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NCT Number: NCT07609615

Pneumoperitoneum Pressure and Lung Ultrasound Atelectasis

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.

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Key information

Conditions

Atelectasis Digestive System Diseases Lung Diseases Perioperative Complication Peritoneal Diseases Pneumoperitoneum Pulmonary Atelectasis Respiratory Tract Diseases

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Health Sciences Kocaeli City Hospital

İzmit, Kocaeli, 41200, Turkey (Türkiye)

Location status: Recruiting

Location contact

Engin Çetin, M.D

CONTACT

[email protected]

05321206004 ext. op

About this study

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.

Who can participate

Healthy volunteers accepted: No

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

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

Treatment and study plan

10 mmHg Pneumoperitoneum

Diagnostic Test

Laparoscopic cholecystectomy will be performed with intra-abdominal pressure maintained at 10 mmHg during insufflation. Standard anesthesia and surgical protocols will be followed.

14 mmHg Pneumoperitoneum

Diagnostic Test

Laparoscopic cholecystectomy will be performed with intra-abdominal pressure maintained at 14 mmHg during insufflation. Standard anesthesia and surgical protocols will be followed.

Primary outcomes

  1. 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.

Secondary outcomes

  1. 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.

  2. 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.

Study contacts

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

Engin Cetin

CONTACT

[email protected]

05321206004

Engin Çetin

CONTACT

[email protected]

05321206004

Sponsors and collaborators

Lead sponsor

Engin Çetin

Other Gov

Registry information

Official study title

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

Important dates

Study start
2026
Primary completion
2026
Study completion
2026
First posted
May 27, 2026
Registry last updated
Jun 23, 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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