Flow-Controlled vs Volume-Controlled Ventilation in Morbidly Obese Patients Undergoing Laparoscopic Bariatric Surgery

NCT07641829 | Recruiting

• 1 other identifier: E-25-418
• Study Type: observational
• Target: 34
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to compare the effects of flow-controlled ventilation (FCV) and volume-controlled ventilation (VCV) on hemodynamic and respiratory parameters in obese patients undergoing elective laparoscopic bariatric surgery. The main questions it aims to answer are: Does FCV provide better intraoperative hemodynamic and respiratory stability compared to VCV during laparoscopic bariatric surgery? Is FCV a safe and feasible ventilation strategy under high intraabdominal pressure and position changes required in bariatric surgery? Researchers will compare FCV group to VCV group to see if FCV improves intraoperative respiratory mechanics and hemodynamic parameters. Participants will: Undergo elective laparoscopic bariatric surgery with BMI \>40 kg/m² (ASA I-III) Receive either flow-controlled or volume-controlled ventilation with individualized PEEP and tidal volume of 6-8 ml/kg predicted body weight Have intraoperative hemodynamic and respiratory parameters monitored at regular intervals, including arterial blood gas analysis Be followed postoperatively for oxygen therapy requirement and intensive care need

Conditions

Obesity, Morbid; Bariatric Surgery (Sleeve Gastrectomy ); Mechanical Ventilation

Keywords

Flow-controlled ventilation; Volume-controlled ventilation; Respiratory mechanics; Lung-protective ventilation; Bariatric surgery

Outcome Measures

Primary Outcomes (2)

• Intraoperative Respiratory Mechanics

  Comparison of driving pressure between FCV and VCV groups at defined intraoperative time points.

  From intubation to end of surgery, measured after intubation, after insufflation, and at 30-minute intervals intraoperatively

• Mean Arterial Pressure

  Comparison of mean arterial pressure (MAP) between FCV and VCV groups at defined intraoperative time points.

  From preoperative baseline to end of surgery, measured before surgery, after intubation, after insufflation, at 30-minute intervals intraoperatively, and at end of surgery

Secondary Outcomes (4)

• Pa02/Fi02 ratio

  From intubation to end of surgery, measured after intubation, after insufflation, at 30-minute intervals intraoperatively and at the end of the surgery.

• Postoperative Oxygen Theraphy Need

  Within 24 hours after surgery

• Postoperative Intensive Unit Admission

  Within 24 hours after surgery

• Arterial Partial Pressure of Carbon Dioxide (PaCO2)

  From intubation to the end of surgery, measured after intubation, after insufflation, and at 30-minute intervals intraoperatively and at the end of the operation

Study Arms (2)

FCV Group

Patients undergoing elective laparoscopic bariatric surgery managed with flow-controlled ventilation (FCV) with tidal volume of 6-8 ml/kg predicted body weight and individualized PEEP based on compliance following CO₂ insufflation.

Device: Flow-Controlled Ventilation (FCV)

VCV Group

Patients undergoing elective laparoscopic bariatric surgery managed with volume-controlled ventilation (VCV) with tidal volume of 6-8 ml/kg predicted body weight and PEEP titration performed in eligible patients. Data collected retrospectively.

Device: Volume-Controlled Ventilation (VCV)

Interventions

Flow-Controlled Ventilation (FCV) DEVICE

Patients were ventilated using flow-controlled ventilation with a tidal volume of 6-8 ml/kg predicted body weight. PEEP was individualized based on respiratory compliance following CO₂ insufflation.

Also known as: FCV

FCV Group

Volume-Controlled Ventilation (VCV) DEVICE

Patients were ventilated using volume-controlled ventilation with a tidal volume of 6-8 ml/kg predicted body weight. PEEP titration was performed in eligible patients.

VCV Group

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Adult morbidly obese patients (BMI ≥40 kg/m²) aged 18-65 years, classified as ASA I-III, scheduled for elective laparoscopic bariatric surgery at Ankara Training and Research Hospital.

You may qualify if:

• Age between 18 and 65 years American Society of Anesthesiologists (ASA) physical status I, II, or III Body Mass Index (BMI) ≥ 40 kg/m² Scheduled for elective laparoscopic bariatric surgery Willing to participate in the study

You may not qualify if:

• ASA physical status IV or V Emergency surgical procedures Pregnant patients Patients requiring vasopressor support to maintain mean arterial pressure above 65 mmHg intraoperatively Patients with advanced pulmonary disease Patients who decline to participate in the study

Sponsors & Collaborators

• Ankara Training and Research Hospital: lead

Study Sites (1)

Ankara Education and Research Hospital

Ankara, 06230, Turkey (Türkiye)

RECRUITING

MeSH Terms

Conditions

Obesity, Morbid

Condition Hierarchy (Ancestors)

Obesity; Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Central Study Contacts

Tugce Ozdogan, MD

CONTACT

+90 5353588818; tugceeskin@yahoo.com.tr

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: OTHER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: MD

Study Record Dates

• First Submitted: June 1, 2026
• First Posted: June 11, 2026
• Study Start: March 15, 2026
• Primary Completion (Estimated): August 1, 2026
• Study Completion (Estimated): August 1, 2026
• Last Updated: June 11, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, ICF
• Time Frame: Beginning 6 months after publication and ending 5 years following article publication
• Access Criteria: Individual participant data will be available upon reasonable request to the corresponding author.

Locations

TU (1)