Lung Ultrasound Assessment of Postoperative Atelectasis After Mechanical Ventilation With Minimum Driving Pressure

NCT07186920 | Completed

• 1 other identifier: 22623 / 4.8.2025
• Study Type: interventional
• Target: 70
• Locations: 1 country
• Sites: 1

Brief Summary

Brief summary The goal of this clinical trial is to compare two different types of perioperative mechanical ventilation (MV), specifically Protective Mechanical Ventilation (PMV) and MV with the lowest possible Driving Pressure (ΔP), in relation to the appearance of postoperative lung closing, eg atelectasis, in adult patients who are operated. Atelectasis will be evaluated via lung ultrasound. The main questions it aims to answer are:

• Is MV with lower ΔP better than conventional PMV in keeping lungs more open perioperatively and immediately postoperatively?
• Does MV with lower ΔP decrease hospital stay, Intensive Care Unit (ICU) need and mortality? Researchers will use lung ultrasound to compare MV with the lowest possible Driving Pressure (ΔP) to Protective Mechanical Ventilation (PMV) to see if any of this is more protective than the other concerning lung atelectasis. All participants will receive perioperative MV. Half of them will receive conventional Protective Mechanical Ventilation (PMV). This will include well known generally protective settings for mechanical ventilation of patients, concerning volumes, pressures, respiratory rate, inspiratory gases and ventilation maneuvers. The rest of participants will be ventilated with the lowest possible Driving Pressure (ΔP). This will be similar to PMV in the chosen volumes, respiratory rate, inspiratory gases and ventilation maneuvers. However, the pressure inside lung at the end of expiration, eg Positive End Expiratory Pressure (PEEP), will be not be preset for every patient. Initially, we will perform a maneuver that will quantify each individual's lung characteristics and mechanics. According to this, we will find the exact PEEP that seems to suit each patients lungs most, and use this perioperatively, trying to provide lungs the best conditions every time. After the completion of the operation, all the patients will be screened for atelectasis, via lung ultrasound, using a well established protocol for the quantification of atelectasis. The results will be statistically analyzed trying to find if any of the forementioned strategies of mechanical ventilation surpasses the other concerning atelectasis appearance. Furthermore efficiency of lung oxygen absorption, hospital stay, ICU need and mortality will be noted.

Conditions

Postoperative Atelectasis; Postoperative Pulmonary Atelectasis; Postoperative Pulmonary Complications (PPCs); Lung Ultrasonography Score; Lung Ultrasound

Keywords

Postoperative Atelectasis; Postoperative Pulmonary Atelectasis; Postoperative pulmonary complications (PPCs); Lung ultrasonography score; Lung ultrasound; Atelectasis; Pulmonary atelectasis

Outcome Measures

Primary Outcomes (1)

• Lung Ultrasound Score (LUS)

  12 Position Lung Ultrasound will be performed in Post Anesthesia Care Unit (PACU) within 20 minutes postoperatively. In each position the potential scores will be 0,1,2 and 3. 0 --\> 0-2 B-lines 1. --\> \>2 B-lines or presence of small sublpleural consolidations with normal pleural line. 2. --\> Multiple coalescent B-lines or multiple small sublpleural consolidations with thickened or irregular pleural line. 3. --\> Total air loss or subpleural consolidation with diameter bigger than 1x2cm. The total sum of ultrasound scores of each position is marked as LUS.

  Within 20 minutes in PACU.

Secondary Outcomes (10)

• Rate of Postoperative Respiratory Failure

  Within 30 minutes in PACU

• Rate of NIMV need

  Period of stay in Post Anesthesia Care Unit (PACU). From time of postoperative transfer to PACU until time of discharge from PACU and return to general clinic, an average of 1 hour.

• Hospital Stay

  From day of operation until the end of patient stay inside hospital, because of return to home or due to death.

• ICU need.

  From day of operation until the end of patient stay inside hospital, because of return to home or due to death.

• ICU stay

  From day of operation until the end of patient stay inside hospital, because of return to home or due to death.

