Obesity (Body Mass Index >30 kg/m2)NCT07345650
Dynamic Compliance-Guided Personalized PEEP During Laparoscopic Bariatric Surgery: Effects on Intraoperative Respiratory Parameters
An observational study of Obesity (Body Mass Index >30 kg/m2) and Atelectasis, Postoperative, run by Yeditepe University at 1 site in Turkey (Türkiye).
Trial summary
Atelectasis may be encountered in the patient population aged 18-65 years undergoing elective laparoscopic bariatric surgery under general anesthesia with endotracheal intubation. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Obesity (Body Mass Index >30 kg/m2), Atelectasis, Postoperative, PEEP With Dynamic Compliance
- What is being tested?
- Individualized approach
- Type of treatment
- Medical device
- How many people
- 40 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Dec 2024to 10 Apr 2026
- How long will I take part?
- 6 Months
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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: The study population consisted of adult women and men aged 18 to 65 years who were scheduled for elective laparoscopic bariatric surgery. Eligible participants had an American Society of Anesthesiologists (ASA) physical status of I-III and a body mass index (BMI) greater than 30 kg/m². All participants provided written informed consent prior to enrollment. Patients were excluded if they were younger than 18 years or older than 65 years, were not scheduled for bariatric surgery, had an ASA physical status of IV-V, or a BMI less than 30 kg/m². Additional exclusion criteria included refusal or inability to provide informed consent; a history of chronic obstructive pulmonary disease (COPD) classified as GOLD stage III or IV; severe or uncontrolled bronchial asthma; severe restrictive lung disease; a history of pulmonary metastases or previous thoracic surgery; the requirement for preoperative thoracic drainage; the need for preoperative renal replacement therapy; and congestive heart fail
Who may be able to join
- Adult women and men aged 18 to 65 years Scheduled for elective laparoscopic bariatric surgery American Society of Anesthesiologists (ASA) physical status I-III Body mass index (BMI) > 30 kg/m² Provision of written informed consent
Who cannot join
- Age < 18 years or > 65 years Not scheduled for bariatric surgery ASA physical status IV-V Body mass index (BMI) < 30 kg/m² Refusal or inability to provide inHistory of Chronic Obstructive Pulmonary Disease (GOLD III and IV) History of severe/uncontrolled bronchial asthma Severe restrictive lung disease History of pulmonary metastases History of thoracic surgery Requiring preoperative thoracic drainage Requiring preoperative renal replacement therapy Congestive heart failure (NYHA Class III and IV)
Trial locations and contacts
1 site in 1 country.
About this study
Atelectasis may be encountered in the patient population aged 18-65 years undergoing elective laparoscopic bariatric surgery under general anesthesia with endotracheal intubation. The aim of this study is to compare oxygenation, postoperative atelectasis, and postoperative respiratory complications between the fixed PEEP application (SP Group) and personalized PEEP application (KP Group). In the SP Group, ventilation will be applied with PEEP = 8 cmH2O, tidal volume = 8 ml/kg, and respiratory rate to maintain EtCO2 between 35-40, and this ventilation mode was maintained throughout the entire surgery. In the KP Group, ventilation was applied with tidal volume = 8 ml/kg, PEEP = 4 cmH2O, and respiratory rate to maintain EtCO2 between 35 -40, and dynamic compliance was noted 1 minute after the onset of pneumoperitoneum at 12 mmHg. Subsequently, the PEEP value wastitrated every 2 minutes by increasing it by 2 cmH2O until the level providing the highest dynamic compliance value is reached. If the dynamic compliance value does not increase in two consecutive measurements, the previous PEEP value was defined as the patient's "personalized PEEP" value, and ventilation was continued with this PEEP value until the end of the surgery. In all patients, arterial blood gas (ABG) was obtained 10 minutes after anesthesia induction, at the 10th and 30th minutes of pneumoperitoneum, and 10 minutes after pneumoperitoneum is terminated.Patients were transferred to the recovery room after anesthesia is discontinued, and arterial blood gas sampling and lung ultrasound was performed at 30 minutes postoperatively.
On postoperative day 1, presence of atelectasis was assessed with lung ultrasound, and SpO2 was recorded at 4th, 12th, and 24th hours postoperatively. Within 4 hours postoperatively, patients in need of supplemental oxygen were recorded(SpO2 92% was decided as cut-off value). After the 4th hour, the number of patients requiring supplemental oxygen after the 4th hour was recorded and compared in both groups. Data were collected and recorded using a standardized paper-based data collection form. A power analysis measurement (post-hoc test) is planned to be performed. If the power analysis exceeds 80% between the groups, the study will be terminated. Data collection was completed after reaching the planned number of volunteers. The study results will be evaluated using the SPSS statistical analysis program. Numerical data between groups (SP vs. KP) will be evaluated using the ANOVA test or Kruskal Wallis test, while categorical data will be evaluated using the chi-square test or Fisher exact test. P<0.05 will be considered statistically significant, and univariate and multivariate analyses will be performed.
