Comparison of Total Oxidant and Total Antioxidant Capacities in Low-Flow and High-Flow General Anesthesia

An observational study of Oxidative Stress and Anesthesia, run by Duzce University at 1 site in Turkey (Türkiye).

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Trial summary

The goal of this observational study is to determine whether low-flow anesthesia has a positive contribution to the total oxidant/antioxidant balance. Read more about this study

Who is it for?: Ages 18 to 60 yearsHealthy volunteers can take part
Conditions the study is for: Oxidative Stress, Anesthesia
What is being tested?: general anesthesia
How many people: 72 participants
Where: 1 siteTurkey (Türkiye)
Study dates: 1 Aug 2022to 1 Nov 2023
Phase: Observational
Are there results?: Yes, posted in the registrySummary in the doctors' view

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
Healthy volunteers accepted
Adult

Study population: 72 patients who meet the inclusion criteria and sign informed consent will be included.

Who may be able to join

Patients older than 18 years and younger than 60 years of age who will be operated under general anesthesia
Patients in I, II risk groups according to the American Society of Anesthesiologists (ASA) classification

Who cannot join

ASA III and above patients,
Patients for whom Intensive Care Unit (ICU) indication is required
Chronic obstructive pulmonary disease,
Personal or family history of malignant hyperthermia,
Morbid obesity,
Alcohol or drug dependency,

Show all 10Show fewer

Having a history of liver or kidney disease,
Having coronary artery disease or heart failure,
Having significant anemia or hemoglobinopathy,
Hypotension, hypovolemia, sepsis.

Trial locations and contacts

1 site in 1 country.

Turkey (Türkiye)1 site

Duzce University Faculty of Medicine
Düzce, Düzce, 81000

Other trials in Turkey (Türkiye)

About this study

Official title: Comparison of Changes in Total Oxidant and Total Antioxidant Capacities in Low-Flow and High-Flow General Anesthesia Protocols

The goal of this observational study is to determine whether low-flow anesthesia has a positive contribution to the total oxidant/antioxidant balance.

Read the detailed description

General anesthesia is a complex physiological state characterized by reversible loss of consciousness, whole-body analgesia, amnesia, and muscle relaxation. Modern anesthesia devices used for patients under general anesthesia are semi-closed rebreathing systems. The fresh gas flow entering these closed systems is determined by the anesthetists.

The term low-flow anesthesia is used to describe inhalation anesthesia techniques that are administered with a semi-closed rebreathing system and have a rebreathing rate of at least 50%. The high standard of anesthesia machines, the existence of monitors that analyze the anesthetic gas composition continuously and in detail, and the increase in knowledge about the pharmacodynamics and pharmacokinetics of inhalation anesthetics have greatly facilitated the safe administration of low-flow anesthesia. The terminology associated with low-flow anesthesia techniques may be based on rebreathing rate or fresh gas flow rate. The most important factor determining the rebreathing rate is the fresh gas flow rate. If the fresh gas flow rate is reduced to less than 2 L/min when using modern rebreathing systems, low-flow anesthesia can be mentioned for most patients.

Oxidative stress is accepted as a pathological mechanism. Oxidative stress is a state of oxidative damage that occurs when the critical balance between free radical production and antioxidant defense systems is disrupted. Oxidative stress is beneficial in certain physiological conditions. For example, it can strengthen biological defense mechanisms during appropriate physical exercise and ischemia. However, its benefits are limited to these specific situations, and in many other cases, high levels of oxidative stress cause cell death and thus cell and tissue damage via necrotic or apoptotic mechanisms. If damage continues at the cell and tissue level, it causes the onset and progression of various organ damage and diseases.

Aim: In low-flow anesthesia applications, the amount of inspired oxygen is expected to be low due to keeping the gas supplied to the system low. Therefore, in this study, it will be investigated whether low-flow anesthesia has a positive contribution to the total oxidant/antioxidant balance.

