Morbid ObesityNCT07542093
Bedside Lung Ultrasound to Monitor Lung Recruitment in Obese Patients
An observational study of Morbid Obesity and Obesity, run by Assiut University.
Trial summary
Patients with morbid obesity who require a breathing machine (mechanical ventilator) in the Intensive Care Unit (ICU) frequently experience partial lung collapse. This happens because the extra weight of the chest and abdomen presses on the lungs, reducing their capacity and making it difficult to maintain adequate… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Morbid Obesity, Obesity, Respiratory Failure
- How many people
- 45 participants
- Where
- No sites listed yet
- Study dates
- May 2026to Jun 2027
- Phase
- Observational
- 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
- Adult, Older adult
Study population: The study population consists of adult patients (aged >18 years) with morbid obesity (BMI ≥ 33 kg/m²) who are admitted to the respiratory Intensive Care Unit (ICU) at Assiut University Hospital. Patients must be intubated and receiving invasive mechanical ventilation for an expected duration of at least 6 hours, while maintaining hemodynamic stability at enrollment.
Who may be able to join
- Adult patients aged >18 years
- BMI ≥ 33 kg/m² (morbid obesity)
- Intubated and receiving invasive mechanical ventilation for any indication (elective surgery, respiratory failure, post-operative ICU admission)
- Expected duration of mechanical ventilation ≥ 6 hours
- Hemodynamically stable at enrollment: Mean Arterial Pressure (MAP) ≥ 65 mmHg without escalating vasopressor support
- SpO₂ ≥ 85% on current ventilator settings
- Written informed consent obtained from patient or legal guardian
Who cannot join
- Known or suspected pneumothorax or bullous emphysema (contraindication to recruitment maneuvers)
- Severe hemodynamic instability: MAP < 60 mmHg or requiring high-dose vasopressors (norepinephrine > 0.3 mcg/kg/min)
- Active bronchopleural fistula
- Recent thoracic or cardiac surgery (within 48 hours) where high airway pressures are contraindicated
- Raised intracranial pressure (ICP) or known severe traumatic brain injury
- Confirmed ARDS with PaO₂/FiO₂ ratio < 100 mmHg (severe ARDS, where recruitment strategy differs significantly)
- Chest wall deformity or subcutaneous emphysema that precludes reliable lung ultrasound assessment
- Refusal of consent
About this study
Official title: Use of Bedside Lung Ultrasound to Monitor Lung Recruitment Maneuvers During Mechanical Ventilation in Obese Patients
Patients with morbid obesity who require a breathing machine (mechanical ventilator) in the Intensive Care Unit (ICU) frequently experience partial lung collapse. This happens because the extra weight of the chest and abdomen presses on the lungs, reducing their capacity and making it difficult to maintain adequate oxygen levels. To address this, doctors often perform a standard lung recruitment maneuver, which involves temporarily increasing the air pressure from the ventilator to gently pop open the collapsed lung areas. However, standard bedside monitoring tools make it difficult to see exactly how well the different regions of the lungs are reopening.
This prospective observational study aims to evaluate the use of Bedside Lung Ultrasound (LUS), which is a safe, radiation-free imaging tool, to monitor how well the lungs respond to these maneuvers in real-time.
During the study, researchers will use a standardized 12-zone ultrasound scan to examine the lungs of mechanically ventilated adult patients (BMI ≥ 33 kg/m²) before, during, and after a step-by-step lung recruitment maneuver. By calculating a "Total Lung Ultrasound Score," the medical team can directly visualize and measure the transition from collapsed tissue to normal, aerated lung tissue. Furthermore, the ultrasound will be used during a step-down pressure phase to help identify the patient's "optimal PEEP" (Positive End-Expiratory Pressure), which is the exact customized pressure needed to keep the lungs open after the maneuver is complete, thereby improving oxygenation and minimizing the risk of lung injury.
Read the detailed description
The global escalation of obesity creates distinct challenges for respiratory management in the ICU. In the morbidly obese population, increased chest wall mass and cranial displacement of the diaphragm significantly elevate pleural pressure. This physiological burden leads to widespread atelectasis in dependent lung zones and a marked reduction in functional residual capacity, resulting in a cycle of atelectrauma and severe ventilation-perfusion mismatch. Traditional monitoring tools are inadequate for managing these patients: chest X-rays lack sensitivity for detecting posterior, dependent-zone collapse, Computed Tomography (CT) carries prohibitive transport risks and radiation exposure, and conventional compliance curves provide only global information that obscures regional heterogeneity. Bedside Lung Ultrasound (LUS) offers a paradigm shift by enabling real-time regional visualization of sub-pleural pathology, allowing clinicians to identify the transition from tissue-like consolidation to normal aeration at the bedside.
