Obesity, AbdominalNCT06287632
CPAP in Patients With Severe Obesity After Anesthesia
A study testing Recruitment/ITP-CPAP (Intervention A), Standard CPAP (Intervention B) and Atmospheric Pressure in people with Obesity, Abdominal and Anesthesia Morbidity, run by Massachusetts General Hospital.
Trial summary
The goal of this study is to compare two continuous positive airway pressure (CPAP) settings on heart and lung function in patients with severe obesity after anesthesia. The main questions it aims to answer are: 1. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Obesity, Abdominal, Anesthesia Morbidity, Apnea, Obstructive Sleep
- What is being tested?
- Recruitment/ITP-CPAP (Intervention A), Standard CPAP (Intervention B) and Atmospheric Pressure
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 60 participants
- Where
- No sites listed yet
- Study dates
- Jun 2026to Jun 2027
- 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
- Adult patients (≥ 18 years old) scheduled for elective non-cardiothoracic surgery requiring general anesthesia with an endotracheal tube
- Planned admission to the post-anesthesia care unit (PACU) after surgery
- BMI ≥ 40 kg/m2
- At the time of baseline measurements in the PACU, patients meet the following criteria:
- Receiving ≤ 6 liters of supplemental nasal cannula oxygen
- Alert as defined by a Richmond Agitation Sedation Scale of 0 or -1
- Oriented to person, place, and time
Who cannot join
- Pregnancy, suspected pregnancy or less than six weeks postpartum Known or current pneumothorax
- Hemodynamic instability at the time of study assessment in the PACU defined as:
- systolic blood pressure <90 mmHg or >180 mmHg
- mean blood pressure <60 or >130 mmHg
- Any use of intravenous vasoactive agent
- heart rate < 50 or > 120 beats per minute
Show all 21Show fewer
- Respiratory insufficiency in PACU defined as:
- Respiratory rate > 30
- Oxygen saturation < 92%
- Receiving > 6 liters of supplemental oxygen
- Known chronic lung disease requiring supplemental oxygen at home
- Known systolic heart dysfunction (left ventricular ejection fraction ≤ 30%)
- Contraindication for esophageal catheter placement:
- Known esophageal varices
- Known bacterial sinusitis
- Recent esophageal, nasopharyngeal, or laryngeal trauma or surgery
- Known coagulopathy: including history of thrombocytopenia defined as platelet count <50,000; presence of hemophilia; known genetic disorder of coagulation (e.g.,deficits of protein C, protein S, von Willebrand factor) or oral and subcutaneous anticoagulation treatment (e.g., heparin, warfarin, and or other oral anticoagulants)
- Contraindication for electrical impedance tomograph belt placement:
- Pacemaker and/or internal cardiac defibrillator
- Chest skin injury
- Concern for study inclusion by the perioperative nurse or anesthesia team
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
Lorenzo Berra contact
About this study
Official title: Assessment of Cardiopulmonary Function in Response to Continuous Positive Airway Pressure in Patients With Severe Obesity After Anesthesia
The goal of this study is to compare two continuous positive airway pressure (CPAP) settings on heart and lung function in patients with severe obesity after anesthesia. The main questions it aims to answer are:
- Does a recruitment maneuver and CPAP set to intrathoracic pressure (ITP) improve cardiopulmonary function compared to standard CPAP settings in patients with severe obesity after anesthesia?
- Does the location of adipose tissue influence the response to CPAP settings in patients with severe obesity after anesthesia?
Read more
Participants will undergo monitoring of their intrathoracic pressure using an esophageal catheter. In the recovery area after anesthesia, participants will receive two CPAP settings, each for 20 minutes.
- Intervention 1: Recruitment maneuver and CPAP will set to the level of intrathoracic pressure
- Intervention 2: CPAP set to home settings (if OSA is present) or between 8-10 cmH20 (if OSA is not present).