Study Arms (2)

Lung Protective Ventilation

OTHER

CONVENTIONAL LUNG PROTECTIVE VENTILATION This group is mechanically ventilated with Invasive Mechanical Ventilation with PEEP 8 cm H20 Tidal Volume (VT) 8 ml/kg Ideal Body Weight (IBW) Respiratory Rate (RR) --\> PaCO2 = 35-45 mmHg Inspired Oxygen Fraction (FiO2) 0.4 - 0.5 --\> Pulse Saturation Oxygen (SpO2) \> 93% Recruitment Maneuver (as described) every hour

Procedure: Lung Protective Ventilation

Minimum Driving Pressure

ACTIVE COMPARATOR

This group is mechanically ventilated with Invasive Mechanical Ventilation with PEEP; Initially 8 cm H20, titrated at level with Minimum Driving Pressure after first recruitment - titration maneuver followed by new recruitment maneuver VT 8 ml/kg IBW RR --\> PaCO2 = 35-45 mmHg FiO2 0.4 - 0.5 --\> SpO2 \> 93% Recruitment Maneuver (as described) every hour

Procedure: PEEP titration for Minimum Driving Pressure

Interventions

PEEP titration for Minimum Driving Pressure PROCEDURE

This group is mechanically ventilated with Invasive Mechanical Ventilation with Volume Control Ventilation mode with PEEP Initially 8 cm H2O. Afterwards, the lungs are recruited with the aforementioned maneuver. During subsequent derecruitment, PEEP is decreased by 2 cm H20 and compliance is noted in each stage. The goal is to find PEEP with maximum compliance (Cmax). A new recruitment maneuver follows and during derecruitment PEEP is set at the optimum value that was previously defined. VT 8 ml/kg IBW RR --\> PaCO2 = 35-45 mmHg FiO2 0.4 - 0.5 --\> SpO2 \> 93% Recruitment Maneuver (as described) every hour

Also known as: Maximum compliance mechanical ventilation, Cmax Mechanical Ventilation

Minimum Driving Pressure

Lung Protective Ventilation PROCEDURE

This group is mechanically ventilated with Invasive Mechanical Ventilation with Volume Control Ventilation mode with PEEP 8 cm H2O. VT 8 ml/kg IBW RR --\> PaCO2 = 35-45 mmHg FiO2 0.4 - 0.5 --\> SpO2 \> 93% Recruitment Maneuvers (as described) every hour

Lung Protective Ventilation

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• \>17 years old
• Surgery with general anesthesia \& invasive mechanical ventilation
• ASA score I-III

You may not qualify if:

• \<18 years old
• Preoperative ARISCAT score estimation \<26
• Women during pregnancy or just given birth
• Other type of anesthesia (Not general)
• Contraindication of administration of neuromuscular blockade agents.
• Contraindication of cease of spontaneous ventilation.
• Mechanical ventilation without endotracheal intubation.
• Severe heart failure / History of ischemic heart disease.
• Moderate or severe chronic obstructive lung disease or interstitial lung disease.
• History of operation in heart, lung or diaphragm.
• Presence of new active pathology in respiratory system at the beginning of surgery (infection / trauma / anatomic disorder).
• Severe intraoperative respiratory complication (laryngospasm / bronchospasm / anaphylaxis).
• Immediate postoperative need for continuation of IMV.
• Patient denial of participation in the trial.

Sponsors & Collaborators

• University General Hospital of Patras: lead

Study Sites (1)

University Hospital of Patras

Pátrai, 26504, Greece

Location

MeSH Terms

Conditions

Pulmonary Atelectasis

Condition Hierarchy (Ancestors)

Lung Diseases; Respiratory Tract Diseases

Study Officials

• Diamanto Aretha, A. Professor

  University of Patras

  STUDY CHAIR

• Nektaria Xirouchaki, Consultant

  University of Crete

  STUDY DIRECTOR

• Eumorfia Kondili, Professor

  University of Crete

  STUDY DIRECTOR

• Antonios Kostouros, Resident

  University of Patras

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Anesthesiology Resident, Antonios Kostouros

Study Record Dates

• First Submitted: August 20, 2025
• First Posted: September 22, 2025
• Study Start: October 6, 2025
• Primary Completion: December 31, 2025
• Study Completion: January 15, 2026
• Last Updated: February 11, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will share

Locations

GR (1)