This study aims to evaluate the clinical utility of bedside LUS as a real-time, radiation-free monitoring tool for assessing the effectiveness of Lung Recruitment Maneuvers (LRMs) and guiding optimal Positive End-Expiratory Pressure (PEEP) titration in mechanically ventilated obese adults.
Study Procedures:
- Baseline Assessment: Following enrollment, baseline ventilator parameters, hemodynamics, Arterial Blood Gas (ABG), static lung compliance, and driving pressure are recorded. A standardized 12-zone LUS scan is performed. Each zone is scored from 0 (A-lines predominant/normal aeration) to 3 (tissue-like consolidation/complete collapse) to calculate a total baseline LUS score.
- Pre-Maneuver Checkpoint: Prior to initiating the maneuver, strict hemodynamic safety criteria must be confirmed, including a Mean Arterial Pressure (MAP) ≥ 65 mmHg, Heart Rate between 60-120 bpm, and SpO₂ ≥ 85%.
- Stepwise Recruitment Maneuver: Ventilation is switched to Pressure Control (PCV) with a constant driving pressure of 15 cmH₂O. PEEP is systematically increased in 2 cmH₂O increments from 10 to a peak of 20 cmH₂O, holding each step for 5 minutes. During each step, a focused 2-zone posterior-basal LUS scan is performed bilaterally.
- Decremental PEEP Titration: Following peak recruitment, PEEP is reduced by 2 cmH₂O every 5 minutes. A focused 4-zone posterior LUS scan is performed at each step to identify the "Closing Pressure," which is the exact PEEP level where B-lines or consolidation reappear in previously aerated zones. Optimal PEEP is calculated as the Closing Pressure plus 2 cmH₂O. A brief re-recruitment is performed before setting this final optimal PEEP.
- Post-Maneuver Assessment: At 15-20 minutes after establishing the optimal PEEP, a full 12-zone LUS scan is repeated to calculate the post-maneuver score. Follow-up ABG, static compliance, driving pressure, and hemodynamic measurements are also recorded.
Scanning is performed by the same trained investigator throughout the study to reduce inter-observer variability, and safety stop criteria are in place to abort the maneuver if patients exhibit severe desaturation, hemodynamic instability, or signs of pneumothorax.
- Conditions
- Morbid Obesity, Obesity, Respiratory Failure, Atelectasis, Ventilator-Induced Lung Injury (VILI)
- Keywords
- Lung Ultrasound (LUS), Lung Ultrasound Score, Lung Recruitment Maneuvers (LRM), Mechanical Ventilation, Positive End-Expiratory Pressure (PEEP), Optimal PEEP, Decremental PEEP Titration
- Medical subject headings
- Obesity, Morbid, Obesity, Respiratory Insufficiency, Pulmonary Atelectasis, Ventilator-Induced Lung Injury
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Mechanically Ventilated Obese Patients | Adult patients with a BMI ≥ 33 kg/m² requiring invasive mechanical ventilation in the respiratory ICU. All participants in this single-cohort study will undergo a standardized, stepwise pressure-controlled lung recruitment maneuver reaching a peak inspiratory pressure of 35 cmH₂O and a PEEP of 20 cmH₂O. This is immediately followed by a decremental PEEP titration. The primary observational focus is the use of a bedside 12-zone Lung Ultrasound (LUS) scan to monitor real-time regional lung re-aeration, calculate total LUS scores before and after the maneuver, and identify the optimal PEEP based on lung closing pressures. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Total Lung Ultrasound Score (LUS)
The Total Lung Ultrasound Score (LUS) assesses regional lung aeration using a 12-zone scanning protocol. Each of the 12 zones is scored from 0 (normal aeration) to 3 (complete collapse/tissue-like consolidation). The total score is the sum of all 12 zones, ranging from 0 to 36, where a higher score indicates worse lung aeration. This measure evaluates the quantitative change in real-time regional re-aeration resulting from the lung recruitment maneuver.
Measured: Baseline (immediately before the recruitment maneuver) to 15-20 minutes after establishing optimal PEEP
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Apr 2026
- Study startMay 2026 (estimated)
- Primary completionMay 2027 (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 Morbid ObesityStudies of the same condition, open and under way.