Read the detailed description
The current proposed crossover study is a single center, open-label clinical trial in patients who have severe obesity (defined by body mass index greater than or equal to 40 kg/m2) and are recovering from anesthesia. The primary aim is to describe the difference cardiopulmonary function between two settings for continuous positive airway pressure (CPAP), using electrical impedance tomography (EIT), transthoracic echocardiography, and esophageal pressure monitoring to measure response. The secondary aim is to determine whether the location of adipose tissue modifies responses to CPAP settings.
The study protocol consists of placing an esophageal catheter to monitor intrathoracic pressure in the operating room when the participant is under anesthesia. In the post-anesthesia care unit, participants will receive two CPAP settings, in random order, for 20 minutes each. One setting is a recruitment maneuver and CPAP set to the level of end-expiratory pressure (intrathoracic pressure). Another setting is a CPAP set to home levels (if known) or 8-10 cmH20 if not on home CPAP. There will be a 10 minute washout period between interventions. Investigators will monitor airway and esophageal pressure, ventilation with electrical impedance tomography, right heart function with transthoracic echocardiography, and abdominal muscle contraction with ultrasound. Waist and hip circumference will be measured prior to CPAP.
- Conditions
- Obesity, Abdominal, Anesthesia Morbidity, Apnea, Obstructive Sleep, Atelectases, Postoperative Pulmonary, Ventilator Lung
- Being tested
- Recruitment/ITP-CPAP (Intervention A), Standard CPAP (Intervention B), Atmospheric Pressure
- Keywords
- clinical trial, crossover studies, continuous positive airway pressure, electrical impedance tomography, esophageal pressure monitoring, transthoracic echocardiography
- Medical subject headings
- Obesity, Abdominal, Sleep Apnea, Obstructive, Pulmonary Atelectasis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Recruitment/ITP-CPAP (Intervention A)Device
Participant will receive a recruitment maneuver followed by CPAP set to the level of end-expiratory esophageal pressure (measured during atmospheric pressure breathing). The intervention will last for 20 minutes.
Standard CPAP (Intervention B)Device
Participant will receive their home CPAP (if on CPAP at home) or CPAP at 8-10 cmH20 (if not on CPAP at home or no known diagnosis of OSA). The intervention will last for 20 minutes.
Atmospheric PressureDevice
Participant will breathe at atmosphere pressure (no CPAP) with supplemental oxygen as needed per clinical guidance.
| Study group | Role | What they receive |
|---|---|---|
| Recruitment and ITP-CPAP | Experimental | Recruitment maneuver followed by CPAP set to intrathoracic pressure (ITP) Receives: Device: Recruitment/ITP-CPAP (Intervention A) |
| Standard CPAP | Active comparator | CPAP set to home level of CPAP (if known) or CPAP set to standard levels (8-10 cmH20) Receives: Device: Standard CPAP (Intervention B) |
| Atmospheric pressure | Placebo comparator | Breathing without CPAP Receives: Device: Atmospheric Pressure |
What is being measured
The primary outcome is the main question the study is designed to answer.
End expiratory lung impedance
End expiratory lung impedance, a surrogate of end expiratory lung volume, measured from EIT
Measured: Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)
Secondary outcomes (8)
Regional lung ventilation
% of relative ventilation to ventral and dorsal lung regions, measured from EIT
Measured: Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)
Right ventricular function
Defined by tricuspid annular plane systolic excursion, measured from transthoracic echocardiogram
Measured: Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)
Mean pulmonary artery pressure
Defined by pulmonary artery acceleration time using transthoracic echocardiography
Measured: Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)
Inspiratory effort
delta esophageal pressure, calculated as the negative deflections of esophageal pressure from the onset of inspiration and Pressure time product, the time-based integral of the Pes tracing during inspiration, per breath and per minute, measured from esophageal pressure tracing
Measured: Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)
Abdominal muscle thickness
Thickness of the muscles involved in expiration, measured by ultrasound - lateral abdominal wall muscles (external oblique, internal oblique, and transversus abdominis muscles)
Measured: Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)
Respiratory rate
breath per minute
Measured: Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)
Oxygen saturation
Defined from pulse oximetry
Measured: Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)
Systemic blood pressure
Defined by non-invasive blood pressure measurement
Measured: Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Mar 2024
- Study startJun 2026 (estimated)
- Primary completionNov 2026 (estimated)
- Study completionJun 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Obesity, AbdominalStudies of the same condition, open and under way.
