Pulmonary Atelectasis, PostoperativeVENTI-PRONENCT07680881
Ventilation Mode and Atelectasis After Prone-Position Surgery: A Lung Ultrasound Study
An observational study of Pulmonary Atelectasis, Postoperative and Postoperative Pulmonary Complications, run by Prof. Dr. Cemil Tascıoglu Education and Research Hospital Organization at 1 site in Turkey (Türkiye).
Trial summary
This prospective single-centre observational study compared two intraoperative mechanical ventilation modes, volume-controlled ventilation (VCV) and VCV with AutoFlow/AF, in adults undergoing elective surgery in the prone position. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Pulmonary Atelectasis, Postoperative, Postoperative Pulmonary Complications
- How many people
- 90 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Mar 2024to 30 Oct 2024
- Phase
- Observational
- 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 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Adults aged 18 to 65 years with American Society of Anesthesiologists physical status I or II and a body mass index below 35 kg/m2, scheduled for elective surgery in the prone position at a single tertiary care hospital. Patients were grouped according to the intraoperative ventilation mode selected by the attending anaesthesiologist (volume-controlled ventilation or volume-controlled ventilation with Autoflow).
Who may be able to join
- Consented adults aged 18 to 65 years American Society of Anesthesiologists (ASA) physical status I or II Body mass index below 35 kg/m2 Scheduled for elective surgery in the prone position Oriented and cooperative
Who cannot join
- No consent Pre-existing pulmonary disease Any perioperative lung pathology Inability to complete postoperative lung ultrasound assessment
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Cemil Tasciogu Research and Training Hospital
Istanbul, Sisli
About this study
Official title: Volume-Controlled Versus VCV With AutoFlow Assessed by a Modified Lung Ultrasound Score and the Alveolar-Arterial Oxygen Gradient in Adults Undergoing Prone-Position Surgery: A Prospective Single-Centre Observational Study
This prospective single-centre observational study compared two intraoperative mechanical ventilation modes, volume-controlled ventilation (VCV) and VCV with AutoFlow/AF, in adults undergoing elective surgery in the prone position. The ventilation mode was selected by the attending anaesthesiologist as part of routine clinical care; the investigators did not assign it. Perioperative atelectasis was assessed using a modified bilateral 12-zone lung ultrasound score obtained before induction of anaesthesia and after extubation, and oxygenation was assessed using the alveolar-arterial oxygen gradient calculated from an intraoperative arterial blood gas sample. The study also examined whether the effect of ventilation mode on atelectasis differed according to obesity.
Read the detailed description
Ninety adults (American Society of Anesthesiologists physical status I-II, body mass index below 35 kg/m2, aged 18 to 65 years) scheduled for elective prone-position surgery were grouped by the ventilation strategy chosen by the attending anaesthesiologist: VCV (n=45) or VCV-AF (n=45). Both groups received a tidal volume of 6 to 8 mL/kg and median positive end-expiratory pressure of 5 cmH2O, delivered with a Draeger Perseus A500 anaesthesia workstation. A modified lung ultrasound score was obtained in the supine position using a 2 to 5 MHz convex probe before induction and at least 30 minutes after extubation, with each hemithorax divided into anterior, lateral and posterior regions and each region scored for loss of aeration. The alveolar-arterial oxygen gradient was calculated from an arterial blood gas sample taken 15 minutes after prone positioning. Patients were stratified by body mass index (below 30 versus 30 kg/m2 or above).
The primary comparison was the postoperative lung ultrasound score between the two ventilation modes. Pre-specified analyses included adjustment for the baseline lung ultrasound score using analysis of covariance and a formal ventilation-mode by obesity interaction test. The correlation between the lung ultrasound score and the alveolar-arterial oxygen gradient was also assessed. Of 97 patients initially enrolled, seven were excluded because postoperative lung ultrasound data could not be completed owing to unavailability of the ultrasound device or operator, leaving 90 patients with complete data for analysis.
- Keywords
- Lung ultrasound, Atelectasis, Prone position, Mechanical ventilation, Alveolar-arterial oxygen gradient
- Medical subject headings
- Pulmonary Atelectasis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| VCV | Patients managed intraoperatively with volume-controlled ventilation, as chosen by the attending anaesthesiologist. | |
| VCV-AF | Patients managed intraoperatively with Volume-Controlled Ventilation with AutoFlow ventilation, as chosen by the attending anaesthesiologist. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Postoperative modified lung ultrasound score
Modified bilateral 12-zone lung ultrasound score assessed after surgery and compared between ventilation modes. Each hemithorax was divided into anterior, lateral and posterior regions, and each region was scored for loss of aeration, with a higher total score indicating greater atelectasis.
Measured: At least 30 minutes after extubation
Secondary outcomes (2)
Alveolar-arterial oxygen gradient
Alveolar-arterial oxygen gradient calculated from an intraoperative arterial blood gas sample, compared between ventilation modes.
Measured: 15 minutes after prone positioning
Ventilation-mode by obesity interaction on postoperative lung ultrasound score
Difference in the effect of ventilation mode on the postoperative lung ultrasound score between non-obese patients (body mass index below 30 kg/m2) and obese patients (body mass index 30 kg/m2 or above), tested as a formal interaction.
