Postoperative AtelectasisNCT07186920
Lung Ultrasound Assessment of Postoperative Atelectasis After Mechanical Ventilation With Minimum Driving Pressure
A study testing PEEP titration for Minimum Driving Pressure and Lung Protective Ventilation in people with Postoperative Atelectasis and Postoperative Pulmonary Atelectasis, run by University General Hospital of Patras at 1 site in Greece.
Trial 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… Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Postoperative Atelectasis, Postoperative Pulmonary Atelectasis, Postoperative Pulmonary Complications (PPCs)
- What is being tested?
- PEEP titration for Minimum Driving Pressure and Lung Protective Ventilation
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 70 participants
- Where
- 1 siteGreece
- Study dates
- 6 Oct 2025to 15 Jan 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- >17 years old
- Surgery with general anesthesia \& invasive mechanical ventilation
- ASA score I-III
Who cannot join
- <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.
Show all 14Show fewer
- 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.
Trial locations and contacts
1 site in 1 country.
About this study
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:
Read more
- 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
- Being tested
- PEEP titration for Minimum Driving Pressure, Lung Protective Ventilation
- Keywords
- Postoperative Atelectasis, Postoperative Pulmonary Atelectasis, Postoperative pulmonary complications (PPCs), Lung ultrasonography score, Lung ultrasound, Atelectasis, Pulmonary atelectasis
- Medical subject headings
- Pulmonary Atelectasis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PEEP titration for Minimum Driving PressureProcedure or surgery
Also called Maximum compliance mechanical ventilation, Cmax Mechanical Ventilation
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
Lung Protective VentilationProcedure or surgery
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
| Study group | Role | What they receive |
|---|---|---|
| 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 Receives: 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 Receives: Procedure: PEEP titration for Minimum Driving Pressure |
What is being measured
The primary outcome is the main question the study is designed to answer.
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
- --> >2 B-lines or presence of small sublpleural consolidations with normal pleural line.
- --> Multiple coalescent B-lines or multiple small sublpleural consolidations with thickened or irregular pleural line.
- --> Total air loss or subpleural consolidation with diameter bigger than 1x2cm. The total sum of ultrasound scores of each position is marked as LUS.
Measured: Within 20 minutes in PACU.
Secondary outcomes (10)
Rate of Postoperative Respiratory Failure
Postoperative Respiratory Failure based on Arterial Blood Gases in PACU (type I and/or II) Type I --> Arterial Oxygen Partial Pressure / Arterial Oxygen Saturation (P/F) ratio <300 Type II --> PaCO2 > 45mmHg
Measured: Within 30 minutes in PACU
Rate of NIMV need
Potential need for NIMV in PACU due to Respiratory Failure.
CPAP / BIPAP / High-Flow Nasal Canula
Measured: 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
Total hospital stay days from day of operation until hospital discharge.
Measured: From day of operation until the end of patient stay inside hospital, because of return to home or due to death.
ICU need.
Potential Need for ICU admission.
Measured: From day of operation until the end of patient stay inside hospital, because of return to home or due to death.
ICU stay
In case of ICU need, total days of ICU stay.
Measured: From day of operation until the end of patient stay inside hospital, because of return to home or due to death.
28 Day mortality
Incidence of death in 28 days in each group.
Measured: From day of operation until up to 28 days.
