ObesityNCT06305273
Effectiveness of Two Different Body Positions During Facemask Ventilation in Obese Patients
A study testing Head position for face mask ventilation during induction supine and Head position for face mask ventilation during induction head elevated in people with Obesity, run by Mount Sinai Hospital, Canada at 1 site in Canada.
Trial summary
It is important to provide enough oxygen to the patients who are asleep during surgery. One way to do this is by using a mask placed over the face to help them breathe. When it becomes difficult getting enough oxygen into the patient's body using the mask, it's called difficult mask ventilation. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Obesity
- What is being tested?
- Head position for face mask ventilation during induction supine and Head position for face mask ventilation during induction head elevated
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 50 participants
- Where
- 1 siteCanada
- Study dates
- 25 Mar 2024to 1 Dec 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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- BMI > 40 kg/m2
- age > 18 years
- scheduled for elective surgery under general anesthesia
- have the ability to comprehend the rationale for the study and provide consent
Who cannot join
- pregnancy,
- risk of aspiration of gastric content
- patients using glucagon-like peptide(GLP)-1 agonists
- emergency cases
- upper airway disease or airway anatomical abnormalities
- presence of major cardiovascular, respiratory, or cerebral vascular disease
- if the provider anesthesiologist indicates an awake technique to secure the airway
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site, 1 recruiting
- Recruiting
Mount Sinai Hospital
Toronto, Ontario, M5G 1X5
Dr. Fabricio B Zasso, MD, MHSc, MBA, 416-586-5270, Fabricio.Zasso@sinaihealth.ca
About this study
Official title: Effectiveness of Two Different Body Positions During Facemask Ventilation in Class 3 Obesity Patients: a Randomized Crossover Trial
It is important to provide enough oxygen to the patients who are asleep during surgery. One way to do this is by using a mask placed over the face to help them breathe. When it becomes difficult getting enough oxygen into the patient's body using the mask, it's called difficult mask ventilation. There can be different reasons for this, and having a higher BMI is one of them. Body physique is assessed by Body Mass Index (BMI). This calculation gives an indication of a person's weight relative to their height.
There is some evidence in the research literature to suggest that when the patient is positioned in a way that helps their airway, like using a device to lift their head and torso 25 degrees , it might help the process of getting enough oxygen work better. The study aims to determine if patients with high BMI can breathe better using a face mask while they are in a head elevated position compared to lying flat on their back.
Read the detailed description
Facemask ventilation is an important technique applied by anesthesiologists after induction of general anesthesia and before tracheal intubation. It is also used as a rescue maneuver in situations where a patient's consciousness is compromised affecting oxygenation. Obesity is well known to be one of the difficult predictors for facemask ventilation. In fact, the occurrence of difficult facemask ventilation is more frequent in obese patients than non obese. One of the maneuvers described to optimize the effectiveness of facemask ventilation in the general population is positioning the patient in a 25 degree head elevated position. A previous study has demonstrated improvement in facemask ventilation in obese patients with BMI from 30 to 40 kg/m2 in the head elevated position, compared to supine. However, it is not yet determined if this is applicable to patients with a BMI above 40 kg/m2. Adult obese patients with BMI of at least 40 kg/m2 will be randomized to be ventilated after induction of general anesthesia via a face mask while in one of the positions: supine or head elevated, while the volume of air that enters and exits the lungs is measured. Participants will then be changed to the second position, ventilated in the same manner and measures obtained again.
Do patients with class 3 obesity positioned in the head elevated position can be better ventilated with a face mask and positive pressure, compared to the supine position?
- Conditions
- Obesity
- Being tested
- Head position for face mask ventilation during induction supine, Head position for face mask ventilation during induction head elevated
- Medical subject headings
- Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Head position for face mask ventilation during induction supineOther
Participant to be ventilated starting 2 minutes after induction of general anesthesia via a face mask while in supine position. Participants will be crossed over to the head elevated position after the first measurement is obtained.
