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Perioperative Respiratory Function in Sleeve Gastrectomy

Perioperative Oxygenation and Respiratory Function in Obese Patients Undergoing Laparoscopic Sleeve Gastrectomy: A Retrospective Cohort Study

Status
Completed
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07629102
Enrollment
53
Registered
2026-06-05
Start date
2026-04-01
Completion date
2026-05-20
Last updated
2026-06-05

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Obesity (BMI > 35), Oxygenation, Peep Titration in Lung Protective Ventilation, Sleeve Gastrectomy

Keywords

Obesity, laparoscopic sleeve gastrectomy, PEEP titration, perioperative oxygenation

Brief 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. 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.

Interventions

OTHERPEEP 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.

OTHERPEEP 5 cmH2O

Patients were ventilated with a positive end-expiratory pressure (PEEP) of 5 cmH₂O without recruitment maneuvers

Sponsors

Istanbul Saglik Bilimleri University
Lead SponsorOTHER

Study design

Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
OTHER
Masking
NONE

Masking description

The study was conducted retrospectively.

Eligibility

Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No

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

Design outcomes

Primary

MeasureTime frameDescription
PaO2/FiO2 ratioT0: immediately after endotracheal intubation • T1: 10 minutes after establishment of pneumoperitoneum and achievement of the target intra-abdominal pressure • T2: 5 minutes afteThe primary outcome of the study was perioperative oxygenation assessed by serial PaO2/FiO2 ratio measurements.

Secondary

MeasureTime frameDescription
Postoperative pulmonary function testsWere evaluated before the surgery and on the day of hospital dischargeforced expiratory volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio
Intensive care unit admissionPostoperative day 0Patients requiring intensive care admission
PaCO₂, pH, oxygen saturationT0: immediately after endotracheal intubation • T1: 10 minutes after establishment of pneumoperitoneum and achievement of the target intra-abdominal pressure • T2: 5 minutes afteBlood gas analyses parameters
Hospital length of stayOn which day the patients were dischargedHow many days did the patient stay in the hospital?

Countries

Turkey (Türkiye)

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jun 6, 2026