Pneumoperitoneum Pressure and Lung Ultrasound Atelectasis

May 26, 2026 updated by: Engin Çetin

Effects of Different Pneumoperitoneum Pressures on Perioperative Atelectasis Assessed by Lung Ultrasound in Laparoscopic Cholecystectomy: A Prospective Randomized Single-Blind Controlled Trial

Elective laparoscopic cholecystectomy may lead to perioperative atelectasis due to pneumoperitoneum-related diaphragmatic elevation and impaired respiratory mechanics. Lung ultrasound (LUS) provides a noninvasive bedside method for evaluating perioperative aeration loss. This prospective randomized controlled study aims to compare the effects of low-pressure (10 mmHg) and standard-pressure (14 mmHg) pneumoperitoneum on perioperative atelectasis assessed by LUS in patients undergoing laparoscopic cholecystectomy under general anesthesia. Changes in LUS scores, respiratory mechanics, oxygenation, and postoperative clinical outcomes will also be evaluated.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Elective laparoscopic cholecystectomy may cause perioperative atelectasis due to pneumoperitoneum-related impairment of respiratory mechanics. Lung ultrasound (LUS) is a noninvasive bedside tool that can evaluate perioperative lung aeration loss and atelectasis.

This prospective randomized single-blind controlled trial aims to compare the effects of low-pressure (10 mmHg) and standard-pressure (14 mmHg) pneumoperitoneum on perioperative atelectasis assessed by LUS in patients undergoing elective laparoscopic cholecystectomy under general anesthesia. Patients will be randomized into two groups according to pneumoperitoneum pressure level.

LUS assessments will be performed before pneumoperitoneum, at the end of surgery before extubation, and at the postoperative first hour. The primary outcome will be the change in LUS score from baseline to the end of surgery. Secondary outcomes will include respiratory mechanics, oxygenation parameters, postoperative oxygen requirement, postoperative pain, nausea-vomiting, and recovery outcomes.

Study Type

Interventional

Enrollment (Estimated)

112

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 Locations

  • Turkey (Türkiye)
    • Kocaeli
      • İzmit, Kocaeli, Turkey (Türkiye), 41200
        • University of Health Sciences Kocaeli City Hospital
        • Contact:

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:

  • Patients aged between 18 and 65 years
  • ASA physical status I-II
  • Scheduled for elective laparoscopic cholecystectomy under general anesthesia
  • Body mass index (BMI) <30 kg/m²
  • Ability to provide written informed consent

Exclusion Criteria:

  • Chronic pulmonary disease
  • Recent respiratory tract infection
  • Thoracic deformity or previous thoracic surgery
  • Preoperative pulmonary pathology
  • Morbid obesity
  • Pregnancy
  • Emergency surgery
  • Conversion to open surgery
  • Requirement for protocol-violating pneumoperitoneum pressure modification
  • Refusal to participate in the study

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: Diagnostic
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: 10 mmHg Pneumoperitoneum
Patients in this group will undergo laparoscopic cholecystectomy with pneumoperitoneum maintained at 10 mmHg.
Diagnostic test: 10 mmHg Pneumoperitoneum
Laparoscopic cholecystectomy will be performed with intra-abdominal pressure maintained at 10 mmHg during insufflation. Standard anesthesia and surgical protocols will be followed.
Active Comparator: 14 mmHg Pneumoperitoneum
Patients in this group will undergo laparoscopic cholecystectomy with pneumoperitoneum maintained at 14 mmHg.
Diagnostic test: 14 mmHg Pneumoperitoneum
Laparoscopic cholecystectomy will be performed with intra-abdominal pressure maintained at 14 mmHg during insufflation. Standard anesthesia and surgical protocols will be followed.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Total Lung Ultrasound Score (LUS) Change From Baseline
Time Frame: T0: After anesthesia induction and before pneumoperitoneum initiation (baseline); T1: At the end of surgery before extubation; T2: 1 hour after arrival in the post-anesthesia care unit (PACU)
Perioperative lung aeration loss and atelectasis will be assessed using the Lung Ultrasound Score (LUS) during laparoscopic cholecystectomy performed under two different pneumoperitoneum pressures (10 mmHg vs 14 mmHg). Lung ultrasonography will be performed on predefined anterior and lateral chest wall regions bilaterally. Each lung region will be scored from 0 to 3 according to the degree of aeration loss, and the total LUS will range from 0 to 24. Higher scores indicate greater loss of lung aeration and more severe atelectasis.
T0: After anesthesia induction and before pneumoperitoneum initiation (baseline); T1: At the end of surgery before extubation; T2: 1 hour after arrival in the post-anesthesia care unit (PACU)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Peak Airway Pressure (cmH₂O)
Time Frame: T0: Before pneumoperitoneum initiation (baseline); T1: 30 minutes after pneumoperitoneum initiation; T2: At the end of surgery before pneumoperitoneum desufflation
Intraoperative peak airway pressure (cmH₂O) during laparoscopic cholecystectomy will be measured using the anesthesia ventilator and compared between the low-pressure pneumoperitoneum (10 mmHg) and standard-pressure pneumoperitoneum (14 mmHg) groups.
T0: Before pneumoperitoneum initiation (baseline); T1: 30 minutes after pneumoperitoneum initiation; T2: At the end of surgery before pneumoperitoneum desufflation
Dynamic Lung Compliance (mL/cmH₂O) Measured by Mechanical Ventilator
Time Frame: Baseline (before pneumoperitoneum) and 5, 15, 30, and 45 minutes after pneumoperitoneum initiation
Intraoperative dynamic lung compliance (mL/cmH₂O), measured using the anesthesia ventilator, will be compared between low-pressure pneumoperitoneum (10 mmHg) and standard-pressure pneumoperitoneum (14 mmHg) groups during laparoscopic cholecystectomy.
Baseline (before pneumoperitoneum) and 5, 15, 30, and 45 minutes after pneumoperitoneum initiation

Collaborators and Investigators

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

Sponsor

Engin Çetin

Investigators

  • Principal Investigator: Engin Çetin, Kocaeli City Hospital

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)

June 1, 2026

Primary Completion (Estimated)

September 1, 2026

Study Completion (Estimated)

September 1, 2026

Study Registration Dates

First Submitted

May 17, 2026

First Submitted That Met QC Criteria

May 21, 2026

First Posted (Actual)

May 27, 2026

Study Record Updates

Last Update Posted (Actual)

May 28, 2026

Last Update Submitted That Met QC Criteria

May 26, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • KSH-ANREA-EC-06

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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