Lung Ultrasound Evaluation of Individualized Versus Standard PEEP on Postoperative Atelectasis in Gynecological Laparoscopy

Evaluation of the Effect of Driving Pressure-Guided Individualized PEEP Titration Versus Standard PEEP on Early and Late Postoperative Atelectasis Development Using Lung Ultrasonography in Gynecological Laparoscopic Surgeries

The purpose of this study is to compare two different airway pressure (PEEP) strategies during gynecological laparoscopic surgery to see which one better prevents lung collapse (atelectasis). We will compare a 'standard' fixed pressure with a 'personalized' pressure adjusted according to the patient's own lung mechanics (driving pressure). We will use lung ultrasound to check the lungs before surgery, 1 hour after surgery, and 24 hours after surgery to evaluate the results.

Study Overview

• Status: Active, not recruiting
• Conditions: Atelectasis

Detailed Description

In this prospective observational study, we investigate the impact of PEEP strategies on lung collapse (atelectasis) in patients undergoing gynecological laparoscopy. The Standard Group receives a routine clinical application of 5 cmH2O PEEP. The Individualized Group undergoes a PEEP titration protocol where PEEP starts at 20 cmH2O and is adjusted to reach the optimal level based on the lowest driving pressure. To measure the results, a 12-zone Lung Ultrasonography (LUS) scoring system (0-3 points per zone) is utilized. Evaluations are conducted preoperatively (baseline), 1 hour postoperatively (early phase), and 24 hours postoperatively (late phase) to track the development and resolution of atelectasis.

• Study Type: Observational
• Enrollment (Estimated): 72

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Ankara, Turkey (Türkiye)
    • Etlik City Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study population consists of adult female patients (aged 18 to 65 years) with an American Society of Anesthesiologists (ASA) physical status of I, II, or III, who are scheduled for elective gynecological laparoscopic surgeries (e.g., hysterectomy, myomectomy, sacrocolpopexy) under general anesthesia with endotracheal intubation at Ankara Etlik City Hospital.

Description

Inclusion Criteria:

• Female patients aged between 18 and 65 years.
• American Society of Anesthesiologists (ASA) physical status I, II, or III.
• Scheduled for elective laparoscopic gynecological surgery (e.g., hysterectomy, myomectomy, sacrocolpopexy).
• Planned to undergo general anesthesia with endotracheal intubation.
• Expected surgery duration of 2 hours or more.
• Body Mass Index (BMI) ≤ 35 kg/m².

Exclusion Criteria:

• History of moderate-to-severe Chronic Obstructive Pulmonary Disease (COPD), clinically significant interstitial lung disease, or severe restrictive lung disease.
• New York Heart Association (NYHA) class III-IV heart failure, Ejection Fraction (EF) < 35%, or severe valvular disease.
• Advanced arrhythmia or hemodynamic instability (requiring high-dose vasopressor support).
• History of respiratory failure requiring mechanical ventilation within the past 4 weeks.
• Clinically or radiologically confirmed lower respiratory tract infection (e.g., pneumonia) within the past 1 month.
• Presence of thoracic deformity, large surgical dressings, severe subcutaneous emphysema, or any condition that hinders lung ultrasound evaluation.
• Pre-existing significant atelectasis or lung consolidation (defined as a score of 3 for consolidation or ≥2 zones with a score of ≥2 on preoperative LUS).
• Expected inability to perform the 24-hour postoperative ultrasound measurement (e.g., due to early discharge).

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Grup 1: Standard PEEP Group; Patients undergoing gynecological laparoscopic surgery who are observed receiving a routine, fixed Positive End-Expiratory Pressure (PEEP) of 5 cmH2O during the intraoperative period.
Grup 2: Individualized PEEP Group; Following an initial lung recruitment maneuver, patients undergo individualized PEEP titration. PEEP is initially set to 20 cmH2O and then sequentially decreased in steps of 2 cmH2O to identify the optimal level associated with the lowest driving pressure.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Lung Ultrasonography (LUS) Score	Atelectasis severity is assessed using a 12-zone Lung Ultrasonography (LUS) scoring system. Each zone is scored from 0 to 3 (0=normal aeration, 3=consolidation). The total score ranges from 0 to 36. Higher scores indicate worse lung aeration and more severe atelectasis.	Preoperatively (baseline), 1 hour postoperatively, and 24 hours postoperatively.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Correlation Between Intraoperative Ventilation Parameters and Early Postoperative LUS Scores	Evaluation of the relationship between intraoperative respiratory parameters (Peak Airway Pressure [Ppeak], Plateau Pressure [Pplat], and Compliance) and early postoperative lung aeration assessed by Lung Ultrasonography (LUS) in the Post-Anesthesia Care Unit (PACU).	From the start of anesthesia until 1 hour postoperatively.
Correlation Between Intraoperative Ventilation Parameters and Postoperative Oxygenation	Evaluation of the relationship between intraoperative respiratory parameters (Ppeak, Pplat, and Compliance) and postoperative peripheral oxygen saturation (SpO₂) in the PACU.	From the start of anesthesia until 1 hour postoperatively.
Correlation Between Intraoperative Ventilation Parameters and Early Postoperative Pulmonary Complications	Evaluation of whether intraoperative respiratory parameters (Ppeak, Pplat, and Compliance) are associated with the development of clinical pulmonary complications within the first 24 hours.	From the start of anesthesia up to 24 hours postoperatively.

Collaborators and Investigators

• Sponsor: Ankara Etlik City Hospital
• Investigators: Study Director: ILKAY BARAN AKKUS, MD, Associate Professor, Ankara Etlik City Hospital

Study record dates

Study Major Dates

• Study Start (Actual): February 18, 2026
• Primary Completion (Estimated): December 30, 2026
• Study Completion (Estimated): December 31, 2026

Study Registration Dates

• First Submitted: May 16, 2026
• First Submitted That Met QC Criteria: May 16, 2026
• First Posted (Actual): May 22, 2026

Study Record Updates

• Last Update Posted (Actual): May 22, 2026
• Last Update Submitted That Met QC Criteria: May 16, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Laparoscopy; Lung Ultrasound; Positive End-Expiratory Pressure; Driving Pressure; Gynecologic Surgical Procedures
• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Lung Diseases; Pulmonary Atelectasis
• Other Study ID Numbers: AEŞH-BADEK2-2026-188

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