Measured: At least 30 minutes after extubation
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Jul 2026
- Study start1 Mar 2024
- Primary completion30 Oct 2024
- Study completion30 Oct 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Pulmonary Atelectasis, PostoperativeStudies 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 90 participants (actual)
Sponsor and investigators
- Lead sponsor
- Prof. Dr. Cemil Tascıoglu Education and Research Hospital Organization
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Taylan Kırdan, Prof. Dr. Cemil Tascıoglu Education and Research Hospital Organization
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07680881
- Sponsor's protocol ID
- CTH-PRONE-LUS-2024
- Acronym
- VENTI-PRONE
- Status last verified
- Jun 2026
- First submitted
- 26 Jun 2026
- Last updated
- 29 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 29 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Volume-Controlled Versus VCV With AutoFlow Assessed by a Modified Lung Ultrasound Score and the Alveolar-Arterial Oxygen Gradient in Adults Undergoing Prone-Position Surgery: A Prospective Single-Centre Observational Study
- ClinicalTrials.gov ID
- NCT07680881
- Acronym / sponsor ID
- VENTI-PRONE / CTH-PRONE-LUS-2024
- Keywords
- Lung ultrasound, Atelectasis, Prone position, Mechanical ventilation, Alveolar-arterial oxygen gradient
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 90 participants (actual)
- Lead sponsor
- Prof. Dr. Cemil Tascıoglu Education and Research Hospital OrganizationUniversity, hospital or other
- Study start
- 1 Mar 2024 (actual)
- Primary completion
- 30 Oct 2024 (actual)
- Study completion
- 30 Oct 2024 (actual)
- First posted
- 2 Jul 2026 (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.
This prospective single-centre observational study compared two intraoperative mechanical ventilation modes, volume-controlled ventilation (VCV) and VCV with AutoFlow/AF, in adults undergoing elective surgery in the prone position. The ventilation mode was selected by the attending anaesthesiologist as part of routine clinical care; the investigators did not assign it. Perioperative atelectasis was assessed using a modified bilateral 12-zone lung ultrasound score obtained before induction of anaesthesia and after extubation, and oxygenation was assessed using the alveolar-arterial oxygen gradient calculated from an intraoperative arterial blood gas sample. The study also examined whether the effect of ventilation mode on atelectasis differed according to obesity.
Detailed description
Ninety adults (American Society of Anesthesiologists physical status I-II, body mass index below 35 kg/m2, aged 18 to 65 years) scheduled for elective prone-position surgery were grouped by the ventilation strategy chosen by the attending anaesthesiologist: VCV (n=45) or VCV-AF (n=45). Both groups received a tidal volume of 6 to 8 mL/kg and median positive end-expiratory pressure of 5 cmH2O, delivered with a Draeger Perseus A500 anaesthesia workstation. A modified lung ultrasound score was obtained in the supine position using a 2 to 5 MHz convex probe before induction and at least 30 minutes after extubation, with each hemithorax divided into anterior, lateral and posterior regions and each region scored for loss of aeration. The alveolar-arterial oxygen gradient was calculated from an arterial blood gas sample taken 15 minutes after prone positioning. Patients were stratified by body mass index (below 30 versus 30 kg/m2 or above).
The primary comparison was the postoperative lung ultrasound score between the two ventilation modes. Pre-specified analyses included adjustment for the baseline lung ultrasound score using analysis of covariance and a formal ventilation-mode by obesity interaction test. The correlation between the lung ultrasound score and the alveolar-arterial oxygen gradient was also assessed. Of 97 patients initially enrolled, seven were excluded because postoperative lung ultrasound data could not be completed owing to unavailability of the ultrasound device or operator, leaving 90 patients with complete data for analysis.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| VCV | – | –Patients managed intraoperatively with volume-controlled ventilation, as chosen by the attending anaesthesiologist. |
| VCV-AF | – | –Patients managed intraoperatively with Volume-Controlled Ventilation with AutoFlow ventilation, as chosen by the attending anaesthesiologist. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Adults aged 18 to 65 years with American Society of Anesthesiologists physical status I or II and a body mass index below 35 kg/m2, scheduled for elective surgery in the prone position at a single tertiary care hospital. Patients were grouped according to the intraoperative ventilation mode selected by the attending anaesthesiologist (volume-controlled ventilation or volume-controlled ventilation with Autoflow).
Key inclusion criteria (1 listed)
- Consented adults aged 18 to 65 years American Society of Anesthesiologists (ASA) physical status I or II Body mass index below 35 kg/m2 Scheduled for elective surgery in the prone position Oriented and cooperative
Key exclusion criteria (1 listed)
- No consent Pre-existing pulmonary disease Any perioperative lung pathology Inability to complete postoperative lung ultrasound assessment
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Postoperative modified lung ultrasound score
Time frame: At least 30 minutes after extubation
Modified bilateral 12-zone lung ultrasound score assessed after surgery and compared between ventilation modes. Each hemithorax was divided into anterior, lateral and posterior regions, and each region was scored for loss of aeration, with a higher total score indicating greater atelectasis.
2 secondary outcomes
Alveolar-arterial oxygen gradient
Time frame: 15 minutes after prone positioning
Ventilation-mode by obesity interaction on postoperative lung ultrasound score
Time frame: At least 30 minutes after extubation
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 29 Jul 2026.
- Individual participant dataSharing planned: No
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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.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Pulmonary Atelectasis, Postoperative and Postoperative Pulmonary Complications, run by Prof. Dr. Cemil Tascıoglu Education and Research Hospital Organization at 1 site in Turkey (Türkiye).
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 1 inclusion and 1 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 29 Jul 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 Turkey (Türkiye). 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?
Postoperative modified lung ultrasound score (time frame: At least 30 minutes after extubation). 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 29 Jul 2026.