EIT-guided PEEP Titration Versus Standard Ventilation in Bariatric Surgery

NCT07207772 | Recruiting

• 1 other identifier: YXLL-KY-2025(107)
• Study Type: interventional
• Target: 118
• Locations: 1 country
• Sites: 1

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.

Conditions

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

Keywords

Electrical Impedance Tomography (EIT); Postoperative Pulmonary Complications (PPCs); Lung protective ventilation strategy; Recruitment manoeuvre(RM); Conventional lung-protective ventilation; bariatric

Outcome Measures

Primary Outcomes (1)

• incidence of postoperative pulmonary complications

  Participants who developed at least one complication are considered as meeting the primary outcome. The PPCs are defined as follows : 1. . Pneumonia (using to the US Centres for Disease Control Criteria ; 2. . Respiratory failure 3. . Bronchospasm (newly detected expiratory wheezing treated with bronchodilators); 4. . Pleural effusion 5. . Pneumothorax 6. . Atelectasis 7. . Pulmonary aspiration 8. . Cardiogenic pulmonary oedema (clinical signs of congestion, including dyspnoea, oedema, rales, and jugular venous distention, with chest X-ray demonstrating an increase in vascular markings and diffuse alveolar interstitial infiltrates).

  postoperative within 72 hours

Secondary Outcomes (3)

• The point-of-care lung ultrasound (LUS) score

  at 30 minutes after endotracheal extubation, 8:00 AM on postoperative day 1 (POD 1) and postoperative day 2 (POD2).

• The severity of PPCs:

  postoperative within 72 hours

• Arterial blood gas analysis

  5 minutes post-intubation (before recruitment maneuver), 1 hour after PNP, at surgery conclusion, and 30 minutes post-extubation.

Study Arms (2)

group P-eit

EXPERIMENTAL

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.

Device: Group P-eit

group P-8

ACTIVE COMPARATOR

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.

Device: Group P-8

Interventions

Group P-eit 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.

Also known as: PEEP Titration guided by EIT

group P-eit

Group P-8 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.

Also known as: fixed peep =8cmH2O

group P-8

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age between 18 and 65 years;
• Plan to receive laparoscopic bariatric surgery under general anesthesia;
• American Society of Anaesthesiologists (ASA) physical status I-III;
• BMI between 30 and 55 kg/m2;
• Voluntary participation in this study and signing of an informed consent form.

You may not qualify if:

• History of smoking or previous thoracic surgery;
• Invasive mechanical ventilation within 30 days;
• Pregnancy;
• Allergy to EIT electrodes;
• Persistent hemodynamic instability or refractory shock;
• 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);
• Severe pulmonary hypertension (systolic pulmonary artery pressure \>40 mmHg);
• Increased intracranial pressure, intracranial injury/tumor, or neuromuscular disorders;
• Conversion to laparotomy;
• Planned transfer to intensive care unit after surgery.

Sponsors & Collaborators

• Jianbo Wu: lead

Study Sites (1)

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

Jinan, Shandong, 0531, China

RECRUITING

MeSH Terms

Conditions

Obesity

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• NA GUO, MS.

  Shandong First Medical University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Jian bo Wu, PH.D

CONTACT

18560083793; jianbowu@126.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: In group C, 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.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: professor

Model Details: In group P, after the titration is completed, the ventilator parameters (tidal volume, respiratory rate, and inspiratory-to-expiratory ratio) will be adjusted back to their pre-recruitment settings. 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. The respiratory rate will be adjusted to maintain end-tidal carbon dioxide partial pressure at 35 to 45 mmHg during the operation process. A second recruitment maneuver, identical to the first, will be performed at the end of the procedure.

Study Record Dates

• First Submitted: September 19, 2025
• First Posted: October 6, 2025
• Study Start: July 28, 2025
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2027
• Last Updated: October 6, 2025

Record last verified: 2025-09

Locations

CN (1)