- Conditions
- Obesity (Body Mass Index >30 kg/m2), Atelectasis, Postoperative, PEEP With Dynamic Compliance, Individualized PEEP
- Being tested
- Individualized approach
- Keywords
- obesity, bariatric surgery, postoperative atelectasis, individualized peep
- Medical subject headings
- Obesity, Pulmonary Atelectasis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Individualized approachDevice
individuals were compared by using of a personalized peep or not
| Study group | Role | What they receive |
|---|---|---|
| SP-standard peep | individuals monitored by standard PEEP | |
| KP-individualized peep | individuals monitored by individualized PEEP Receives: Device: Individualized approach |
What is being measured
The primary outcome is the main question the study is designed to answer.
LUSS score (lung ultrasound severity score)
Lung aeration was assessed using the Lung Ultrasound Score (LUS). Each lung was divided into six regions (anterior, lateral, and posterior areas, each subdivided into upper and lower regions), resulting in a total of 12 regions. Each region was scored from 0 to 3 based on ultrasound findings, with higher scores indicating greater loss of lung aeration. The total LUS ranged from 0 to 36.
Measured: 6 months
compliance in individualized and non-individualized peep group
Compliance was assessed intraoperatively in both the individualized PEEP group and the non-individualized (fixed PEEP) group.In the individualized PEEP group, PEEP was titrated based on dynamic compliance, and respiratory system compliance was recorded at the PEEP level that yielded the highest dynamic compliance value for each patient.In the non-individualized PEEP group, a predefined fixed PEEP level was applied throughout the procedure, and respiratory system compliance was measured at this fixed PEEP level.
Measured: 6 months
arterial blood gas analysis
Arterial blood gas analysis was performed to assess arterial oxygenation. The partial pressure of arterial oxygen (PaO₂) was recorded at predefined intraoperative time points and analyzed to determine significant differences between the individualized PEEP and fixed PEEP groups.
Measured: 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Jan 2026
- Study start1 Dec 2024
- Primary completion10 Nov 2025
- Study completion10 Apr 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Obesity (Body Mass Index >30 kg/m2)Studies 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
- Case-control
- Time perspective
- Prospective
- Enrolment
- 40 participants (actual)
- Target duration
- 6 Months
Sponsor and investigators
- Lead sponsor
- Yeditepe University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07345650
- Sponsor's protocol ID
- 2024-KAEK-21/1045
- Status last verified
- Jan 2026
- First submitted
- 7 Jan 2026
- Last updated
- 16 Jan 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- Undecided: The study is not over yet, this is the reason why IPD might not be shared yet.
Study at a glance
From the registry record, last updated by the sponsor on 16 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Dynamic Compliance-Guided Personalized PEEP During Laparoscopic Bariatric Surgery: Effects on Intraoperative Respiratory Parameters
- ClinicalTrials.gov ID
- NCT07345650
- Acronym / sponsor ID
- 2024-KAEK-21/1045
- Conditions
- Obesity (Body Mass Index >30 kg/m2), Atelectasis, Postoperative, PEEP With Dynamic Compliance, Individualized PEEP
- Keywords
- obesity, bariatric surgery, postoperative atelectasis, individualized peep
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 40 participants (actual)
- Lead sponsor
- Yeditepe UniversityUniversity, hospital or other
- Study start
- 1 Dec 2024 (actual)
- Primary completion
- 10 Nov 2025 (actual)
- Study completion
- 10 Apr 2026 (estimated)
- First posted
- 16 Jan 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.
Atelectasis may be encountered in the patient population aged 18-65 years undergoing elective laparoscopic bariatric surgery under general anesthesia with endotracheal intubation. The aim of this study is to compare oxygenation, postoperative atelectasis, and postoperative respiratory complications between the fixed PEEP application (SP Group) and personalized PEEP application (KP Group). In the SP Group, ventilation will be applied with PEEP = 8 cmH2O, tidal volume = 8 ml/kg, and respiratory rate to maintain EtCO2 between 35-40, and this ventilation mode was maintained throughout the entire surgery. In the KP Group, ventilation was applied with tidal volume = 8 ml/kg, PEEP = 4 cmH2O, and respiratory rate to maintain EtCO2 between 35 -40, and dynamic compliance was noted 1 minute after the onset of pneumoperitoneum at 12 mmHg. Subsequently, the PEEP value wastitrated every 2 minutes by increasing it by 2 cmH2O until the level providing the highest dynamic compliance value is reached. If the dynamic compliance value does not increase in two consecutive measurements, the previous PEEP value was defined as the patient's "personalized PEEP" value, and ventilation was continued with this PEEP value until the end of the surgery. In all patients, arterial blood gas (ABG) was obtained 10 minutes after anesthesia induction, at the 10th and 30th minutes of pneumoperitoneum, and 10 minutes after pneumoperitoneum is terminated.Patients were transferred to the recovery room after anesthesia is discontinued, and arterial blood gas sampling and lung ultrasound was performed at 30 minutes postoperatively.
