AnesthesiaNCT07875530
VC-AF vs FCV in Obese Patients Undergoing Laparoscopic Surgery
An observational study of Anesthesia and Mechanical Ventilation, run by Kocaeli University at 1 site in Turkey (Türkiye).
Trial summary
Obesity adversely affects respiratory physiology by reducing lung volumes and compliance and increasing airway resistance and alveolar collapse. These effects are further aggravated by pneumoperitoneum during laparoscopic surgery, increasing the risk of impaired oxygenation and ventilator-induced lung injury (VILI). Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Anesthesia, Mechanical Ventilation, Obesity
- How many people
- 78 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 21 Sep 2026to 21 Sep 2027
- 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
- Healthy volunteers accepted
- Adult, Older adult
Study population: Patients with a BMI ≥30 kg/m² undergoing laparoscopic surgery under general anesthesia
Who may be able to join
- Age ≥18 years Body mass index (BMI) ≥30 kg/m² American Society of Anesthesiologists (ASA) Physical Status I-III Scheduled to undergo elective laparoscopic surgery under general anesthesia
Who cannot join
- Pregnancy Emergency surgery Presence of a cardiac pacemaker Chronic obstructive pulmonary disease (COPD)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Turkey (Türkiye)1 site, 1 recruiting
- Recruiting
Kocaeli University Faculty of Medicine
Kocaeli, Izmit, 41100
Elif Balcı Koç, MD, +90 543 487 10 38, elfblc67@gmail.com
About this study
Official title: Comparison of VC-AF and FCV Mechanical Ventilation Modes in Obese Patients Undergoing Laparoscopic Surgery
Obesity adversely affects respiratory physiology by reducing lung volumes and compliance and increasing airway resistance and alveolar collapse. These effects are further aggravated by pneumoperitoneum during laparoscopic surgery, increasing the risk of impaired oxygenation and ventilator-induced lung injury (VILI).
Mechanical power (MP) reflects the total energy transferred to the respiratory system during mechanical ventilation and is influenced by tidal volume, respiratory rate, airway pressures, flow, and PEEP. Increased airway and driving pressures may contribute to higher mechanical power and lung injury, particularly in obese patients undergoing laparoscopic surgery.
This study aims to compare flow-controlled ventilation (FCV) and volume-controlled ventilation with autoflow (VC-AF) in obese patients undergoing laparoscopic surgery in terms of airway pressures, driving pressure, and mechanical power. The investigators hypothesize that FCV may reduce airway pressures, driving pressure, and mechanical power compared with VC-AF, potentially decreasing the risk of VILI. The effect of FCV on oxygenation will also be evaluated as a secondary outcome.
Read the detailed description
Obesity is an important risk factor that adversely affects respiratory physiology during the perioperative period, leading to reduced lung volumes, increased airway resistance, and early alveolar collapse. During laparoscopic surgery, pneumoperitoneum and increased intra-abdominal pressure further reduce lung volumes, decrease lung compliance, and promote alveolar collapse. Therefore, obese patients represent a high-risk population for both impaired oxygenation and ventilator-induced lung injury (VILI) during the perioperative period.
Ventilator-induced lung injury is associated not only with high airway pressures and tidal volumes but also with the total amount of energy transferred to the lungs during mechanical ventilation. In this context, mechanical power is considered a comprehensive parameter reflecting the combined effects of tidal volume, respiratory rate, airway pressures, flow, and PEEP. Mechanical power is calculated using ventilation parameters according to the following formula:
MP = 0.098 × RR × VT (L) × (PIP - 0.5 × Driving Pressure) Airway pressures, particularly driving pressure, are key components of mechanical power, and increases in these parameters are closely associated with lung injury.
In obese patients undergoing ventilation during pneumoperitoneum, increased intrathoracic pressure and reduced lung compliance may result in higher airway pressures. This may increase mechanical power and consequently increase the risk of lung injury.
The present study aims to compare the effects of flow-controlled ventilation (FCV) and volume-controlled ventilation with autoflow (VC-AF) on airway pressures, driving pressure, and mechanical power in obese patients undergoing laparoscopic surgery. The investigators hypothesize that, compared with VC-AF, FCV may reduce mechanical power by generating lower airway pressures and driving pressures, thereby potentially reducing the risk of ventilator-induced lung injury. In addition, whether FCV improves oxygenation by providing more homogeneous alveolar ventilation will be evaluated as a secondary outcome.
- Conditions
- Anesthesia, Mechanical Ventilation, Obesity
- Keywords
- Flow-Controlled Ventilation (FCV), Volume-Controlled Ventilation (VCV), Laparoscopic Surgery Obese Patient, Obese Patients, Intraoperative Mechanical Ventilation, Pneumoperitoneum
- Medical subject headings
- Obesity, Pneumoperitoneum
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Flow-Controlled Ventilation (FCV) | Not described | |
| Volume-Controlled Ventilation (VCV) | Not described |
What is being measured
The primary outcome is the main question the study is designed to answer.
