ObesityLOWBARNCT07230704
Effects of Low-Flow and Standard-Flow Sevoflurane Anesthesia on Inflammatory Markers in Bariatric Surgery
An observational study of Obesity and Inflammation, run by Adana City Training and Research Hospital at 1 site in Turkey (Türkiye).
Trial summary
This retrospective observational study aimed to compare the effects of low-flow and standard-flow sevoflurane anesthesia on perioperative inflammatory responses in patients undergoing laparoscopic sleeve gastrectomy for obesity. Read more about this study
- Who is it for?
- Ages 18 to 60 years
- Conditions the study is for
- Obesity, Inflammation, Bariatric Surgery Candidate
- How many people
- 155 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Jan 2022to 31 Jan 2025
- Phase
- Observational
- 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 60 years
- All sexes
- No healthy volunteers
- Adult
Study population: Retrospective analysis of 155 adult patients who underwent laparoscopic sleeve gastrectomy under general anesthesia between January 2022 and January 2025 at Adana City Training and Research Hospital. Patients were grouped according to the fresh gas flow rate used during anesthesia (low-flow vs. standard-flow sevoflurane).
Who may be able to join
- Adult patients aged 18-60 years
- Underwent laparoscopic sleeve gastrectomy under general anesthesia
- Received low-flow or standard-flow sevoflurane anesthesia
- ASA physical status I-III
- Complete perioperative records available
Who cannot join
- Conversion to open surgery
- Incomplete or missing data
- Significant comorbidities (e.g., severe cardiac, hepatic, or renal dysfunction)
- Perioperative complications unrelated to anesthesia
- Age <18 or >60 years
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Adana City Training and Research Hospital
Adana, Adana, 010650
About this study
Official title: Effects of Low-Flow and Standard-Flow Sevoflurane Anesthesia on Perioperative Inflammation in Bariatric Surgery
This retrospective observational study aimed to compare the effects of low-flow and standard-flow sevoflurane anesthesia on perioperative inflammatory responses in patients undergoing laparoscopic sleeve gastrectomy for obesity. Data were obtained from the anesthesia and laboratory records of 155 adult patients who received either low-flow (1 L/min) or standard-flow (4 L/min) sevoflurane anesthesia between January 2022 and January 2025 at Adana City Training and Research Hospital. Preoperative and postoperative inflammatory markers, including C-reactive protein (CRP), neutrophil-to-lymphocyte ratio (NLR), and red cell distribution width (RDW), were recorded and compared between the two groups. Hemodynamic parameters such as mean arterial pressure and heart rate were also analyzed to assess intraoperative stability. The primary objective of the study was to evaluate the impact of anesthetic flow rate on perioperative inflammation, while the secondary objective was to assess hemodynamic stability during anesthesia. This study may contribute to a better understanding of how low-flow anesthesia influences systemic inflammatory responses and perioperative hemodynamics in morbidly obese patients undergoing bariatric surgery.
Read the detailed description
This retrospective observational cohort study investigated the effects of low-flow and standard-flow sevoflurane anesthesia on perioperative inflammatory markers and hemodynamic stability in patients with obesity undergoing laparoscopic sleeve gastrectomy. The study included 155 adult patients operated between January 2022 and January 2025 at Adana City Training and Research Hospital, Adana, Turkey.
Patients were divided into two groups according to the fresh-gas flow rate used during anesthesia:
Low-flow group: sevoflurane with a total fresh-gas flow rate of 1 L/min,
Standard-flow group: sevoflurane with a total fresh-gas flow rate of 4 L/min.
All patients received general anesthesia as part of routine clinical care. No randomization or intervention was performed by the investigators. Demographic characteristics, anesthesia records, intraoperative hemodynamic parameters (mean arterial pressure, heart rate), and perioperative laboratory results were obtained retrospectively from hospital electronic records.
Preoperative and postoperative (24-hour) values of inflammatory markers-including C-reactive protein (CRP), neutrophil-to-lymphocyte ratio (NLR), and red cell distribution width (RDW)-were compared within and between groups. The primary endpoint was the change in these inflammatory biomarkers between pre- and postoperative measurements. The secondary endpoint was the comparison of intraoperative hemodynamic stability (MAP and HR variability, incidence of hypotension or bradycardia) between the two groups.
This study aims to provide evidence regarding whether low-flow sevoflurane anesthesia (1 L/min) offers comparable or superior inflammatory and hemodynamic profiles compared with standard-flow anesthesia (4 L/min) in morbidly obese patients. The findings may help optimize anesthetic techniques for bariatric surgery by balancing patient safety, hemodynamic stability, and environmental considerations.
