PEEP Titration Guided by Electrical Impedance Tomography in Laparoscopic Surgery The PEaRL Study (PEaRL)

December 4, 2025 updated by: Tommaso Fossali, ASST Fatebenefratelli Sacco

Personalized PEEP Titration Guided by Electrical Impedance Tomography in Patients Undergoing Laparoscopic Surgery: A Randomized Controlled Trial - The PEaRL Study

Background:

Laparoscopic surgery has gained widespread adoption due to its minimally invasive nature, offering advantages such as reduced postoperative pain, shorter hospitalization, and faster functional recovery compared with traditional open surgery. Nevertheless, postoperative respiratory complications remain a major source of morbidity. Factors such as general anesthesia, the Trendelenburg position, and CO₂ pneumoperitoneum can impair respiratory mechanics, reduce total lung capacity, and promote atelectasis, leading to compromised gas exchange.

Rationale:

Positive end-expiratory pressure (PEEP) is routinely applied to prevent alveolar collapse and improve oxygenation during mechanical ventilation. However, the use of standardized, non-individualized PEEP levels may be suboptimal, as inappropriate settings can cause alveolar overdistension or persistent collapse. Personalized PEEP titration, tailored to patient-specific lung mechanics, has recently emerged as a promising strategy to minimize ventilator-induced lung injury (VILI).

Methods and Tools:

Electrical Impedance Tomography (EIT) is a non-invasive, bedside monitoring technique that enables real-time assessment of regional lung ventilation. By evaluating ventilated and non-ventilated lung areas, EIT can guide PEEP optimization and support individualized ventilatory management. Recent studies suggest that EIT-guided PEEP titration improves respiratory parameters and reduces atelectasis in patients undergoing major surgery.

Objective:

The present study aims to evaluate the efficacy of EIT-guided PEEP personalization in patients undergoing laparoscopic and robotic surgery. Primary endpoints include improvements in regional ventilation, respiratory system compliance, and intraoperative gas exchange, as well as postoperative pulmonary function.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Laparoscopic surgery has become an increasingly widespread surgical approach due to its minimally invasive nature, which allows for reduced postoperative pain, shorter hospital stays, and faster functional recovery compared to traditional open surgery. However, despite these advantages, laparoscopic procedures are not free from postoperative respiratory complications, which remain among the leading causes of postoperative morbidity. The combination of general anesthesia, the Trendelenburg position, and insufflation of CO₂ into the abdominal cavity can alter respiratory mechanics, reduce total lung capacity, and promote the development of atelectatic areas, resulting in impaired gas exchange (1-2).

Positive end-expiratory pressure (PEEP) is a widely used strategy to prevent alveolar collapse and improve oxygenation during mechanical ventilation. Nevertheless, the application of a standardized, non-individualized PEEP level may not be optimal for all patients, and an inappropriate PEEP setting may lead to alveolar overdistension or persistence of collapsed areas (3). Recently, personalized PEEP titration has gained attention as a method to tailor ventilation settings to individual patient characteristics, thereby minimizing the risk of ventilator-induced lung injury (VILI) (4).

Electrical Impedance Tomography (EIT) is a non-invasive, bedside imaging technique that enables real-time assessment of the regional distribution of pulmonary ventilation. EIT allows continuous monitoring of the effects of PEEP on both ventilated and non-ventilated lung regions and can guide the optimization of individualized PEEP levels to improve ventilation distribution and reduce the risk of respiratory complications (5-6). Recent studies have shown that the use of EIT-guided PEEP personalization in patients undergoing major surgery can improve respiratory parameters and reduce atelectasis formation (7-8). Specifically, EIT enables the performance of a PEEP trial, during which the device identifies areas of alveolar overdistension or collapse in response to PEEP changes, thereby guiding personalized ventilatory settings.

However, the application of this technique in the context of laparoscopic surgery remains limited. This study aims to evaluate the effectiveness of EIT-guided PEEP personalization in patients undergoing laparoscopic and robotic procedures, with the goal of improving regional ventilation, respiratory system compliance, and intraoperative gas exchange, as well as postoperative pulmonary function.

Study Type

Interventional

Enrollment (Estimated)

52

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

  • Name: Luigi Guglielmetti, MD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • scheduled for laparoscopic abdominal surgery
  • informed consent signed

Exclusion Criteria:

  • COPD
  • Acute respiratory failure
  • Hemodynamic instability
  • Pregnancy
  • Contraindications for EIT device

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
No Intervention: Standard PEEP
PEEP value will be decided by clinician
Experimental: EIT PEEP
PEEP value will be set after a PEEP trial performed with EIT machine
Device: A PEEP trial performed with the PulmoVista® 500 (Dräger, Lübeck, Germany) is a procedure designed to identify the optimal level of positive end-expiratory pressure

During the trial, stepwise adjustments of PEEP are made while EIT provides real-time, bedside visualization of ventilation distribution across different lung regions. Typically, the protocol involves a recruitment maneuver followed by incremental and/or decremental PEEP steps (for example, in 2-3 cmH₂O intervals). At each step, EIT measures changes in regional impedance, which reflect variations in local lung aeration and ventilation.

By analyzing these parameters, clinicians can determine the individualized "best PEEP", defined as the point at which alveolar collapse is minimized without causing significant overdistension. The optimal PEEP is then set for subsequent ventilation management.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Static respiratory system compliance
Time Frame: - Baseline (after anesthesia induction) - T1 (After Trendelemburg position and induction of pneumoperitoneum) - T2 (After PEEP trial) - T3 (90 minutes after PEEP trial) - T4 (180 minutes after PEEP trial) - T5 (Before end of anesthesia)
Respiratory system compliance is equivalent to tidal volume divided by the diiference between plateau and PEEP pressure. Unit of measurement is cmH2O/mL
- Baseline (after anesthesia induction) - T1 (After Trendelemburg position and induction of pneumoperitoneum) - T2 (After PEEP trial) - T3 (90 minutes after PEEP trial) - T4 (180 minutes after PEEP trial) - T5 (Before end of anesthesia)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

ASST Fatebenefratelli Sacco

Investigators

  • Principal Investigator: Tommaso Fossali, MD, Asst Fatebenefratelli Sacco

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

January 1, 2026

Primary Completion (Estimated)

October 1, 2026

Study Completion (Estimated)

November 1, 2026

Study Registration Dates

First Submitted

November 19, 2025

First Submitted That Met QC Criteria

December 4, 2025

First Posted (Actual)

December 17, 2025

Study Record Updates

Last Update Posted (Actual)

December 17, 2025

Last Update Submitted That Met QC Criteria

December 4, 2025

Last Verified

October 1, 2025

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • CET 341-2025

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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