Mechanical Power (J/min)
Data will be recorded during surgery
Measured: peroperative
Driving Pressure (cmH₂O)
Data will be recorded during surgery
Measured: peroperative
Plateau Airway Pressure (cmH₂O)
Data will be recorded during surgery
Measured: peroperative
Peak Airway Pressure (cmH₂O)
Data will be recorded during surgery
Measured: peroperative
Secondary outcomes (1)
Oxygenation Assessed by PaO₂/FiO₂ Ratio
Data will be recorded during surgery
Measured: peroperative
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Oct 2026
- Study start21 Sep 2026 (estimated)
- Primary completion21 Jun 2027 (estimated)
- Study completion21 Sep 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for AnesthesiaStudies 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
- 78 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Kocaeli University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Elif Balcı Koç, Kocaeli University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07875530
- Sponsor's protocol ID
- KAEK/14.bI.09
- Status last verified
- Oct 2026
- First submitted
- 15 Sep 2026
- Last updated
- 15 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 15 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of VC-AF and FCV Mechanical Ventilation Modes in Obese Patients Undergoing Laparoscopic Surgery
- ClinicalTrials.gov ID
- NCT07875530
- Acronym / sponsor ID
- KAEK/14.bI.09
- Conditions
- Anesthesia, Mechanical Ventilation, Obesity
- Keywords
- Flow-Controlled Ventilation (FCV), Volume-Controlled Ventilation (VCV), Laparoscopic Surgery Obese Patient, Obese Patients, Intraoperative Mechanical Ventilation, Pneumoperitoneum
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 78 participants (estimated)
- Lead sponsor
- Kocaeli UniversityUniversity, hospital or other
- Study start
- 21 Sep 2026 (estimated)
- Primary completion
- 21 Jun 2027 (estimated)
- Study completion
- 21 Sep 2027 (estimated)
- First posted
- 15 Oct 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.
Obesity adversely affects respiratory physiology by reducing lung volumes and compliance and increasing airway resistance and alveolar collapse. These effects are further aggravated by pneumoperitoneum during laparoscopic surgery, increasing the risk of impaired oxygenation and ventilator-induced lung injury (VILI).
Mechanical power (MP) reflects the total energy transferred to the respiratory system during mechanical ventilation and is influenced by tidal volume, respiratory rate, airway pressures, flow, and PEEP. Increased airway and driving pressures may contribute to higher mechanical power and lung injury, particularly in obese patients undergoing laparoscopic surgery.
This study aims to compare flow-controlled ventilation (FCV) and volume-controlled ventilation with autoflow (VC-AF) in obese patients undergoing laparoscopic surgery in terms of airway pressures, driving pressure, and mechanical power. The investigators hypothesize that FCV may reduce airway pressures, driving pressure, and mechanical power compared with VC-AF, potentially decreasing the risk of VILI. The effect of FCV on oxygenation will also be evaluated as a secondary outcome.
Detailed description
Obesity is an important risk factor that adversely affects respiratory physiology during the perioperative period, leading to reduced lung volumes, increased airway resistance, and early alveolar collapse. During laparoscopic surgery, pneumoperitoneum and increased intra-abdominal pressure further reduce lung volumes, decrease lung compliance, and promote alveolar collapse. Therefore, obese patients represent a high-risk population for both impaired oxygenation and ventilator-induced lung injury (VILI) during the perioperative period.
Ventilator-induced lung injury is associated not only with high airway pressures and tidal volumes but also with the total amount of energy transferred to the lungs during mechanical ventilation. In this context, mechanical power is considered a comprehensive parameter reflecting the combined effects of tidal volume, respiratory rate, airway pressures, flow, and PEEP. Mechanical power is calculated using ventilation parameters according to the following formula:
MP = 0.098 × RR × VT (L) × (PIP - 0.5 × Driving Pressure) Airway pressures, particularly driving pressure, are key components of mechanical power, and increases in these parameters are closely associated with lung injury.
In obese patients undergoing ventilation during pneumoperitoneum, increased intrathoracic pressure and reduced lung compliance may result in higher airway pressures. This may increase mechanical power and consequently increase the risk of lung injury.
The present study aims to compare the effects of flow-controlled ventilation (FCV) and volume-controlled ventilation with autoflow (VC-AF) on airway pressures, driving pressure, and mechanical power in obese patients undergoing laparoscopic surgery. The investigators hypothesize that, compared with VC-AF, FCV may reduce mechanical power by generating lower airway pressures and driving pressures, thereby potentially reducing the risk of ventilator-induced lung injury. In addition, whether FCV improves oxygenation by providing more homogeneous alveolar ventilation will be evaluated as a secondary outcome.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Flow-Controlled Ventilation (FCV) | – | – |
| Volume-Controlled Ventilation (VCV) | – | – |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Patients with a BMI ≥30 kg/m² undergoing laparoscopic surgery under general anesthesia
Key inclusion criteria (1 listed)
- Age ≥18 years Body mass index (BMI) ≥30 kg/m² American Society of Anesthesiologists (ASA) Physical Status I-III Scheduled to undergo elective laparoscopic surgery under general anesthesia
Key exclusion criteria (1 listed)
- Pregnancy Emergency surgery Presence of a cardiac pacemaker Chronic obstructive pulmonary disease (COPD)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Mechanical Power (J/min)
Time frame: peroperative
Data will be recorded during surgery
Driving Pressure (cmH₂O)
Time frame: peroperative
Data will be recorded during surgery
Plateau Airway Pressure (cmH₂O)
Time frame: peroperative
Data will be recorded during surgery
Peak Airway Pressure (cmH₂O)
Time frame: peroperative
Data will be recorded during surgery
1 secondary outcome
Oxygenation Assessed by PaO₂/FiO₂ Ratio
Time frame: peroperative
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 15 Oct 2026.
- Individual participant dataSharing planned: Yes
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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.
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 Anesthesia and Mechanical Ventilation, run by Kocaeli 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: looking for participants now, as of the sponsor's last update on 15 Oct 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?
Contact Elif Balcı Koç, MD (+90 543 487 10 38, elfblc67@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Mechanical Power (J/min) (time frame: peroperative). The study lists 4 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 15 Oct 2026.