- Conditions
- Obesity, Inflammation, Bariatric Surgery Candidate
- Keywords
- Sevoflurane, Low-Flow Anesthesia, Inflammatory Markers, Hemodynamics
- Medical subject headings
- Obesity, Inflammation
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 |
|---|---|---|
| Low-flow Sevoflurane | Patients who underwent laparoscopic sleeve gastrectomy under general anesthesia with low-flow sevoflurane (fresh gas flow = 1 L/min). Data were obtained retrospectively from hospital records. | |
| Standard-flow Sevoflurane | Patients who underwent laparoscopic sleeve gastrectomy under general anesthesia with standard-flow sevoflurane (fresh gas flow = 4 L/min). Data were obtained retrospectively from hospital records. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in C-reactive protein (CRP) concentration
Change in serum C-reactive protein (CRP) levels from preoperative baseline to postoperative 24 hours will be compared between low-flow and standard-flow sevoflurane groups.
Measured: From preoperative baseline to postoperative 24 hours
Change in neutrophil-to-lymphocyte ratio (NLR)
Change in neutrophil-to-lymphocyte ratio (NLR) from preoperative baseline to postoperative 24 hours will be compared between low-flow and standard-flow sevoflurane groups.
Measured: From preoperative baseline to postoperative 24 hours
Change in red cell distribution width (RDW)
Change in red cell distribution width (RDW) from preoperative baseline to postoperative 24 hours will be compared between low-flow and standard-flow sevoflurane groups.
Measured: From preoperative baseline to postoperative 24 hours
Secondary outcomes (2)
Mean arterial pressure (MAP) variability
Change and variability in intraoperative mean arterial pressure (MAP) recorded throughout anesthesia will be compared between low-flow and standard-flow sevoflurane groups.
Measured: From induction of anesthesia to end of anesthesia
Heart rate (HR) variability
Change and variability in intraoperative heart rate (HR) recorded throughout anesthesia will be compared between low-flow and standard-flow sevoflurane groups.
Measured: From induction of anesthesia to end of anesthesia
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Nov 2025
- Study start1 Jan 2022
- Primary completion31 Jan 2025
- Study completion31 Jan 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ObesityStudies 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
- Cohort
- Time perspective
- Retrospective
- Enrolment
- 155 participants (actual)
Sponsor and investigators
- Lead sponsor
- Adana City Training and Research Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Uğur serkan Çitilcioğlu, Adana City Training and Research Hospital
- Investigators
- Ugur serkan Citilcioglu, MD, Principal investigator, Adana City Training and Research Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07230704
- Sponsor's protocol ID
- ADN-LOWFLOW-2025
- Other IDs
- 11-376
- Acronym
- LOWBAR
- Status last verified
- Nov 2025
- First submitted
- 13 Nov 2025
- Last updated
- 27 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: The datasets generated and analyzed during the current study are not publicly available due to institutional data protection policies.
Study at a glance
From the registry record, last updated by the sponsor on 27 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Low-Flow and Standard-Flow Sevoflurane Anesthesia on Perioperative Inflammation in Bariatric Surgery
- ClinicalTrials.gov ID
- NCT07230704
- Acronym / sponsor ID
- LOWBAR / ADN-LOWFLOW-2025
- Conditions
- Obesity, Inflammation, Bariatric Surgery Candidate
- Keywords
- Sevoflurane, Low-Flow Anesthesia, Inflammatory Markers, Hemodynamics
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 155 participants (actual)
- Lead sponsor
- Adana City Training and Research HospitalUniversity, hospital or other
- Study start
- 1 Jan 2022 (actual)
- Primary completion
- 31 Jan 2025 (actual)
- Study completion
- 31 Jan 2025 (actual)
- First posted
- 17 Nov 2025 (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 observational study aimed to compare the effects of low-flow and standard-flow sevoflurane anesthesia on perioperative inflammatory responses in patients undergoing laparoscopic sleeve gastrectomy for obesity. Data were obtained from the anesthesia and laboratory records of 155 adult patients who received either low-flow (1 L/min) or standard-flow (4 L/min) sevoflurane anesthesia between January 2022 and January 2025 at Adana City Training and Research Hospital. Preoperative and postoperative inflammatory markers, including C-reactive protein (CRP), neutrophil-to-lymphocyte ratio (NLR), and red cell distribution width (RDW), were recorded and compared between the two groups. Hemodynamic parameters such as mean arterial pressure and heart rate were also analyzed to assess intraoperative stability. The primary objective of the study was to evaluate the impact of anesthetic flow rate on perioperative inflammation, while the secondary objective was to assess hemodynamic stability during anesthesia. This study may contribute to a better understanding of how low-flow anesthesia influences systemic inflammatory responses and perioperative hemodynamics in morbidly obese patients undergoing bariatric surgery.
