Obesity (BMI > 35)NCT07629102
Perioperative Respiratory Function in Sleeve Gastrectomy
A study testing PEEP 8 cmH2O + Recruitment Maneuvers and PEEP 5 cmH2O in people with Obesity (BMI > 35) and Sleeve Gastrectomy, run by Istanbul Saglik Bilimleri University at 1 site in Turkey (Türkiye).
Trial summary
This retrospective single-center cohort study aims to evaluate the effects of two intraoperative ventilation strategies on perioperative oxygenation and respiratory outcomes in obese patients undergoing laparoscopic sleeve gastrectomy. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Obesity (BMI > 35), Sleeve Gastrectomy, Oxygenation
- What is being tested?
- PEEP 8 cmH2O + Recruitment Maneuvers and PEEP 5 cmH2O
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 53 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Apr 2026to 20 May 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 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- American Society of Anesthesiologists (ASA) physical status I-III who underwent elective laparoscopic sleeve gastrectomy
Who cannot join
- revision bariatric surgery
- gastric bypass surgery
- conversion to open surgery
- incomplete perioperative records
- missing arterial blood gas measurements
- unavailable postoperative pulmonary function tests
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Basaksehir Cam and Sakura City Hospital
Istanbul
About this study
Official title: Perioperative Oxygenation and Respiratory Function in Obese Patients Undergoing Laparoscopic Sleeve Gastrectomy: A Retrospective Cohort Study
This retrospective single-center cohort study aims to evaluate the effects of two intraoperative ventilation strategies on perioperative oxygenation and respiratory outcomes in obese patients undergoing laparoscopic sleeve gastrectomy. Patients were managed using standardized anesthetic and ventilatory protocols with volume-controlled ventilation and fixed inspired oxygen fraction (FiO₂ 45%). The study compares conventional ventilation with PEEP 5 cmH₂O versus a protective ventilation strategy consisting of PEEP 8 cmH₂O combined with repeated recruitment maneuvers performed after pneumoperitoneum establishment and before extubation. Perioperative oxygenation is assessed using serial PaO₂/FiO₂ measurements obtained immediately after intubation, after pneumoperitoneum establishment, and after extubation. Secondary outcomes include perioperative arterial blood gas variables, postoperative spirometric parameters, lactate levels, ICU admission, and hospital length of stay. The study aims to determine whether escalation of intraoperative ventilatory support provides incremental respiratory benefit in contemporary bariatric anesthesia practice.
Read the detailed description
Obesity is associated with substantial alterations in respiratory physiology, including reduced functional residual capacity, decreased respiratory compliance, impaired diaphragmatic excursion, and increased susceptibility to perioperative atelectasis and hypoxemia. These physiologic changes become more pronounced during general anesthesia and laparoscopic surgery because of positive-pressure ventilation and carbon dioxide pneumoperitoneum. Consequently, obese patients undergoing bariatric surgery represent a particularly vulnerable population for perioperative respiratory impairment.
Lung-protective ventilation strategies incorporating low tidal volume ventilation, positive end-expiratory pressure (PEEP), and recruitment maneuvers have been increasingly utilized in obese surgical patients to improve oxygenation and reduce atelectatic changes. However, despite improvements in intraoperative respiratory mechanics and oxygenation reported in previous studies, the clinical significance and incremental benefit of intensified ventilation strategies remain uncertain, particularly in contemporary bariatric anesthesia settings where protective ventilation principles are already routinely applied.
This retrospective single-center cohort study evaluates perioperative oxygenation and respiratory outcomes in obese patients undergoing elective laparoscopic sleeve gastrectomy between January 2021 and January 2026. All patients were managed using standardized anesthetic and surgical protocols, including volume-controlled ventilation with tidal volumes of 6-8 mL/kg ideal body weight and fixed inspired oxygen fraction (FiO₂ 45%).
Patients were divided into two groups according to intraoperative ventilation strategy. The first group received conventional ventilation with PEEP 5 cmH₂O without recruitment maneuvers. The second group received a protective ventilation strategy consisting of PEEP 8 cmH₂O combined with repeated recruitment maneuvers performed after pneumoperitoneum establishment and before extubation.
Perioperative oxygenation was assessed using serial PaO₂/FiO₂ measurements obtained immediately after endotracheal intubation (T0), 10 minutes after pneumoperitoneum establishment (T1), and 5 minutes after extubation (T2). Secondary outcomes included arterial blood gas variables, postoperative spirometric parameters, lactate levels, intensive care unit admission, and hospital length of stay.
The primary objective of the study is to determine whether escalation from conventional PEEP 5 cmH₂O ventilation to PEEP 8 cmH₂O combined with recruitment maneuvers provides incremental perioperative respiratory benefit in obese patients undergoing laparoscopic sleeve gastrectomy within a standardized contemporary bariatric anesthesia setting.