- More trials run by Assiut UniversityThe 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 45 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Assiut University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Asmaa Mostafa Hammam, Assiut University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07542093
- Sponsor's protocol ID
- US: Obese Lung Recruitment
- Status last verified
- Apr 2026
- First submitted
- 14 Apr 2026
- Last updated
- 21 Apr 2026
- Results posted
- No
Study at a glance
From the registry record, last updated by the sponsor on 21 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Use of Bedside Lung Ultrasound to Monitor Lung Recruitment Maneuvers During Mechanical Ventilation in Obese Patients
- ClinicalTrials.gov ID
- NCT07542093
- Acronym / sponsor ID
- US: Obese Lung Recruitment
- Conditions
- Morbid Obesity, Obesity, Respiratory Failure, Atelectasis, Ventilator-Induced Lung Injury (VILI)
- Keywords
- Lung Ultrasound (LUS), Lung Ultrasound Score, Lung Recruitment Maneuvers (LRM), Mechanical Ventilation, Positive End-Expiratory Pressure (PEEP), Optimal PEEP, Decremental PEEP Titration
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 45 participants (estimated)
- Lead sponsor
- Assiut UniversityUniversity, hospital or other
- Study start
- May 2026 (estimated)
- Primary completion
- May 2027 (estimated)
- Study completion
- Jun 2027 (estimated)
- First posted
- 21 Apr 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.
Patients with morbid obesity who require a breathing machine (mechanical ventilator) in the Intensive Care Unit (ICU) frequently experience partial lung collapse. This happens because the extra weight of the chest and abdomen presses on the lungs, reducing their capacity and making it difficult to maintain adequate oxygen levels. To address this, doctors often perform a standard lung recruitment maneuver, which involves temporarily increasing the air pressure from the ventilator to gently pop open the collapsed lung areas. However, standard bedside monitoring tools make it difficult to see exactly how well the different regions of the lungs are reopening.
This prospective observational study aims to evaluate the use of Bedside Lung Ultrasound (LUS), which is a safe, radiation-free imaging tool, to monitor how well the lungs respond to these maneuvers in real-time.
During the study, researchers will use a standardized 12-zone ultrasound scan to examine the lungs of mechanically ventilated adult patients (BMI ≥ 33 kg/m²) before, during, and after a step-by-step lung recruitment maneuver. By calculating a "Total Lung Ultrasound Score," the medical team can directly visualize and measure the transition from collapsed tissue to normal, aerated lung tissue. Furthermore, the ultrasound will be used during a step-down pressure phase to help identify the patient's "optimal PEEP" (Positive End-Expiratory Pressure), which is the exact customized pressure needed to keep the lungs open after the maneuver is complete, thereby improving oxygenation and minimizing the risk of lung injury.
Detailed description
The global escalation of obesity creates distinct challenges for respiratory management in the ICU. In the morbidly obese population, increased chest wall mass and cranial displacement of the diaphragm significantly elevate pleural pressure. This physiological burden leads to widespread atelectasis in dependent lung zones and a marked reduction in functional residual capacity, resulting in a cycle of atelectrauma and severe ventilation-perfusion mismatch. Traditional monitoring tools are inadequate for managing these patients: chest X-rays lack sensitivity for detecting posterior, dependent-zone collapse, Computed Tomography (CT) carries prohibitive transport risks and radiation exposure, and conventional compliance curves provide only global information that obscures regional heterogeneity. Bedside Lung Ultrasound (LUS) offers a paradigm shift by enabling real-time regional visualization of sub-pleural pathology, allowing clinicians to identify the transition from tissue-like consolidation to normal aeration at the bedside.
This study aims to evaluate the clinical utility of bedside LUS as a real-time, radiation-free monitoring tool for assessing the effectiveness of Lung Recruitment Maneuvers (LRMs) and guiding optimal Positive End-Expiratory Pressure (PEEP) titration in mechanically ventilated obese adults.
Study Procedures:
- Baseline Assessment: Following enrollment, baseline ventilator parameters, hemodynamics, Arterial Blood Gas (ABG), static lung compliance, and driving pressure are recorded. A standardized 12-zone LUS scan is performed. Each zone is scored from 0 (A-lines predominant/normal aeration) to 3 (tissue-like consolidation/complete collapse) to calculate a total baseline LUS score.
- Pre-Maneuver Checkpoint: Prior to initiating the maneuver, strict hemodynamic safety criteria must be confirmed, including a Mean Arterial Pressure (MAP) ≥ 65 mmHg, Heart Rate between 60-120 bpm, and SpO₂ ≥ 85%.