Detailed description
This retrospective observational cohort study investigated the effects of low-flow and standard-flow sevoflurane anesthesia on perioperative inflammatory markers and hemodynamic stability in patients with obesity undergoing laparoscopic sleeve gastrectomy. The study included 155 adult patients operated between January 2022 and January 2025 at Adana City Training and Research Hospital, Adana, Turkey.
Patients were divided into two groups according to the fresh-gas flow rate used during anesthesia:
Low-flow group: sevoflurane with a total fresh-gas flow rate of 1 L/min,
Standard-flow group: sevoflurane with a total fresh-gas flow rate of 4 L/min.
All patients received general anesthesia as part of routine clinical care. No randomization or intervention was performed by the investigators. Demographic characteristics, anesthesia records, intraoperative hemodynamic parameters (mean arterial pressure, heart rate), and perioperative laboratory results were obtained retrospectively from hospital electronic records.
Preoperative and postoperative (24-hour) values of inflammatory markers-including C-reactive protein (CRP), neutrophil-to-lymphocyte ratio (NLR), and red cell distribution width (RDW)-were compared within and between groups. The primary endpoint was the change in these inflammatory biomarkers between pre- and postoperative measurements. The secondary endpoint was the comparison of intraoperative hemodynamic stability (MAP and HR variability, incidence of hypotension or bradycardia) between the two groups.
This study aims to provide evidence regarding whether low-flow sevoflurane anesthesia (1 L/min) offers comparable or superior inflammatory and hemodynamic profiles compared with standard-flow anesthesia (4 L/min) in morbidly obese patients. The findings may help optimize anesthetic techniques for bariatric surgery by balancing patient safety, hemodynamic stability, and environmental considerations.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Low-flow Sevoflurane | – | –Patients who underwent laparoscopic sleeve gastrectomy under general anesthesia with low-flow sevoflurane (fresh gas flow = 1 L/min). Data were obtained retrospectively from hospital records. |
| Standard-flow Sevoflurane | – | –Patients who underwent laparoscopic sleeve gastrectomy under general anesthesia with standard-flow sevoflurane (fresh gas flow = 4 L/min). Data were obtained retrospectively from hospital records. |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
- Study population
- Retrospective analysis of 155 adult patients who underwent laparoscopic sleeve gastrectomy under general anesthesia between January 2022 and January 2025 at Adana City Training and Research Hospital. Patients were grouped according to the fresh gas flow rate used during anesthesia (low-flow vs. standard-flow sevoflurane).
Key inclusion criteria (5 listed)
- Adult patients aged 18-60 years
- Underwent laparoscopic sleeve gastrectomy under general anesthesia
- Received low-flow or standard-flow sevoflurane anesthesia
- ASA physical status I-III
- Complete perioperative records available
Key exclusion criteria (5 listed)
- Conversion to open surgery
- Incomplete or missing data
- Significant comorbidities (e.g., severe cardiac, hepatic, or renal dysfunction)
- Perioperative complications unrelated to anesthesia
- Age <18 or >60 years
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
Change in C-reactive protein (CRP) concentration
Time frame: From preoperative baseline to postoperative 24 hours
Change in serum C-reactive protein (CRP) levels from preoperative baseline to postoperative 24 hours will be compared between low-flow and standard-flow sevoflurane groups.
Change in neutrophil-to-lymphocyte ratio (NLR)
Time frame: From preoperative baseline to postoperative 24 hours
Change in neutrophil-to-lymphocyte ratio (NLR) from preoperative baseline to postoperative 24 hours will be compared between low-flow and standard-flow sevoflurane groups.
Change in red cell distribution width (RDW)
Time frame: From preoperative baseline to postoperative 24 hours
Change in red cell distribution width (RDW) from preoperative baseline to postoperative 24 hours will be compared between low-flow and standard-flow sevoflurane groups.
2 secondary outcomes
Mean arterial pressure (MAP) variability
Time frame: From induction of anesthesia to end of anesthesia
Heart rate (HR) variability
Time frame: From induction of anesthesia to end of anesthesia
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 27 Aug 2026.
- Individual participant dataSharing planned: No. The datasets generated and analyzed during the current study are not publicly available due to institutional data protection policies.
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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.
Ugur serkan Citilcioglu, MD principal investigator
Adana City Training and Research Hospital
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 Obesity and Inflammation, run by Adana City Training and Research Hospital 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 5 inclusion and 5 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 27 Aug 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?
Change in C-reactive protein (CRP) concentration (time frame: From preoperative baseline to postoperative 24 hours). The study lists 3 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 27 Aug 2026.