Major Abdominal SurgeriesNCT07212543
Low-Flow Desflurane Anesthesia and Its Effects on BIS and Postoperative Cognitive Functions
An observational study of Major Abdominal Surgeries, run by Dolunay ARIK at 1 site in Turkey (Türkiye).
Trial summary
This study investigates the effects of low-flow desflurane anesthesia in adult patients undergoing major abdominal surgery. The researchers will examine whether different low-flow strategies: Cause differences in the Bispectral Index (BIS), which measures brain activity during anesthesia, Affect postoperative… Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Major Abdominal Surgeries
- How many people
- 72 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 15 May 2025to 21 Dec 2025
- 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 75 years
- All sexes
- Adult, Older adult
Study population: The study population will be recruited from patients undergoing elective major abdominal surgery at the Department of Anesthesiology and Reanimation, Ankara Dr Abdurrahman Yurtaslan Onkology Training and Research Hospital.
Who may be able to join
- Patients aged 18-75 years
- ASA physical status I-III
- Scheduled for elective major abdominal surgery
- Provided written informed consent
- Normal preoperative neurocognitive function
Who cannot join
- History of neurological or psychiatric disorders
- History of cognitive impairment
- Diagnosed hepatic or renal insufficiency
- Presence of other systemic diseases contraindicating anesthesia
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Dr. Abdurrahman Yurtaslan Oncology Training and Research Hospital
Ankara, YENİMAHALLE, 06200
About this study
Official title: The Effects of Different Low-Flow Desflurane Anesthesia Strategies on Bispectral Index and Postoperative Cognitive Functions in Patients Undergoing Major Abdominal Surgery
This study investigates the effects of low-flow desflurane anesthesia in adult patients undergoing major abdominal surgery. The researchers will examine whether different low-flow strategies:
Cause differences in the Bispectral Index (BIS), which measures brain activity during anesthesia, Affect postoperative cognitive functions such as memory and attention.
Read more
Participants will:
Receive desflurane anesthesia during surgery, Have anesthesia delivered at different low-flow rates, Have their BIS values monitored throughout the operation, Complete tests after surgery to evaluate their cognitive functions.
This research will help determine the safety of different low-flow strategies and their impact on patients' cognitive recovery after surgery.
Read the detailed description
This prospective observational study is designed to evaluate the effects of different low-flow desflurane anesthesia strategies on intraoperative anesthetic depth, measured by the Bispectral Index (BIS), and on postoperative cognitive functions in patients undergoing major abdominal surgery.
Patients will receive desflurane anesthesia delivered at different low-flow rates. Throughout surgery, BIS values will be continuously monitored to assess the depth of anesthesia. Postoperatively, standardized cognitive function tests will be performed at predetermined time points to evaluate potential cognitive impairment or recovery. The study aims to clarify whether the choice of low-flow strategy influences short-term postoperative neurocognitive outcomes.
Quality assurance and data management procedures:
Data collection will be conducted using standardized electronic case report forms (eCRFs).
All collected data will undergo range and consistency checks against predefined rules.
Source data verification will be performed through comparison with medical records and anesthetic monitoring logs.
A data dictionary will be maintained, documenting each variable, coding standards (e.g., MedDRA where applicable), and reference ranges.
Missing data will be handled according to a predefined plan, with cases flagged as missing, unusable, or inconsistent.
Sample size and statistical plan:
The sample size has been estimated to ensure sufficient statistical power to detect clinically meaningful differences in BIS and postoperative cognitive function scores between different low-flow strategies. Statistical analyses will include descriptive statistics, group comparisons using parametric or non-parametric tests, and regression models where appropriate. A detailed statistical analysis plan has been developed to address both primary and secondary endpoints.
This study will provide evidence regarding the safety and neurocognitive impact of different low-flow desflurane strategies. Findings are expected to support clinical decision-making in optimizing anesthetic management for patients undergoing major abdominal procedures.
- Conditions
- Major Abdominal Surgeries
- Being tested
- Routine anesthesia care (desflurane at different low-flow rates: 0.5, 1.0, 1.5 L/min); no intervention assigned as part of the study.
- Keywords
- Low-flow anesthesia., Desflurane, Major abdominal surgery, Bispectral Index (BIS)
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Routine anesthesia care (desflurane at different low-flow rates: 0.5, 1.0, 1.5 L/min); no intervention assigned as part of the study.Other
Routine anesthesia care (desflurane at different low-flow rates: 0.5, 1.0, 1.5 L/min); no intervention assigned as part of the study.