- Conditions
- Obesity (BMI > 35), Sleeve Gastrectomy, Oxygenation, Peep Titration in Lung Protective Ventilation
- Being tested
- PEEP 8 cmH2O + Recruitment Maneuvers, PEEP 5 cmH2O
- Keywords
- Obesity, laparoscopic sleeve gastrectomy, PEEP titration, perioperative oxygenation
- Medical subject headings
- Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PEEP 8 cmH2O + Recruitment ManeuversOther
Recruitment maneuvers were performed using a stepwise PEEP increase strategy. PEEP levels were gradually increased over consecutive respiratory cycles up to 15-20 cmH₂O and subsequently reduced to the assigned maintenance PEEP level.
PEEP 5 cmH2OOther
Patients were ventilated with a positive end-expiratory pressure (PEEP) of 5 cmH₂O without recruitment maneuvers
| Study group | Role | What they receive |
|---|---|---|
| PEEP 5/no recruitment maneuver | Other | Patients were ventilated with a positive end-expiratory pressure (PEEP) of 5 cmH₂O without recruitment maneuvers Receives: Other: PEEP 5 cmH2O |
| PEEP 8/recruitment maneuver | Other | Patients received a protective ventilation strategy consisting of PEEP 8 cmH₂O combined with repeated recruitment maneuvers performed after pneumoperitoneum insufflation and before extubation Receives: Other: PEEP 8 cmH2O + Recruitment Maneuvers |
What is being measured
The primary outcome is the main question the study is designed to answer.
PaO2/FiO2 ratio
The primary outcome of the study was perioperative oxygenation assessed by serial PaO2/FiO2 ratio measurements.
Measured: T0: immediately after endotracheal intubation • T1: 10 minutes after establishment of pneumoperitoneum and achievement of the target intra-abdominal pressure • T2: 5 minutes afte
Secondary outcomes (4)
Postoperative pulmonary function tests
forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio
Measured: Were evaluated before the surgery and on the day of hospital discharge
Intensive care unit admission
Patients requiring intensive care admission
Measured: Postoperative day 0
PaCO₂, pH, oxygen saturation
Blood gas analyses parameters
Measured: T0: immediately after endotracheal intubation • T1: 10 minutes after establishment of pneumoperitoneum and achievement of the target intra-abdominal pressure • T2: 5 minutes afte
Hospital length of stay
How many days did the patient stay in the hospital?
Measured: On which day the patients were discharged
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Jun 2026
- Study start1 Apr 2026
- Primary completion15 Apr 2026
- Study completion20 May 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Obesity (BMI > 35)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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 53 participants (actual)
Sponsor and investigators
- Lead sponsor
- Istanbul Saglik Bilimleri University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Taner Abdullah, Istanbul Saglik Bilimleri University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07629102
- Sponsor's protocol ID
- 2026-134
- Status last verified
- May 2026
- First submitted
- 22 May 2026
- Last updated
- 5 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 5 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Perioperative Oxygenation and Respiratory Function in Obese Patients Undergoing Laparoscopic Sleeve Gastrectomy: A Retrospective Cohort Study
- ClinicalTrials.gov ID
- NCT07629102
- Acronym / sponsor ID
- 2026-134
- Conditions
- Obesity (BMI > 35), Sleeve Gastrectomy, Oxygenation, Peep Titration in Lung Protective Ventilation
- Keywords
- Obesity, laparoscopic sleeve gastrectomy, PEEP titration, perioperative oxygenation
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 53 participants (actual)
- Lead sponsor
- Istanbul Saglik Bilimleri UniversityUniversity, hospital or other
- Study start
- 1 Apr 2026 (actual)
- Primary completion
- 15 Apr 2026 (actual)
- Study completion
- 20 May 2026 (actual)
- First posted
- 5 Jun 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 retrospective single-center cohort study aims to evaluate the effects of two intraoperative ventilation strategies on perioperative oxygenation and respiratory outcomes in obese patients undergoing laparoscopic sleeve gastrectomy. Patients were managed using standardized anesthetic and ventilatory protocols with volume-controlled ventilation and fixed inspired oxygen fraction (FiO₂ 45%). The study compares conventional ventilation with PEEP 5 cmH₂O versus a protective ventilation strategy consisting of PEEP 8 cmH₂O combined with repeated recruitment maneuvers performed after pneumoperitoneum establishment and before extubation. Perioperative oxygenation is assessed using serial PaO₂/FiO₂ measurements obtained immediately after intubation, after pneumoperitoneum establishment, and after extubation. Secondary outcomes include perioperative arterial blood gas variables, postoperative spirometric parameters, lactate levels, ICU admission, and hospital length of stay. The study aims to determine whether escalation of intraoperative ventilatory support provides incremental respiratory benefit in contemporary bariatric anesthesia practice.
