EIT-guided PEEP Titration Versus Standard Ventilation in Bariatric Surgery

Jianbo Wu

Status: Enrolling

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

Treatments: Device: Group P-8; Device: Group P-eit

Study type: Interventional

Funder types: Other

Identifiers

NCT07207772

YXLL-KY-2025(107)

Details and patient eligibility

About

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.

Full 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.

Enrollment: 118 estimated patients

Sex: All

Ages: 18 to 65 years old

Volunteers: No Healthy Volunteers

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.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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118 participants in 2 patient groups

group P-eit

Experimental group

Description:

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.

Treatment:

Device: Group P-eit

group P-8

Active Comparator group

Description:

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.

Treatment:

Device: Group P-8