| Study group | Role | What they receive |
|---|---|---|
| Group 1 :desflurane 0.5 L/min Group 2 :desflurane 1 L/min Group 3 : desflurane 1.5 L/min | This cohort includes adult patients undergoing major abdominal surgery whose general anesthesia is maintained with desflurane using different low-flow strategies. The main intervention of interest is the variation in fresh gas flow rates. Participants will be divided into three subgroups according to the applied flow rate:
0.5 L/min desflurane anesthesia 1.0 L/min desflurane anesthesia 1.5 L/min desflurane anesthesia During surgery, the depth of anesthesia will be continuously monitored using the Bispectral Index (BIS). Cognitive function will be assessed both preoperatively and postoperatively with the Mini-Mental State Examination (MMSE). This design will allow comparison of the effects of different low-flow strategies on intraoperative BIS values as well as on cognitive function changes before and after surgery. Receives: Other: Routine anesthesia care (desflurane at different low-flow rates: 0.5, 1.0, 1.5 L/min); no intervention assigned as part of the study. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change from Baseline in Mini-Mental State Examination (MMSE) Score Postoperatively
Measure: Change in cognitive function assessed by the Mini-Mental State Examination (MMSE)
Time Frame: From baseline (preoperative assessment) to postoperative assessment (within 24 hours after surgery)
Description: The MMSE will be used to evaluate changes in cognitive function in patients receiving desflurane anesthesia at different low-flow rates. The primary endpoint is the difference between preoperative and postoperative MMSE scores.
Measured: From baseline (preoperative assessment, within 24 hours before surgery) to postoperative assessments at 24 hours and 7 days after surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Oct 2025
- Study start15 May 2025
- Primary completion20 Dec 2025 (estimated)
- Study completion21 Dec 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Major Abdominal SurgeriesStudies 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
- Prospective
- Enrolment
- 72 participants (actual)
Sponsor and investigators
- Lead sponsor
- Dolunay ARIK
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Dolunay ARIK, Dr Abdurrahman Yurtaslan Ankara Oncology Training and Research Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07212543
- Sponsor's protocol ID
- 2025-05/73
- Status last verified
- Oct 2025
- First submitted
- 1 Oct 2025
- Last updated
- 9 Dec 2025
- Results posted
- No
- Individual data sharing
- Undecided
Publications
Bingol Tanriverdi T, Tercan M, Gusun Halitoglu A, Kaya A, Patmano G. Comparison of the Effects of Low-flow and Normal-flow Desflurane Anaesthesia on Inflammatory Parameters in Patients Undergoing Laparoscopic Cholecystectomy. Turk J Anaesthesiol Reanim. 2021 Feb;49(1):18-24. doi: 10.5152/TJAR.2020.30. Epub 2020 Nov 30.
PubMed 33718901https://www.researchgate.net/publication/319617159_Low_flow_anesthesia_will_gain_eras_enhanced_recovery_after_surgery
Baum JA. Low-flow anesthesia: theory, practice, technical preconditions, advantages, and foreign gas accumulation. J Anesth. 1999;13(3):166-74. doi: 10.1007/s005400050050. No abstract available.
PubMed 14530937
Study at a glance
From the registry record, last updated by the sponsor on 9 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effects of Different Low-Flow Desflurane Anesthesia Strategies on Bispectral Index and Postoperative Cognitive Functions in Patients Undergoing Major Abdominal Surgery
- ClinicalTrials.gov ID
- NCT07212543
- Acronym / sponsor ID
- 2025-05/73
- Conditions
- Major Abdominal Surgeries
- Keywords
- Low-flow anesthesia., Desflurane, Major abdominal surgery, Bispectral Index (BIS)
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 72 participants (actual)
- Lead sponsor
- Dolunay ARIKUniversity, hospital or other
- Study start
- 15 May 2025 (actual)
- Primary completion
- 20 Dec 2025 (estimated)
- Study completion
- 21 Dec 2025 (estimated)
- First posted
- 8 Oct 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 study investigates the effects of low-flow desflurane anesthesia in adult patients undergoing major abdominal surgery. The researchers will examine whether different low-flow strategies:
Cause differences in the Bispectral Index (BIS), which measures brain activity during anesthesia, Affect postoperative cognitive functions such as memory and attention.
Participants will:
Receive desflurane anesthesia during surgery, Have anesthesia delivered at different low-flow rates, Have their BIS values monitored throughout the operation, Complete tests after surgery to evaluate their cognitive functions.
This research will help determine the safety of different low-flow strategies and their impact on patients' cognitive recovery after surgery.
Detailed description
This prospective observational study is designed to evaluate the effects of different low-flow desflurane anesthesia strategies on intraoperative anesthetic depth, measured by the Bispectral Index (BIS), and on postoperative cognitive functions in patients undergoing major abdominal surgery.
Patients will receive desflurane anesthesia delivered at different low-flow rates. Throughout surgery, BIS values will be continuously monitored to assess the depth of anesthesia. Postoperatively, standardized cognitive function tests will be performed at predetermined time points to evaluate potential cognitive impairment or recovery. The study aims to clarify whether the choice of low-flow strategy influences short-term postoperative neurocognitive outcomes.
Quality assurance and data management procedures:
Data collection will be conducted using standardized electronic case report forms (eCRFs).
All collected data will undergo range and consistency checks against predefined rules.
Source data verification will be performed through comparison with medical records and anesthetic monitoring logs.
A data dictionary will be maintained, documenting each variable, coding standards (e.g., MedDRA where applicable), and reference ranges.
