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NCT Number: NCT07289113

PEEP Titration Guided by Electrical Impedance Tomography in Laparoscopic Surgery 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.

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Key information

Conditions

Electrical Impedance Tomography

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Department of Anesthesia and Intensive Care Medicine

Milan, Lombardy, 20154, Italy

Location status: Recruiting

Location contact

Tommaso Fossali, MD

CONTACT

+393282194697

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • scheduled for laparoscopic abdominal surgery
  • informed consent signed

Exclusion criteria

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

Treatment and study plan

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

Device

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.

Primary outcomes

  1. 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

Study contacts

Contact information is provided by the study sponsor or research team.

Luigi Guglielmetti, MD

CONTACT

Tommaso Fossali

CONTACT

[email protected]

+393282194697

Sponsors and collaborators

Lead sponsor

ASST Fatebenefratelli Sacco

Other

Registry information

Official study title

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

Acronym: PEaRL

Important dates

Study start
2026
Primary completion
2026
Study completion
2026
First posted
Dec 17, 2025
Registry last updated
Jun 4, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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