Head position for face mask ventilation during induction head elevatedOther
Participant to be ventilated starting 2 minutes after induction of general anesthesia via a face mask while in head elevated position. Participants will be crossed over to the supine position after the first measurement is obtained.
| Study group | Role | What they receive |
|---|---|---|
| Supine | Experimental | Participant will be ventilated with facemask while in supine position. Receives: Other: Head position for face mask ventilation during induction supine |
| Head elevated | Experimental | Participant will be ventilated with facemask while in head elevated position. Receives: Other: Head position for face mask ventilation during induction head elevated |
What is being measured
The primary outcome is the main question the study is designed to answer.
Average tidal volume
The primary outcome for this trial is the average tidal volume in 10 ventilations in each position, flat or head elevated.
Measured: During induction.
Secondary outcomes (8)
Predictors for difficult mask ventilation like BMI
Secondary outcome will be: the incidence and correlation of other predictors for difficult mask ventilation like BMI.
Measured: During induction
Predictors for difficult mask ventilation like presence of beard
Secondary outcomes will be: the incidence and correlation of other predictors for difficult mask ventilation like, presence of a beard.
Measured: During induction
Predictors for difficult mask ventilation like Mallampati classification III or IV
Secondary outcomes will be: the incidence and correlation of other predictors for difficult mask ventilation like Mallampati classification III or IV.
Measured: During induction
Predictors for difficult mask ventilation like age of 57 yo or older.
Secondary outcomes will be: the incidence and correlation of other predictors for difficult mask ventilation like, age of 57 yo or older.
Measured: During induction
Predictors for difficult mask ventilation like severely limited mandibular protrusion
Secondary outcomes will be: the incidence and correlation of other predictors for difficult mask ventilation like severely limited mandibular protrusion.
Measured: During induction
Predictors for difficult mask ventilation like history of snoring.
Secondary outcomes will be: the incidence and correlation of other predictors for difficult mask ventilation like history of snoring.
Measured: During induction
Oropharyngeal airway
Incidence of use of an oropharyngeal airway during the protocol.
Measured: During induction
Insufficient mask ventilation
Incidence of insufficient mask ventilation (defined as tidal volume (Vt) < 4 ml/kg IBW), or failed facemask ventilation defined as absence of End-tidal carbon dioxide(EtCO2) after 3 consecutive ventilations.
Measured: During induction.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Mar 2024
- Study start25 Mar 2024
- Primary completion1 Dec 2026 (estimated)
- Study completion1 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ObesityStudies 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
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- This study is a prospective randomized cross-over trial to be conducted at Mount Sinai Hospital (Toronto, Ontario, Canada).
- Masking
- None (open label)
- Enrolment
- 50 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Mount Sinai Hospital, Canada
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Fabricio Zasso, MD, Principal investigator, MOUNT SINAI HOSPITAL
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06305273
- Sponsor's protocol ID
- 23-0150-A
- Status last verified
- Jun 2026
- First submitted
- 26 Feb 2024
- Last updated
- 17 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 17 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effectiveness of Two Different Body Positions During Facemask Ventilation in Class 3 Obesity Patients: a Randomized Crossover Trial
- ClinicalTrials.gov ID
- NCT06305273
- Acronym / sponsor ID
- 23-0150-A
- Conditions
- Obesity
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 50 participants (estimated)
- Lead sponsor
- Mount Sinai Hospital, CanadaUniversity, hospital or other
- Study start
- 25 Mar 2024 (actual)
- Primary completion
- 1 Dec 2026 (estimated)
- Study completion
- 1 Dec 2026 (estimated)
- First posted
- 12 Mar 2024 (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.
It is important to provide enough oxygen to the patients who are asleep during surgery. One way to do this is by using a mask placed over the face to help them breathe. When it becomes difficult getting enough oxygen into the patient's body using the mask, it's called difficult mask ventilation. There can be different reasons for this, and having a higher BMI is one of them. Body physique is assessed by Body Mass Index (BMI). This calculation gives an indication of a person's weight relative to their height.
