ObesityNCT02492113

Effects of Different PEEP Levels on Work of Breathing in Morbidly Obese Patients Prior to and After Extubation

A study testing Positive end-expiratory pressure (PEEP) and ZEEP in people with Obesity, run by Massachusetts General Hospital at 1 site in United States.

Withdrawn

Withdrawn. The study stopped before anyone enrolled.

Official record

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Trial summary

The main purpose of this study is to define at the bedside the "Titrated-PEEP" level for obese patients that increases the likelihood of extubation and ventilator liberation. The investigators hypothesized that a titrated level of PEEP ("Titrated-PEEP") during SBT will keep the lung recruited, maintain oxygenation… Read more about this study

Who is it for?: Ages 18 years and older
Conditions the study is for: Obesity
What is being tested?: Positive end-expiratory pressure (PEEP) and ZEEP
Type of treatment: Surgery or procedure
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 0 participants
Where: 1 siteUnited States
Study dates: Nov 2015to 24 Nov 2025
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 years and older
All sexes
No healthy volunteers
Adult, Older adult

Who may be able to join

Intubated and mechanically ventilated;
Weaning from mechanical ventilation;
BMI ≥ 35 kg/m2 with waist circumference > 88 cm for women; waist circumference > 102 cm for men.
A well functioning arterial line.

Who cannot join

Known presence of esophageal varices
Recent esophageal trauma or surgery
Severe thrombocytopenia (PTL ≤ 5,000/mm3)
Severe coagulopathy (INR ≥ 4)
Presence of pneumothorax
Pregnancy
Pacemaker and/or internal cardiac defibrillator

Trial locations and contacts

1 site in 1 country.

United States1 site

Massachussets General Hospital
Boston, Massachusetts, 02114

Other trials in United States

About this study

The main purpose of this study is to define at the bedside the "Titrated-PEEP" level for obese patients that increases the likelihood of extubation and ventilator liberation.

The investigators hypothesized that a titrated level of PEEP ("Titrated-PEEP") during SBT will keep the lung recruited, maintain oxygenation, and decrease the work of breathing resulting in successful ventilator liberation. In addition, post-extubation the investigators hypothesize that these patients will require noninvasive ventilatory support in the form of CPAP at the level of "titrated-PEEP" used during the SBT.

Read the detailed description

The high WOB of morbidly obese patients is associated with respiratory muscle fatigue and failure in extubation. The investigators hypothesized that the use of a titrated PEEP level prior to and after extubation might improve successful extubation rates and avoid re-intubation.

In this study, patients will be awake and ventilated in the pressure support ventilation (PSV) mode. The investigators will apply different PEEP levels to measure WOB, transpulmonary pressure and characterize the response of the respiratory system to increasing or decreasing PEEP. The "Titrated-PEEP" will be identified as the PEEP level associated with the lowest value of respiratory system elastance and an end expiratory transpulmonary pressure of 2 cmH2O. Then the participants will have two spontaneous breathing trials; one at PEEP 0-5 cmH2O, and the other at the "Titrated-PEEP" level, with PSV=0 and FiO2 unchanged. After extubation, the participants will first receive CPAP set at "Titrated-PEEP", then spontaneous breathing. Electrical impedance tomography (EIT), respiratory system mechanics and gas exchange will be recorded during the study.

The investigators believe that the real-time determination of "Titrated-PEEP" can guide the treatment of mechanical ventilation and give us a better understanding of the physiology and pathophysiology of morbidly obese patients. As a result, this study will improve patient safety; reduce the duration of mechanical ventilation, complications and healthcare costs.

Conditions: Obesity
Being tested: Positive end-expiratory pressure (PEEP), ZEEP
Keywords: Mechanical ventilation, Positive end-expiratory pressure, Work of breathing, Morbidly obese
Medical subject headings: Obesity

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Positive end-expiratory pressure (PEEP)Procedure or surgery
"Titrated-PEEP". After recruitment maneuver and decremental PEEP trial, the "Titrated-PEEP" is identified. Patients will have two spontaneous breathing trials (SBTs). In this arm, patients will have SBT at "Titrated-PEEP", with the PSV=0 and FiO2 unchanged.
ZEEPProcedure or surgery
After recruitment maneuver and decremental PEEP trial, the "Titrated-PEEP" is identified. Patients will have two spontaneous breathing trials (SBTs). In this arm, patients will have SBT at PEEP = 0-5 cmH2O, with the PSV=0 and FiO2 unchanged.