Detailed description
Obesity is associated with substantial alterations in respiratory physiology, including reduced functional residual capacity, decreased respiratory compliance, impaired diaphragmatic excursion, and increased susceptibility to perioperative atelectasis and hypoxemia. These physiologic changes become more pronounced during general anesthesia and laparoscopic surgery because of positive-pressure ventilation and carbon dioxide pneumoperitoneum. Consequently, obese patients undergoing bariatric surgery represent a particularly vulnerable population for perioperative respiratory impairment.
Lung-protective ventilation strategies incorporating low tidal volume ventilation, positive end-expiratory pressure (PEEP), and recruitment maneuvers have been increasingly utilized in obese surgical patients to improve oxygenation and reduce atelectatic changes. However, despite improvements in intraoperative respiratory mechanics and oxygenation reported in previous studies, the clinical significance and incremental benefit of intensified ventilation strategies remain uncertain, particularly in contemporary bariatric anesthesia settings where protective ventilation principles are already routinely applied.
This retrospective single-center cohort study evaluates perioperative oxygenation and respiratory outcomes in obese patients undergoing elective laparoscopic sleeve gastrectomy between January 2021 and January 2026. All patients were managed using standardized anesthetic and surgical protocols, including volume-controlled ventilation with tidal volumes of 6-8 mL/kg ideal body weight and fixed inspired oxygen fraction (FiO₂ 45%).
Patients were divided into two groups according to intraoperative ventilation strategy. The first group received conventional ventilation with PEEP 5 cmH₂O without recruitment maneuvers. The second group received a protective ventilation strategy consisting of PEEP 8 cmH₂O combined with repeated recruitment maneuvers performed after pneumoperitoneum establishment and before extubation.
Perioperative oxygenation was assessed using serial PaO₂/FiO₂ measurements obtained immediately after endotracheal intubation (T0), 10 minutes after pneumoperitoneum establishment (T1), and 5 minutes after extubation (T2). Secondary outcomes included arterial blood gas variables, postoperative spirometric parameters, lactate levels, intensive care unit admission, and hospital length of stay.
The primary objective of the study is to determine whether escalation from conventional PEEP 5 cmH₂O ventilation to PEEP 8 cmH₂O combined with recruitment maneuvers provides incremental perioperative respiratory benefit in obese patients undergoing laparoscopic sleeve gastrectomy within a standardized contemporary bariatric anesthesia setting.
Study design
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| PEEP 5/no recruitment maneuver | Other | Other: PEEP 5 cmH2OPatients were ventilated with a positive end-expiratory pressure (PEEP) of 5 cmH₂O without recruitment maneuvers |
| PEEP 8/recruitment maneuver | Other | Other: PEEP 8 cmH2O + Recruitment ManeuversPatients received a protective ventilation strategy consisting of PEEP 8 cmH₂O combined with repeated recruitment maneuvers performed after pneumoperitoneum insufflation and before extubation |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- American Society of Anesthesiologists (ASA) physical status I-III who underwent elective laparoscopic sleeve gastrectomy
Key exclusion criteria (6 listed)
- revision bariatric surgery
- gastric bypass surgery
- conversion to open surgery
- incomplete perioperative records
- missing arterial blood gas measurements
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 8 cmH2O + Recruitment ManeuversRecruitment maneuvers were performed using a stepwise PEEP increase strategy. PEEP levels were gradually increased over consecutive respiratory cycles up to 15-20 cmH₂O and subsequently reduced to the assigned maintenance PEEP level. | Other | PEEP 8/recruitment maneuver |
| PEEP 5 cmH2OPatients were ventilated with a positive end-expiratory pressure (PEEP) of 5 cmH₂O without recruitment maneuvers | Other | PEEP 5/no recruitment maneuver |
Primary outcome
PaO2/FiO2 ratio
Time frame: T0: immediately after endotracheal intubation • T1: 10 minutes after establishment of pneumoperitoneum and achievement of the target intra-abdominal pressure • T2: 5 minutes afte
The primary outcome of the study was perioperative oxygenation assessed by serial PaO2/FiO2 ratio measurements.
4 secondary outcomes
Postoperative pulmonary function tests
Time frame: Were evaluated before the surgery and on the day of hospital discharge
Intensive care unit admission
Time frame: Postoperative day 0
PaCO₂, pH, oxygen saturation
Time frame: T0: immediately after endotracheal intubation • T1: 10 minutes after establishment of pneumoperitoneum and achievement of the target intra-abdominal pressure • T2: 5 minutes afte
Hospital length of stay
Time frame: On which day the patients were discharged
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 5 Jun 2026.
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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?
A study testing PEEP 8 cmH2O + Recruitment Maneuvers and PEEP 5 cmH2O in people with Obesity (BMI > 35) and Sleeve Gastrectomy, run by Istanbul Saglik Bilimleri 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 6 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 5 Jun 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?
PaO2/FiO2 ratio (time frame: T0: immediately after endotracheal intubation • T1: 10 minutes after establishment of pneumoperitoneum and achievement of the target intra-abdominal pressure • T2: 5 minutes afte). 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 5 Jun 2026.