- Stepwise Recruitment Maneuver: Ventilation is switched to Pressure Control (PCV) with a constant driving pressure of 15 cmH₂O. PEEP is systematically increased in 2 cmH₂O increments from 10 to a peak of 20 cmH₂O, holding each step for 5 minutes. During each step, a focused 2-zone posterior-basal LUS scan is performed bilaterally.
- Decremental PEEP Titration: Following peak recruitment, PEEP is reduced by 2 cmH₂O every 5 minutes. A focused 4-zone posterior LUS scan is performed at each step to identify the "Closing Pressure," which is the exact PEEP level where B-lines or consolidation reappear in previously aerated zones. Optimal PEEP is calculated as the Closing Pressure plus 2 cmH₂O. A brief re-recruitment is performed before setting this final optimal PEEP.
- Post-Maneuver Assessment: At 15-20 minutes after establishing the optimal PEEP, a full 12-zone LUS scan is repeated to calculate the post-maneuver score. Follow-up ABG, static compliance, driving pressure, and hemodynamic measurements are also recorded.
Scanning is performed by the same trained investigator throughout the study to reduce inter-observer variability, and safety stop criteria are in place to abort the maneuver if patients exhibit severe desaturation, hemodynamic instability, or signs of pneumothorax.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Mechanically Ventilated Obese Patients | – | –Adult patients with a BMI ≥ 33 kg/m² requiring invasive mechanical ventilation in the respiratory ICU. All participants in this single-cohort study will undergo a standardized, stepwise pressure-controlled lung recruitment maneuver reaching a peak inspiratory pressure of 35 cmH₂O and a PEEP of 20 cmH₂O. This is immediately followed by a decremental PEEP titration. The primary observational focus is the use of a bedside 12-zone Lung Ultrasound (LUS) scan to monitor real-time regional lung re-aeration, calculate total LUS scores before and after the maneuver, and identify the optimal PEEP based on lung closing pressures. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Age groups
- Adult, Older adult
- Study population
- The study population consists of adult patients (aged >18 years) with morbid obesity (BMI ≥ 33 kg/m²) who are admitted to the respiratory Intensive Care Unit (ICU) at Assiut University Hospital. Patients must be intubated and receiving invasive mechanical ventilation for an expected duration of at least 6 hours, while maintaining hemodynamic stability at enrollment.
Key inclusion criteria (7 listed)
- Adult patients aged >18 years
- BMI ≥ 33 kg/m² (morbid obesity)
- Intubated and receiving invasive mechanical ventilation for any indication (elective surgery, respiratory failure, post-operative ICU admission)
- Expected duration of mechanical ventilation ≥ 6 hours
- Hemodynamically stable at enrollment: Mean Arterial Pressure (MAP) ≥ 65 mmHg without escalating vasopressor support
Key exclusion criteria (8 listed)
- Known or suspected pneumothorax or bullous emphysema (contraindication to recruitment maneuvers)
- Severe hemodynamic instability: MAP < 60 mmHg or requiring high-dose vasopressors (norepinephrine > 0.3 mcg/kg/min)
- Active bronchopleural fistula
- Recent thoracic or cardiac surgery (within 48 hours) where high airway pressures are contraindicated
- Raised intracranial pressure (ICP) or known severe traumatic brain injury
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Change in Total Lung Ultrasound Score (LUS)
Time frame: Baseline (immediately before the recruitment maneuver) to 15-20 minutes after establishing optimal PEEP
The Total Lung Ultrasound Score (LUS) assesses regional lung aeration using a 12-zone scanning protocol. Each of the 12 zones is scored from 0 (normal aeration) to 3 (complete collapse/tissue-like consolidation). The total score is the sum of all 12 zones, ranging from 0 to 36, where a higher score indicates worse lung aeration. This measure evaluates the quantitative change in real-time regional re-aeration resulting from the lung recruitment maneuver.
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 21 Apr 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.
The record lists no contact. Use the official record to reach the sponsor.
Questions about this trial
What is this clinical trial studying?
An observational study of Morbid Obesity and Obesity, run by Assiut University.
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 8 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 21 Apr 2026. 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. 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?
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 Total Lung Ultrasound Score (LUS) (time frame: Baseline (immediately before the recruitment maneuver) to 15-20 minutes after establishing optimal PEEP). 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 21 Apr 2026.