Study groups in NCT02492113
Study group	Role	What they receive
Patients with BMI > 35	Experimental	ICU patients with a BMI > 35, on pressure support ventilation, scheduled for spontaneous breathing trial for evaluation of extubation After recruitment maneuver and decremental PEEP trial, the "Titrated-PEEP" is identified. Patients will have two spontaneous breathing trials (SBTs) in randomized order. Either the patient will receive SBT at PEEP = 0-5 cmH2O, with PSV=0 and FiO2 unchanged; or the patient will perform an SBT at "Titrated-PEEP", with the PSV=0 and FiO2 unchanged. Receives: Procedure: Positive end-expiratory pressure (PEEP); Procedure: ZEEP

What is being measured

The primary outcome is the main question the study is designed to answer.

Differences in WOB at titrated PEEP levels vs. ZEEP level
Work Of Breathing measured as J/L and J/min during a Spontaneous Breathing Trial at titrated PEEP vs. Work Of Breathing measured as J/L and J/min during a Spontaneous Breathing Trial at zero PEEP
Measured: 24 hours

Secondary outcomes (6)

Gas Exchange - Oxygenation
Difference in oxygenation as measured in mmHg of PaO2/FiO2 during a Spontaneous Breathing Trial at titrated PEEP and at zero PEEP.
Measured: 24 hours
Gas Exchange - Arterial carbon dioxide
Difference in arterial carbon dioxide as measured in mmHg (PaCO2) during a Spontaneous Breathing Trial at titrated PEEP and at zero PEEP.
Measured: 24 hours
Respiratory Mechanics - Compliance
Difference in Compliance, measured as ml/cmH2O, of the respiratory system, lungs and chest wall during a Spontaneous Breathing Trial at titrated PEEP and at zero PEEP.
Measured: 24 hours
Gas Volume Distribution
Difference in the images of Electric Impedance Tomography measured as relative variation of regional impedance (deltaZ) (i.e. distribution of ventilation) during a Spontaneous Breathing Trial at titrated PEEP and at zero PEEP.
Measured: 24 hours
Hemodynamics - Blood pressure
Changes in arterial blood pressures (BP, mmHg) during a Spontaneous Breathing Trial at titrated PEEP and at zero PEEP.
Measured: 24 hours
Hemodynamics - Heart rate
Changes in heart rate (HR, bpm) during a Spontaneous Breathing Trial at titrated PEEP and at zero PEEP.
Measured: 24 hours

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

Nov 201524 Nov 2025

First posted8 Jul 2015 (estimated)
Study startNov 2015
Primary completion24 Nov 2025
Study completion24 Nov 2025

Why it stopped: Lack of funding

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.
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: Treatment
Allocation: Not applicable
Intervention model: Single group
Enrolment: 0 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT02492113
Sponsor's protocol ID: WOBTRIAL
Status last verified: Feb 2026
First submitted: 12 Jun 2015
Last updated: 20 Feb 2026
Results posted: No
Data monitoring committee: No

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

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All Obesity trials

Study at a glance

From the registry record, last updated by the sponsor on 20 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Effects of Different PEEP Levels on Work of Breathing in Morbidly Obese Patients Prior to and After Extubation
ClinicalTrials.gov ID: NCT02492113
Acronym / sponsor ID: WOBTRIAL
Conditions: Obesity
Keywords: Mechanical ventilation, Positive end-expiratory pressure, Work of breathing, Morbidly obese
Study type: Interventional
Recruitment status: WithdrawnReason stopped: Lack of funding
Enrolment: 0 participants (actual)
Lead sponsor: Massachusetts General HospitalUniversity, hospital or other
Study start: Nov 2015
Primary completion: 24 Nov 2025 (actual)
Study completion: 24 Nov 2025 (actual)
First posted: 8 Jul 2015 (estimated)
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 main purpose of this study is to define at the bedside the "Titrated-PEEP" level for obese patients that increases the likelihood of extubation and ventilator liberation.