- More trials run by Massachusetts General HospitalThe sponsor's other registered studies.
- 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
- Masking
- None (open label)
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Massachusetts General Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Timothy G. Gaulton, MD, Massachusetts General Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06287632
- Sponsor's protocol ID
- 2024P000451
- Status last verified
- Nov 2025
- First submitted
- 16 Feb 2024
- Last updated
- 18 Nov 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: All data analysis codes developed for this project in MATLAB (for electrical impedance tomography) or R will be thoroughly documented and made openly accessible on GitHub. We will make de-identified data available via the vivli platform (http://vivli.org/), non-profit clinical research data sharing platform. All data will be shared publicly under a data use agreement through a managed access process.
Study at a glance
From the registry record, last updated by the sponsor on 18 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Assessment of Cardiopulmonary Function in Response to Continuous Positive Airway Pressure in Patients With Severe Obesity After Anesthesia
- ClinicalTrials.gov ID
- NCT06287632
- Acronym / sponsor ID
- 2024P000451
- Conditions
- Obesity, Abdominal, Anesthesia Morbidity, Apnea, Obstructive Sleep, Atelectases, Postoperative Pulmonary, Ventilator Lung
- Keywords
- clinical trial, crossover studies, continuous positive airway pressure, electrical impedance tomography, esophageal pressure monitoring, transthoracic echocardiography
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Massachusetts General HospitalUniversity, hospital or other
- Study start
- Jun 2026 (estimated)
- Primary completion
- Nov 2026 (estimated)
- Study completion
- Jun 2027 (estimated)
- First posted
- 1 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.
The goal of this study is to compare two continuous positive airway pressure (CPAP) settings on heart and lung function in patients with severe obesity after anesthesia. The main questions it aims to answer are:
- Does a recruitment maneuver and CPAP set to intrathoracic pressure (ITP) improve cardiopulmonary function compared to standard CPAP settings in patients with severe obesity after anesthesia?
- Does the location of adipose tissue influence the response to CPAP settings in patients with severe obesity after anesthesia?
Participants will undergo monitoring of their intrathoracic pressure using an esophageal catheter. In the recovery area after anesthesia, participants will receive two CPAP settings, each for 20 minutes.
- Intervention 1: Recruitment maneuver and CPAP will set to the level of intrathoracic pressure
- Intervention 2: CPAP set to home settings (if OSA is present) or between 8-10 cmH20 (if OSA is not present).
Detailed description
The current proposed crossover study is a single center, open-label clinical trial in patients who have severe obesity (defined by body mass index greater than or equal to 40 kg/m2) and are recovering from anesthesia. The primary aim is to describe the difference cardiopulmonary function between two settings for continuous positive airway pressure (CPAP), using electrical impedance tomography (EIT), transthoracic echocardiography, and esophageal pressure monitoring to measure response. The secondary aim is to determine whether the location of adipose tissue modifies responses to CPAP settings.
