 minute before preoxygenation and 1 minute after intubation
number of patients with increase in percentage of change in gastric cross sectional area by more than 30%
6 secondary outcomes
gastric cross sectional area
Time frame: 1 minute before preoxygenation and 1 minute after intubation
percentage of change in gastric cross sectional area
Time frame: 1 minute before preoxygenation and 1 minute after intubation
tidal volume
Time frame: 30 seconds until 120 seconds after induction of anesthesia
end-tidal CO2
Time frame: 30 seconds until 120 seconds after induction of anesthesia
Peak airway pressure
Time frame: 30 seconds until 120 seconds after induction of anesthesia
Gastric insufflation
Time frame: 30 seconds until 120 seconds after induction of anesthesia
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 5 Aug 2024.
- Derived from this study: PubMed 40586940Mostafa M, Hasanin A, Zakaria MM, Kandel H, Hamimy W, Abougabal A, Elshal MM. Comparing the effect of three levels of end-expiratory pressure during facemask ventilation on gastric insufflation in patients with obesity: a randomized controlled trial. J Anesth. 2025 Dec;39(6):887-895. doi: 10.1007/s00540-025-03531-9. Epub 2025 Jun 30.
- Individual participant dataSharing planned: No. data from this study will be available from PI upon reasonable request
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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.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing zero PEEP, low PEEP and high PEEP in people with Gastric Insufflation and Face-mask Ventilation, run by Kasr El Aini Hospital at 1 site in Egypt.
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 3 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 5 Aug 2024. 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 Egypt. 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?
Change in gastric cross sectional area more than 30% (time frame: 1 minute before preoxygenation and 1 minute after intubation). 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 NCT05979129, 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 5 Aug 2024.