Mechanical Power (MP)
- To calculate MP, the following must be recorded: RR, Peak Airway Pressure (Ppeak), Plateau Pressure (Pplat), and PEEP. The simplified equation will be used; MP = 0.098 × RR × [Ppeak - (Plat-PEEP)/2]
Measured: From the moment of beginning of operation until the moment of the end of operation and mechanical ventilation
Volume-normalized Mechanical Power (MPcrs)
MPcrs = MP/Respiratory System Compliance (Crs)
Measured: From the moment of beginning of operation until the moment of the end of operation and mechanical ventilation
Elastic Power (EP)
To calculate EP, the following must be recorded: RR, VT, Pplat, and PEEP. The following equation will be used:
EP = 0.098 × RR × VT × [(Plat+PEEP)/2]
Measured: From the moment of beginning of operation until the moment of the end of operation and mechanical ventilation
Volume-normalized Elastic Power (EPcrs)
EPcrs = EP/Crs
Measured: From the moment of beginning of operation until the moment of the end of operation and mechanical ventilation
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Sep 2025
- Study start6 Oct 2025
- Primary completion31 Dec 2025
- Study completion15 Jan 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Postoperative AtelectasisStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 70 participants (actual)
Sponsor and investigators
- Lead sponsor
- University General Hospital of Patras
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Antonios Kostouros, University General Hospital of Patras
- Investigators
- Diamanto Aretha, A. Professor, Study chair, University of PatrasNektaria Xirouchaki, Consultant, Study director, University of CreteEumorfia Kondili, Professor, Study director, University of CreteAntonios Kostouros, Resident, Principal investigator, University of Patras
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07186920
- Sponsor's protocol ID
- 22623 / 4.8.2025
- Status last verified
- Feb 2026
- First submitted
- 20 Aug 2025
- Last updated
- 11 Feb 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 11 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Lung Ultrasound Assessment of Postoperative Atelectasis After Mechanical Ventilation With Minimum Driving Pressure
- ClinicalTrials.gov ID
- NCT07186920
- Acronym / sponsor ID
- 22623 / 4.8.2025
- 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
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 70 participants (actual)
- Lead sponsor
- University General Hospital of PatrasUniversity, hospital or other
- Study start
- 6 Oct 2025 (actual)
- Primary completion
- 31 Dec 2025 (actual)
- Study completion
- 15 Jan 2026 (actual)
- First posted
- 22 Sep 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Lung Protective Ventilation | Other | Procedure: Lung Protective VentilationCONVENTIONAL 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 |
| Minimum Driving Pressure | Active comparator | Procedure: PEEP titration for Minimum Driving PressureThis 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 |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- >17 years old
- Surgery with general anesthesia \& invasive mechanical ventilation
- ASA score I-III
Key exclusion criteria (14 listed)
- <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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PEEP titration for Minimum Driving PressureAlso: Maximum compliance mechanical ventilation, Cmax Mechanical VentilationThis 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 | Procedure or surgery | Minimum Driving Pressure |
| Lung Protective VentilationThis 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 | Procedure or surgery | Lung Protective Ventilation |
Primary outcome
Lung Ultrasound Score (LUS)
Time frame: Within 20 minutes in PACU.
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.
10 secondary outcomes
Rate of Postoperative Respiratory Failure
Time frame: Within 30 minutes in PACU
Rate of NIMV need
Time frame: 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
Time frame: From day of operation until the end of patient stay inside hospital, because of return to home or due to death.
ICU need.
Time frame: From day of operation until the end of patient stay inside hospital, because of return to home or due to death.
ICU stay
Time frame: From day of operation until the end of patient stay inside hospital, because of return to home or due to death.
28 Day mortality
Time frame: From day of operation until up to 28 days.
Mechanical Power (MP)
Time frame: From the moment of beginning of operation until the moment of the end of operation and mechanical ventilation
Volume-normalized Mechanical Power (MPcrs)
Time frame: From the moment of beginning of operation until the moment of the end of operation and mechanical ventilation
Elastic Power (EP)
Time frame: From the moment of beginning of operation until the moment of the end of operation and mechanical ventilation
Volume-normalized Elastic Power (EPcrs)
Time frame: From the moment of beginning of operation until the moment of the end of operation and mechanical ventilation
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Feb 2026.
- Individual participant dataSharing planned: Yes
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Diamanto Aretha, A. Professor study chair
University of Patras
Nektaria Xirouchaki, Consultant study director
University of Crete
Eumorfia Kondili, Professor study director
University of Crete
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing PEEP titration for Minimum Driving Pressure and Lung Protective Ventilation in people with Postoperative Atelectasis and Postoperative Pulmonary Atelectasis, run by University General Hospital of Patras at 1 site in Greece.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 11 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Greece. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Lung Ultrasound Score (LUS) (time frame: Within 20 minutes in PACU.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Feb 2026.