The study protocol consists of placing an esophageal catheter to monitor intrathoracic pressure in the operating room when the participant is under anesthesia. In the post-anesthesia care unit, participants will receive two CPAP settings, in random order, for 20 minutes each. One setting is a recruitment maneuver and CPAP set to the level of end-expiratory pressure (intrathoracic pressure). Another setting is a CPAP set to home levels (if known) or 8-10 cmH20 if not on home CPAP. There will be a 10 minute washout period between interventions. Investigators will monitor airway and esophageal pressure, ventilation with electrical impedance tomography, right heart function with transthoracic echocardiography, and abdominal muscle contraction with ultrasound. Waist and hip circumference will be measured prior to CPAP.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Recruitment and ITP-CPAP | Experimental | Device: Recruitment/ITP-CPAP (Intervention A)Recruitment maneuver followed by CPAP set to intrathoracic pressure (ITP) |
| Standard CPAP | Active comparator | Device: Standard CPAP (Intervention B)CPAP set to home level of CPAP (if known) or CPAP set to standard levels (8-10 cmH20) |
| Atmospheric pressure | Placebo comparator | Device: Atmospheric PressureBreathing without CPAP |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- Adult patients (≥ 18 years old) scheduled for elective non-cardiothoracic surgery requiring general anesthesia with an endotracheal tube
- Planned admission to the post-anesthesia care unit (PACU) after surgery
- BMI ≥ 40 kg/m2
- At the time of baseline measurements in the PACU, patients meet the following criteria:
Key exclusion criteria (21 listed)
- Pregnancy, suspected pregnancy or less than six weeks postpartum Known or current pneumothorax
- Hemodynamic instability at the time of study assessment in the PACU defined as:
- Respiratory insufficiency in PACU defined as:
- Known chronic lung disease requiring supplemental oxygen at home
- Known systolic heart dysfunction (left ventricular ejection fraction ≤ 30%)
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 |
|---|---|---|
| Recruitment/ITP-CPAP (Intervention A)Participant will receive a recruitment maneuver followed by CPAP set to the level of end-expiratory esophageal pressure (measured during atmospheric pressure breathing). The intervention will last for 20 minutes. | Device | Recruitment and ITP-CPAP |
| Standard CPAP (Intervention B)Participant will receive their home CPAP (if on CPAP at home) or CPAP at 8-10 cmH20 (if not on CPAP at home or no known diagnosis of OSA). The intervention will last for 20 minutes. | Device | Standard CPAP |
| Atmospheric PressureParticipant will breathe at atmosphere pressure (no CPAP) with supplemental oxygen as needed per clinical guidance. | Device | Atmospheric pressure |
Primary outcome
End expiratory lung impedance
Time frame: Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)
End expiratory lung impedance, a surrogate of end expiratory lung volume, measured from EIT
8 secondary outcomes
Regional lung ventilation
Time frame: Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)
Right ventricular function
Time frame: Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)
Mean pulmonary artery pressure
Time frame: Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)
Inspiratory effort
Time frame: Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)
Abdominal muscle thickness
Time frame: Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)
Respiratory rate
Time frame: Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)
Oxygen saturation
Time frame: Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)
Systemic blood pressure
Time frame: Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)
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 18 Nov 2025.
- Individual participant dataSharing planned: Yes. All data analysis codes developed for this project in MATLAB (for electrical impedance tomography) or R will be thoroughly documented and made openly accessible on GitHub. We will make de-identified data available via the vivli platform (http://vivli.org/), non-profit clinical research data sharing platform. All data will be shared publicly under a data use agreement through a managed access process.
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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.
Lorenzo Berra contact
Questions about this trial
What is this clinical trial studying?
A study testing Recruitment/ITP-CPAP (Intervention A), Standard CPAP (Intervention B) and Atmospheric Pressure in people with Obesity, Abdominal and Anesthesia Morbidity, run by Massachusetts General Hospital.
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 7 inclusion and 21 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: opening soon, as of the sponsor's last update on 18 Nov 2025. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. 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 Timothy Gaulton, MD, MSc (617-643-7733, tgaulton@mgh.harvard.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
End expiratory lung impedance (time frame: Assessed at baseline during atmospheric pressure breathing (no CPAP), assessed at the end of intervention A (20 minutes), assessed at end of intervention B (20 minutes)). 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 18 Nov 2025.