Detailed description

Study design

Primary purpose: Treatment
Allocation: Not applicable
Intervention model: Single group
Number of arms: 1

Arm	Type	Receives
Patients with BMI > 35	Experimental	Procedure: Positive end-expiratory pressure (PEEP), Procedure: ZEEPICU patients with a BMI > 35, on pressure support ventilation, scheduled for spontaneous breathing trial for evaluation of extubation After recruitment maneuver and decremental PEEP trial, the "Titrated-PEEP" is identified. Patients will have two spontaneous breathing trials (SBTs) in randomized order. Either the patient will receive SBT at PEEP = 0-5 cmH2O, with PSV=0 and FiO2 unchanged; or the patient will perform an SBT at "Titrated-PEEP", with the PSV=0 and FiO2 unchanged.

Who may qualify

Ages: 18 years and older
Sex: All
Healthy volunteers: Not accepted
Age groups: Adult, Older adult

Key inclusion criteria (4 listed)

Intubated and mechanically ventilated;
Weaning from mechanical ventilation;
BMI ≥ 35 kg/m2 with waist circumference > 88 cm for women; waist circumference > 102 cm for men.
A well functioning arterial line.

Key exclusion criteria (7 listed)

Known presence of esophageal varices
Recent esophageal trauma or surgery
Severe thrombocytopenia (PTL ≤ 5,000/mm3)
Severe coagulopathy (INR ≥ 4)
Presence of pneumothorax

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
Positive end-expiratory pressure (PEEP)"Titrated-PEEP". After recruitment maneuver and decremental PEEP trial, the "Titrated-PEEP" is identified. Patients will have two spontaneous breathing trials (SBTs). In this arm, patients will have SBT at "Titrated-PEEP", with the PSV=0 and FiO2 unchanged.	Procedure or surgery	Patients with BMI > 35
ZEEPAfter recruitment maneuver and decremental PEEP trial, the "Titrated-PEEP" is identified. Patients will have two spontaneous breathing trials (SBTs). In this arm, patients will have SBT at PEEP = 0-5 cmH2O, with the PSV=0 and FiO2 unchanged.	Procedure or surgery	Patients with BMI > 35

Primary outcome

Differences in WOB at titrated PEEP levels vs. ZEEP level
Time frame: 24 hours
Work Of Breathing measured as J/L and J/min during a Spontaneous Breathing Trial at titrated PEEP vs. Work Of Breathing measured as J/L and J/min during a Spontaneous Breathing Trial at zero PEEP

6 secondary outcomes

Gas Exchange - Oxygenation
Time frame: 24 hours
Gas Exchange - Arterial carbon dioxide
Time frame: 24 hours
Respiratory Mechanics - Compliance
Time frame: 24 hours
Gas Volume Distribution
Time frame: 24 hours
Hemodynamics - Blood pressure
Time frame: 24 hours
Hemodynamics - Heart rate
Time frame: 24 hours

Results and safety

The study was withdrawn before enrolling participants, so there are no results.

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 20 Feb 2026.

Related trials for Obesity

RecruitingObservational study
Endoscopic Sleeve Gastroplasty (ESG) Prospective Trial for Obesity (EGO-Trial)
Obesity
Active, not recruitingPhase 4
Effects of Sequential Therapy With Mexidol® (Intravenous) and Mexidol® FORTE 250 (Oral) on Functional Brain Activity Assessed by Functional Magnetic Resonance Imaging and Biochemical Parameters in Patients With Chronic Cerebral Ischemia: A Comparison of Patients With and Without Metabolic Disorders
Metabolic Abnormalities, Obesity & Overweight
Recruiting
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Recruiting
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Active, not recruiting
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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.

Robert Kacmarek, RRT, PhD principal investigator

Massachusetts General Hospital

Lorenzo Berra, MD principal investigator

Massachusetts General 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 Positive end-expiratory pressure (PEEP) and ZEEP in people with Obesity, run by Massachusetts General Hospital at 1 site in United States.

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: withdrawn, as of the sponsor's last update on 20 Feb 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 United States. 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 was withdrawn before enrolling participants, so there are no results.

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?

Differences in WOB at titrated PEEP levels vs. ZEEP level (time frame: 24 hours). 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 NCT02492113.

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 20 Feb 2026.