Perioperative Respiratory Function in Sleeve Gastrectomy

June 1, 2026 updated by: Taner Abdullah, Istanbul Saglik Bilimleri University

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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

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 Type

Interventional

Enrollment (Actual)

53

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Turkey (Türkiye)
      • Istanbul, Turkey (Türkiye)
        • Basaksehir Cam and Sakura City Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

- American Society of Anesthesiologists (ASA) physical status I-III who underwent elective laparoscopic sleeve gastrectomy

Exclusion Criteria:

  • revision bariatric surgery
  • gastric bypass surgery
  • conversion to open surgery
  • incomplete perioperative records
  • missing arterial blood gas measurements
  • unavailable postoperative pulmonary function tests

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: PEEP 5/no recruitment maneuver
Patients were ventilated with a positive end-expiratory pressure (PEEP) of 5 cmH₂O without recruitment maneuvers
Other: PEEP 5 cmH2O
Patients were ventilated with a positive end-expiratory pressure (PEEP) of 5 cmH₂O without recruitment maneuvers
Other: PEEP 8/recruitment maneuver
Patients received a protective ventilation strategy consisting of PEEP 8 cmH₂O combined with repeated recruitment maneuvers performed after pneumoperitoneum insufflation and before extubation
Other: PEEP 8 cmH2O + Recruitment Maneuvers
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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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.
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 Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postoperative pulmonary function tests
Time Frame: Were evaluated before the surgery and on the day of hospital discharge
forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio
Were evaluated before the surgery and on the day of hospital discharge
Intensive care unit admission
Time Frame: Postoperative day 0
Patients requiring intensive care admission
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
Blood gas analyses parameters
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
How many days did the patient stay in the hospital?
On which day the patients were discharged

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Istanbul Saglik Bilimleri University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 1, 2026

Primary Completion (Actual)

April 15, 2026

Study Completion (Actual)

May 20, 2026

Study Registration Dates

First Submitted

May 22, 2026

First Submitted That Met QC Criteria

June 1, 2026

First Posted (Actual)

June 5, 2026

Study Record Updates

Last Update Posted (Actual)

June 5, 2026

Last Update Submitted That Met QC Criteria

June 1, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2026-134

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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