There is some evidence in the research literature to suggest that when the patient is positioned in a way that helps their airway, like using a device to lift their head and torso 25 degrees , it might help the process of getting enough oxygen work better. The study aims to determine if patients with high BMI can breathe better using a face mask while they are in a head elevated position compared to lying flat on their back.
Detailed description
Facemask ventilation is an important technique applied by anesthesiologists after induction of general anesthesia and before tracheal intubation. It is also used as a rescue maneuver in situations where a patient's consciousness is compromised affecting oxygenation. Obesity is well known to be one of the difficult predictors for facemask ventilation. In fact, the occurrence of difficult facemask ventilation is more frequent in obese patients than non obese. One of the maneuvers described to optimize the effectiveness of facemask ventilation in the general population is positioning the patient in a 25 degree head elevated position. A previous study has demonstrated improvement in facemask ventilation in obese patients with BMI from 30 to 40 kg/m2 in the head elevated position, compared to supine. However, it is not yet determined if this is applicable to patients with a BMI above 40 kg/m2. Adult obese patients with BMI of at least 40 kg/m2 will be randomized to be ventilated after induction of general anesthesia via a face mask while in one of the positions: supine or head elevated, while the volume of air that enters and exits the lungs is measured. Participants will then be changed to the second position, ventilated in the same manner and measures obtained again.
Do patients with class 3 obesity positioned in the head elevated position can be better ventilated with a face mask and positive pressure, compared to the supine position?
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- This study is a prospective randomized cross-over trial to be conducted at Mount Sinai Hospital (Toronto, Ontario, Canada).
| Arm | Type | Receives |
|---|---|---|
| Supine | Experimental | Other: Head position for face mask ventilation during induction supineParticipant will be ventilated with facemask while in supine position. |
| Head elevated | Experimental | Other: Head position for face mask ventilation during induction head elevatedParticipant will be ventilated with facemask while in head elevated position. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- BMI > 40 kg/m2
- age > 18 years
- scheduled for elective surgery under general anesthesia
- have the ability to comprehend the rationale for the study and provide consent
Key exclusion criteria (7 listed)
- pregnancy,
- risk of aspiration of gastric content
- patients using glucagon-like peptide(GLP)-1 agonists
- emergency cases
- upper airway disease or airway anatomical abnormalities
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 |
|---|---|---|
| Head position for face mask ventilation during induction supineParticipant to be ventilated starting 2 minutes after induction of general anesthesia via a face mask while in supine position. Participants will be crossed over to the head elevated position after the first measurement is obtained. | Other | Supine |
| Head position for face mask ventilation during induction head elevatedParticipant to be ventilated starting 2 minutes after induction of general anesthesia via a face mask while in head elevated position. Participants will be crossed over to the supine position after the first measurement is obtained. | Other | Head elevated |
Primary outcome
Average tidal volume
Time frame: During induction.
The primary outcome for this trial is the average tidal volume in 10 ventilations in each position, flat or head elevated.
8 secondary outcomes
Predictors for difficult mask ventilation like BMI
Time frame: During induction
Predictors for difficult mask ventilation like presence of beard
Time frame: During induction
Predictors for difficult mask ventilation like Mallampati classification III or IV
Time frame: During induction
Predictors for difficult mask ventilation like age of 57 yo or older.
Time frame: During induction
Predictors for difficult mask ventilation like severely limited mandibular protrusion
Time frame: During induction
Predictors for difficult mask ventilation like history of snoring.
Time frame: During induction
Oropharyngeal airway
Time frame: During induction
Insufficient mask ventilation
Time frame: During induction.
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 17 Jun 2026.
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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.
Fabricio Zasso, MD principal investigator
MOUNT SINAI 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 Head position for face mask ventilation during induction supine and Head position for face mask ventilation during induction head elevated in people with Obesity, run by Mount Sinai Hospital, Canada at 1 site in Canada.
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 7 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 17 Jun 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 Canada. 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 Fabricio Zasso, MD (416-586-4800, Fabricio.Zasso@sinaihealth.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Average tidal volume (time frame: During induction.). 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 17 Jun 2026.