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Purpose

The purpose of this study is to evaluate whether an intraoperative positive end-expiratory pressures (PEEP) setting strategy aimed at minimizing the mechanical power delivered to the lungs via transpulmonary pressure improves postoperative outcomes in obese patients undergoing conventional laparoscopic or robotic-assisted surgery. The objectives are to determine whether this strategy reduces immediate postoperative hypoxemia, and to assess whether it mitigates lung injury as reflected by relevant blood biomarkers.

Condition

Eligibility

Eligible Ages
Over 18 Years
Eligible Sex
All
Accepts Healthy Volunteers
No

Inclusion Criteria

  1. Age ≥ 18 years; 2. Body Mass Index (BMI) ≥ 35 kg/m2; 3. Scheduled for laparoscopic surgery expected to exceed 2h (from incision to closure) under general anesthesia, as determined pre-operatively by the attending surgeon and surgical team based on typical scheduling estimates, prior experience, procedure type, planned surgical approach, and patient-specific factors.

Exclusion Criteria

  1. Previous lung surgery; 2. Invasive mechanical ventilation for >30 minutes within the last 30 days prior to surgery; 3. Receipt of immunosuppressive medication (chemotherapy or radiotherapy) up to two months prior to surgery; 4. Neurological procedures or cardiac surgery; 5. Need for one-lung ventilation or planned re-intubation following surgery; 6. Requirement for intraoperative prone or lateral decubitus positioning; 7. Enrollment in another interventional study or refusal to give written informed consent; 8. Pregnancy, determined by anamnesis and/or laboratory testing; 9. Persistent hemodynamic instability or intractable shock, considered hemodynamically unsuitable for the study by the patient's managing physician; 10. Severe chronic obstructive pulmonary disease (COPD, defined as non-invasive ventilation and/or oxygen therapy at home or repeated systemic corticosteroid therapy for acute exacerbations of COPD); 11. Severe cardiac disease (defined as New York Heart Association class III or IV, acute coronary syndrome or persistent ventricular tachyarrhythmia); 12. Acute respiratory distress syndrome (according to the Berlin definition 2) expected to require prolonged postoperative mechanical ventilation; 13. Severe pulmonary arterial hypertension (defined as systolic pulmonary artery pressure > 40 mmHg) 14. Intracranial injury, intracranial tumor, or neuromuscular disease; 15. Known esophageal disease or anatomy that would preclude the safe placement of a standard orogastric tube

Study Design

Phase
N/A
Study Type
Interventional
Allocation
Randomized
Intervention Model
Parallel Assignment
Primary Purpose
Prevention
Masking
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
Transpulmonary Pressure-Guided Individualized PEEP 		A transpulmonary-guided individualized positive end-expiratory pressure (PEEPPTP) will be set as follows: (A) The intervention is initiated by a recruitment maneuver consisting of 5 cmH2O-stepwise (30 sec) PEEP increases until either maximum PEEP=30 cmH2O or end-inspiratory PTP>25 cmH2O is reached. Settings: volume-controlled ventilation, VT=7ml/kg, I:E=1:1, inspiratory pause=20%, RR=10bpm, FiO2=80%. (B) Following recruitment, PEEP will be set to the value used immediately before the recruitment maneuver and PEso-EE assessed. PEEPPTP=PEso-EE+1-2 cmH2O. (C) PEEP will then be set for 30 sec at the highest value achieved during recruitment, followed by (D) PEEPPTP. Individualized PEEP-setting will be performed after: (1) induction of anesthesia, (2) pneumoperitoneum and final surgical position, including Trendelenburg and robot docking, (3) significant airway pressure changes or >15% reduction in compliance (CRS=VT/DP), and (4) before extubation.
  • Procedure: Standard PEEP (8 cmH₂O)
    Participants will receive standard intraoperative mechanical ventilation with a fixed positive end-expiratory pressure (PEEP) of 8 cmH₂O maintained throughout the surgical procedure.
No Intervention
Control Group - Standard Intraoperative PEEP 		PEEP will be set to currently accepted settings for intraoperative PEEP=8cmH2O.

Recruiting Locations

University of Texas Medical Branch, Galveston
Galveston, Texas 77555
Contact:
Negar Motayagheni
nemotaya@utmb.edu

More Details

Status
Recruiting
Sponsor
The University of Texas Medical Branch, Galveston

Study Contact

Negar Motayagheni
(409)772-1011
nemotaya@utmb.edu

Notice

Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.