EIT-guided PEEP Titration Versus Standard Ventilation in Bariatric Surgery

NCT ID: NCT07207772

Last Updated: 2025-10-06

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 118 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-07-28
• Study Completion Date: 2027-12-31

Brief Summary

This study is a prospective, single-center, single-blind, randomized controlled clinical trial. Patients scheduled for laparoscopic bariatric surgery will be selected and randomly assigned to either the EIT-guided individualized PEEP group (Group P-eit) or the control group (Group P-8). Group P will be ventilated using the PEEP value determined by EIT, while Group C will be ventilated with a fixed PEEP value of 8 cmH2O.The primary outcome is the incidence of postoperative pulmonary complications (PPCs) within 72 hours after surgery.

Detailed Description

This is a single-center, single-blind，randomized controlled trial conducted at the First Affiliated Hospital of Shandong First Medical University in Jinan City,Shandong Province, China. This randomized controlled trial has been approved by the Ethics Committee of The First Affiliated Hospital of Shandong First Medical University (YXLL-KY-2025(107)).And it complies with the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) guidelines. A total of 118 participants will be randomly allocated to the EIT-guided individualized PEEP group (Group P ) (n = 59) or the control group (Group C) (n = 59). Recruitment for this study has begun on July 28, 2025, and will continue through the end of 2026.

Conditions

Electrical Impedance Tomography (EIT); Postoperative Pulmonary Complications (PPCs); Recruitment; Mechanical Ventilation Complication; Obesity

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: QUADRUPLE

Study Groups

group P-eit

In group P-eit, EIT electrode patches will be placed before the operation. "The Recruitment Maneuver - PEEP Titration - Recruitment Maneuver (RM-T-R) Strategy" will be implemented 5 minutes after endotracheal intubation. EIT-based optimal PEEP is defined as the crossing point of the overdistension and collapse curves during a decremental PEEP trial. Other parameters include the individualized PEEP value determined by EIT and inspiratory oxygen fraction (FiO2) of 0.5. PEEP value will be maintained throughout the surgery.All patients in the group P-eit will receive i.v. fluid loading before and a norepinephrine bolus by protocol during the RM in order to maintain a mean arterial pressure \>70mm Hg and minimize the short-lasting haemodynamic depression usually observed during the RM.

Group Type: EXPERIMENTAL

Group P-eit

Intervention Type: DEVICE

"The Recruitment Maneuver - PEEP Titration - Recruitment Maneuver (RM-T-R) Strategy" will be implemented 5 minutes after endotracheal intubation. The patient will receive an RM (peak pressure 50cm H2O, PEEP 25cmH2O, respiratory rate 6 bpm, for 10 cycles) followed by a decremental PEEP titration, during which PEEP is set to 25cm H2O and decreased stepwise by 2cm H2O every 3min until reaching 5 cmH₂O. Meanwhile, the ventilator parameters (tidal volume, respiratory rate, and inspiratory-to-expiratory ratio) will be adjusted back to their pre-recruitment settings. EIT-based optimal PEEP is defined as the crossing point of the overdistension and collapse curves during a decremental PEEP trial.

group P-8

In group P-8, mechanical ventilation will be administered in volume-controlled mode with a tidal volume of 8 ml/kg (based on ideal body weight). Additional settings include a PEEP of 8 cmH₂O, FiO₂ of 0.5, an inspiratory-to-expiratory ratio of 1:2, and a respiratory rate of 12 breaths/min. A recruitment maneuver (RM) will be performed 5 minutes after intubation and again after surgery, using the same protocol as in group P. The respiratory rate will be adjusted as needed to maintain end-tidal CO₂ between 35 and 45 mmHg throughout the procedure.

Group Type: ACTIVE_COMPARATOR

Group P-8

Intervention Type: DEVICE

In group p-8, mechanical ventilation will be administered in volume-controlled mode with a tidal volume of 8 ml/kg (based on ideal body weight). Additional settings include a PEEP of 8 cmH₂O, FiO₂ of 0.5, an inspiratory-to-expiratory ratio of 1:2, and a respiratory rate of 12 breaths/min. A recruitment maneuver (RM) will be performed 5 minutes after intubation and again after surgery, using the same protocol as in group P-eit. The respiratory rate will be adjusted as needed to maintain end-tidal CO₂ between 35 and 45 mmHg throughout the procedure.

Interventions

Group P-eit

"The Recruitment Maneuver - PEEP Titration - Recruitment Maneuver (RM-T-R) Strategy" will be implemented 5 minutes after endotracheal intubation. The patient will receive an RM (peak pressure 50cm H2O, PEEP 25cmH2O, respiratory rate 6 bpm, for 10 cycles) followed by a decremental PEEP titration, during which PEEP is set to 25cm H2O and decreased stepwise by 2cm H2O every 3min until reaching 5 cmH₂O. Meanwhile, the ventilator parameters (tidal volume, respiratory rate, and inspiratory-to-expiratory ratio) will be adjusted back to their pre-recruitment settings. EIT-based optimal PEEP is defined as the crossing point of the overdistension and collapse curves during a decremental PEEP trial.

Intervention Type: DEVICE

Group P-8

In group p-8, mechanical ventilation will be administered in volume-controlled mode with a tidal volume of 8 ml/kg (based on ideal body weight). Additional settings include a PEEP of 8 cmH₂O, FiO₂ of 0.5, an inspiratory-to-expiratory ratio of 1:2, and a respiratory rate of 12 breaths/min. A recruitment maneuver (RM) will be performed 5 minutes after intubation and again after surgery, using the same protocol as in group P-eit. The respiratory rate will be adjusted as needed to maintain end-tidal CO₂ between 35 and 45 mmHg throughout the procedure.

Intervention Type: DEVICE

Other Intervention Names

PEEP Titration guided by EIT; fixed peep =8cmH2O

Eligibility Criteria

Inclusion Criteria

1. Age between 18 and 65 years;

2. Plan to receive laparoscopic bariatric surgery under general anesthesia;

3. American Society of Anaesthesiologists (ASA) physical status I-III;

4. BMI between 30 and 55 kg/m2;

5. Voluntary participation in this study and signing of an informed consent form.

Exclusion Criteria

1. History of smoking or previous thoracic surgery;

2. Invasive mechanical ventilation within 30 days;

3. Pregnancy;

4. Allergy to EIT electrodes;

5. Persistent hemodynamic instability or refractory shock;

6. Severe cardiopulmonary disease (e.g., severe COPD (Chronic obstructive pulmonary disease), NYHA (New York Heart Association) Class III or IV, acute coronary syndrome, or sustained ventricular tachycardia);

7. Severe pulmonary hypertension (systolic pulmonary artery pressure >40 mmHg);

8. Increased intracranial pressure, intracranial injury/tumor, or neuromuscular disorders;

9. Conversion to laparotomy;

10. Planned transfer to intensive care unit after surgery.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Jianbo Wu

OTHER

Sponsor Role: lead

Responsible Party

Jianbo Wu

professor

Responsibility Role: SPONSOR_INVESTIGATOR

Principal Investigators

NA GUO, MS.

Role: PRINCIPAL_INVESTIGATOR

Shandong First Medical University

Locations

The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital

Jinan, Shandong, China

Site Status: RECRUITING

Countries

China

Central Contacts

Jian bo Wu, PH.D

Role: CONTACT

jianbowu@126.com

18560083793

Facility Contacts

NA GUO

Role: primary

xinzangbianshu@163.com

18615605135

Other Identifiers

YXLL-KY-2025(107)

Identifier Type: -

Identifier Source: org_study_id