Mechanical Ventilation in Obese Surgical Patients
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
- Obese
Eligibility
- Eligible Ages
- Over 18 Years
- Eligible Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- 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
- 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
| Arm | Description | Assigned 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. |
|
|
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
Galveston, Texas 77555
More Details
- Status
- Recruiting
- Sponsor
- The University of Texas Medical Branch, Galveston