Missing data will be handled according to a predefined plan, with cases flagged as missing, unusable, or inconsistent.
Sample size and statistical plan:
The sample size has been estimated to ensure sufficient statistical power to detect clinically meaningful differences in BIS and postoperative cognitive function scores between different low-flow strategies. Statistical analyses will include descriptive statistics, group comparisons using parametric or non-parametric tests, and regression models where appropriate. A detailed statistical analysis plan has been developed to address both primary and secondary endpoints.
This study will provide evidence regarding the safety and neurocognitive impact of different low-flow desflurane strategies. Findings are expected to support clinical decision-making in optimizing anesthetic management for patients undergoing major abdominal procedures.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Group 1 :desflurane 0.5 L/min Group 2 :desflurane 1 L/min Group 3 : desflurane 1.5 L/min | – | Other: Routine anesthesia care (desflurane at different low-flow rates: 0.5, 1.0, 1.5 L/min); no intervention assigned as part of the study.This cohort includes adult patients undergoing major abdominal surgery whose general anesthesia is maintained with desflurane using different low-flow strategies. The main intervention of interest is the variation in fresh gas flow rates. Participants will be divided into three subgroups according to the applied flow rate: 0.5 L/min desflurane anesthesia 1.0 L/min desflurane anesthesia 1.5 L/min desflurane anesthesia During surgery, the depth of anesthesia will be continuously monitored using the Bispectral Index (BIS). Cognitive function will be assessed both preoperatively and postoperatively with the Mini-Mental State Examination (MMSE). This design will allow comparison of the effects of different low-flow strategies on intraoperative BIS values as well as on cognitive function changes before and after surgery. |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Age groups
- Adult, Older adult
- Study population
- The study population will be recruited from patients undergoing elective major abdominal surgery at the Department of Anesthesiology and Reanimation, Ankara Dr Abdurrahman Yurtaslan Onkology Training and Research Hospital.
Key inclusion criteria (5 listed)
- Patients aged 18-75 years
- ASA physical status I-III
- Scheduled for elective major abdominal surgery
- Provided written informed consent
- Normal preoperative neurocognitive function
Key exclusion criteria (4 listed)
- History of neurological or psychiatric disorders
- History of cognitive impairment
- Diagnosed hepatic or renal insufficiency
- Presence of other systemic diseases contraindicating anesthesia
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Routine anesthesia care (desflurane at different low-flow rates: 0.5, 1.0, 1.5 L/min); no intervention assigned as part of the study.Routine anesthesia care (desflurane at different low-flow rates: 0.5, 1.0, 1.5 L/min); no intervention assigned as part of the study. | Other | Group 1 :desflurane 0.5 L/min Group 2 :desflurane 1 L/min Group 3 : desflurane 1.5 L/min |
Primary outcome
Change from Baseline in Mini-Mental State Examination (MMSE) Score Postoperatively
Time frame: From baseline (preoperative assessment, within 24 hours before surgery) to postoperative assessments at 24 hours and 7 days after surgery
Measure: Change in cognitive function assessed by the Mini-Mental State Examination (MMSE) Time Frame: From baseline (preoperative assessment) to postoperative assessment (within 24 hours after surgery) Description: The MMSE will be used to evaluate changes in cognitive function in patients receiving desflurane anesthesia at different low-flow rates. The primary endpoint is the difference between preoperative and postoperative MMSE scores.
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 9 Dec 2025.
- Background: PubMed 33718901Bingol Tanriverdi T, Tercan M, Gusun Halitoglu A, Kaya A, Patmano G. Comparison of the Effects of Low-flow and Normal-flow Desflurane Anaesthesia on Inflammatory Parameters in Patients Undergoing Laparoscopic Cholecystectomy. Turk J Anaesthesiol Reanim. 2021 Feb;49(1):18-24. doi: 10.5152/TJAR.2020.30. Epub 2020 Nov 30.
- Backgroundhttps://www.researchgate.net/publication/319617159_Low_flow_anesthesia_will_gain_eras_enhanced_recovery_after_surgery
- Background: PubMed 14530937Baum JA. Low-flow anesthesia: theory, practice, technical preconditions, advantages, and foreign gas accumulation. J Anesth. 1999;13(3):166-74. doi: 10.1007/s005400050050. No abstract available.
- Dr. Abdurrahman Yurtaslan Oncology Training and Research Hospital mail adressLink provided by the sponsor.
- Related InfoLink provided by the sponsor.
- Individual participant dataSharing planned: Undecided
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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.
The record lists no contact. Use the official record to reach the sponsor.
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 Major Abdominal Surgeries, run by Dolunay ARIK 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 4 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: under way, not looking for participants, as of the sponsor's last update on 9 Dec 2025. 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?
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 from Baseline in Mini-Mental State Examination (MMSE) Score Postoperatively (time frame: From baseline (preoperative assessment, within 24 hours before surgery) to postoperative assessments at 24 hours and 7 days after surgery). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07212543, which also lists 3 linked publications.
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 9 Dec 2025.