On postoperative day 1, presence of atelectasis was assessed with lung ultrasound, and SpO2 was recorded at 4th, 12th, and 24th hours postoperatively. Within 4 hours postoperatively, patients in need of supplemental oxygen were recorded(SpO2 92% was decided as cut-off value). After the 4th hour, the number of patients requiring supplemental oxygen after the 4th hour was recorded and compared in both groups. Data were collected and recorded using a standardized paper-based data collection form. A power analysis measurement (post-hoc test) is planned to be performed. If the power analysis exceeds 80% between the groups, the study will be terminated. Data collection was completed after reaching the planned number of volunteers. The study results will be evaluated using the SPSS statistical analysis program. Numerical data between groups (SP vs. KP) will be evaluated using the ANOVA test or Kruskal Wallis test, while categorical data will be evaluated using the chi-square test or Fisher exact test. P<0.05 will be considered statistically significant, and univariate and multivariate analyses will be performed.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Target follow-up
- 6 Months
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| SP-standard peep | – | –individuals monitored by standard PEEP |
| KP-individualized peep | – | Device: Individualized approachindividuals monitored by individualized PEEP |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- The study population consisted of adult women and men aged 18 to 65 years who were scheduled for elective laparoscopic bariatric surgery. Eligible participants had an American Society of Anesthesiologists (ASA) physical status of I-III and a body mass index (BMI) greater than 30 kg/m². All participants provided written informed consent prior to enrollment. Patients were excluded if they were younger than 18 years or older than 65 years, were not scheduled for bariatric surgery, had an ASA physical status of IV-V, or a BMI less than 30 kg/m². Additional exclusion criteria included refusal or inability to provide informed consent; a history of chronic obstructive pulmonary disease (COPD) classified as GOLD stage III or IV; severe or uncontrolled bronchial asthma; severe restrictive lung disease; a history of pulmonary metastases or previous thoracic surgery; the requirement for preoperative thoracic drainage; the need for preoperative renal replacement therapy; and congestive heart fail
Key inclusion criteria (1 listed)
- Adult women and men aged 18 to 65 years Scheduled for elective laparoscopic bariatric surgery American Society of Anesthesiologists (ASA) physical status I-III Body mass index (BMI) > 30 kg/m² Provision of written informed consent
Key exclusion criteria (1 listed)
- Age < 18 years or > 65 years Not scheduled for bariatric surgery ASA physical status IV-V Body mass index (BMI) < 30 kg/m² Refusal or inability to provide inHistory of Chronic Obstructive Pulmonary Disease (GOLD III and IV) History of severe/uncontrolled bronchial asthma Severe restrictive lung disease History of pulmonary metastases History of thoracic surgery Requiring preoperative thoracic drainage Requiring preoperative renal replacement therapy Congestive heart failure (NYHA Class III and IV)
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 |
|---|---|---|
| Individualized approachindividuals were compared by using of a personalized peep or not | Device | KP-individualized peep |
Primary outcome
LUSS score (lung ultrasound severity score)
Time frame: 6 months
Lung aeration was assessed using the Lung Ultrasound Score (LUS). Each lung was divided into six regions (anterior, lateral, and posterior areas, each subdivided into upper and lower regions), resulting in a total of 12 regions. Each region was scored from 0 to 3 based on ultrasound findings, with higher scores indicating greater loss of lung aeration. The total LUS ranged from 0 to 36.
compliance in individualized and non-individualized peep group
Time frame: 6 months
Compliance was assessed intraoperatively in both the individualized PEEP group and the non-individualized (fixed PEEP) group.In the individualized PEEP group, PEEP was titrated based on dynamic compliance, and respiratory system compliance was recorded at the PEEP level that yielded the highest dynamic compliance value for each patient.In the non-individualized PEEP group, a predefined fixed PEEP level was applied throughout the procedure, and respiratory system compliance was measured at this fixed PEEP level.
arterial blood gas analysis
Time frame: 6 months
Arterial blood gas analysis was performed to assess arterial oxygenation. The partial pressure of arterial oxygen (PaO₂) was recorded at predefined intraoperative time points and analyzed to determine significant differences between the individualized PEEP and fixed PEEP groups.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 16 Jan 2026.
- Individual participant dataSharing planned: Undecided. The study is not over yet, this is the reason why IPD might not be shared yet.
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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 Obesity (Body Mass Index >30 kg/m2) and Atelectasis, Postoperative, run by Yeditepe University 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: under way, not looking for participants, as of the sponsor's last update on 16 Jan 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?
This study is still under way. Results are not available in the source record yet.
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?
LUSS score (lung ultrasound severity score) (time frame: 6 months). The study lists 3 primary outcomes in all. 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 16 Jan 2026.