Bedside Lung Ultrasound to Monitor Lung Recruitment in Obese Patients

NCT07542093 | Not Yet Recruiting

• 1 other identifier: US: Obese Lung Recruitment
• Study Type: observational
• Target: 45
• Locations: 0 countries
• Sites: N/A

Brief 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 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.

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

Outcome Measures

Primary Outcomes (1)

• 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.

  Baseline (immediately before the recruitment maneuver) to 15-20 minutes after establishing optimal PEEP

Study Arms (1)

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.

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

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.

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Assiut University: lead

MeSH Terms

Conditions

Obesity, Morbid; Obesity; Respiratory Insufficiency; Pulmonary Atelectasis; Ventilator-Induced Lung Injury

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Respiration Disorders; Respiratory Tract Diseases; Lung Diseases; Lung Injury

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Resident at Chest Diseases Department, Assiut University

Study Record Dates

• First Submitted: April 14, 2026
• First Posted: April 21, 2026
• Study Start: May 1, 2026
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): June 1, 2027
• Last Updated: April 21, 2026

Record last verified: 2026-04