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

NCT ID: NCT07186920

Last Updated: 2026-02-11

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 70 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-10-06
• Study Completion Date: 2026-01-15

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

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: SINGLE

Study Groups

Lung Protective Ventilation

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

Group Type: OTHER

Lung Protective Ventilation

Intervention Type: 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

Minimum Driving Pressure

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

Group Type: ACTIVE_COMPARATOR

PEEP titration for Minimum Driving Pressure

Intervention Type: 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

Interventions

PEEP titration for Minimum Driving Pressure

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

Intervention Type: PROCEDURE

Lung Protective Ventilation

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

Intervention Type: PROCEDURE

Other Intervention Names

Maximum compliance mechanical ventilation; Cmax Mechanical Ventilation

Eligibility Criteria

Inclusion Criteria

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

Exclusion Criteria

• <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.

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University General Hospital of Patras

OTHER

Sponsor Role: lead

Responsible Party

Antonios Kostouros

Anesthesiology Resident, Antonios Kostouros

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Diamanto Aretha, A. Professor

Role: STUDY_CHAIR

University of Patras

Nektaria Xirouchaki, Consultant

Role: STUDY_DIRECTOR

University of Crete

Eumorfia Kondili, Professor

Role: STUDY_DIRECTOR

University of Crete

Antonios Kostouros, Resident

Role: PRINCIPAL_INVESTIGATOR

University of Patras

Locations

University Hospital of Patras

Pátrai, , Greece

Countries

Greece

Other Identifiers

22623 / 4.8.2025

Identifier Type: -

Identifier Source: org_study_id