Method: A total of 72 patients undergoing general anesthesia who meet the inclusion criteria and signed informed consent will be included in the study. Vitamin D, albumin, C-reactive protein (CRP), Total Antioxidant (TAS) and Total Oxidant (TOS) levels will be determined in the blood samples taken from all volunteers routinely before the operation. Basal peak heart rate (HR), peripheral oxygen saturation (SpO2), systolic (SBP) and diastolic blood pressure (DBP), end-tidal carbon dioxide (ETCO2), body temperature and processed EEG values will be recorded. All measurements will be recorded and repeated at 5 minute intervals throughout the operation. Volunteers will be randomly divided into 2 groups as low flow group (D) and high flow group (Y). Fresh gas flow of 1 L/min to D group and 4 L/min to Y group will be administered. During the operation, the processed EEG values of all patients will be held between 40-60 and it will be ensured that they are at the same anesthesia depth. Albumin, CRP, TAS and TOS values will be checked again in the blood samples taken for routine tests performed at the end of operation and postoperatively within 6-24 hours after the end of operation, and these values will be compared with the values obtained before the operation.

Statistical Analysis: It is planned to use 'Independent Samples t test' or 'Mann-Whitney U test' in comparison of the groups, depending on the distribution of the data. Chi-square tests will be used to examine the relationships between categorical variables. 'Repeated Measure ANOVA' will be used in the evaluation of repeated measurements. Correlations between continuous variables will be analyzed by Pearson or Spearman correlation analysis, depending on the distribution of the data.

Conditions: Oxidative Stress, Anesthesia
Being tested: general anesthesia
Keywords: Oxidative stress, Anesthesia, General, Low flow anesthesia

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

general anesthesiaOther
All patients will undergo general anesthesia. Group D will receive fresh gas flow of 1 l/min and Group Y will receive fresh gas flow of 4 l/min.

Study groups in NCT05590312
Study group	Role	What they receive
Low Flow Group - Group D		Vitamin D, Albumin, CRP, TAS and TOS values will be checked before and during the operation in 36 patients who will receive general anesthesia. Flow of 1 L/min will be given during the operation. The processed EEG values of all patients will be monitored and they will be ensured to be at the same anesthesia depth. Albumin, CRP, TAS and TOS values will be checked again from the blood taken postoperatively in the patients who were taken to the service after the operation and these values will be compared with the previous ones. Receives: Other: general anesthesia
High Flow Group - Group Y		Vitamin D, Albumin, CRP, TAS and TOS values will be checked before and during the operation in 36 patients who will receive general anesthesia. Flow of 4 L/min will be given during the operation. The processed EEG values of all patients will be monitored and they will be ensured to be at the same anesthesia depth. Albumin, CRP, TAS and TOS values will be checked again from the blood taken postoperatively in the patients who were taken to the service after the operation and these values will be compared with the previous ones. Receives: Other: general anesthesia

What is being measured

The primary outcome is the main question the study is designed to answer.

Comparison of Total Antioxidant Status (TAS) Levels Between the Two Groups
Vitamin D, Albumin, CRP, TAS and TOS values will be checked before the operation in 72 patients who will receive general anesthesia in both groups. Albumin, CRP, TAS and TOS values will be checked again from the blood taken postoperatively in the patients who were taken to the ward after the operation and these values will be compared between two groups and with the previous level in the same group.
Measured: 3 times in 24 hours perioperatively. TAS/TOS levels will be determined before the operation, at the end of operation and at 6th hour after the end of operation.
Change From Baseline in Total Oxidant Status (TOS) Levels
Vitamin D, Albumin, CRP, TAS and TOS values will be checked before the operation in 72 patients who will receive general anesthesia in both groups. Albumin, CRP, TAS and TOS values will be checked again from the blood taken postoperatively in the patients who were taken to the ward after the operation and these values will be compared between two groups and with the previous level in the same group.
Measured: 3 times in 24 hours perioperatively. TAS/TOS levels will be determined before the operation, at the end of operation and at 6th hour after the end of operation.
Change From Baseline in Albumin Levels.
Vitamin D, Albumin, CRP, TAS and TOS values will be checked before the operation in 72 patients who will receive general anesthesia in both groups. Albumin, CRP, TAS and TOS values will be checked again from the blood taken postoperatively in the patients who were taken to the ward after the operation and these values will be compared between two groups and with the previous level in the same group.
Measured: 3 times in 24 hours perioperatively. Albumin levels will be determined before the operation, at the end of operation and at 6th hour after the end of operation.
Change From Baseline in C Reactive Protein (CRP) Levels.
Vitamin D, Albumin, CRP, TAS and TOS values will be checked before the operation in 72 patients who will receive general anesthesia in both groups. Albumin, CRP, TAS and TOS values will be checked again from the blood taken postoperatively in the patients who were taken to the ward after the operation and these values will be compared between two groups and with the previous level in the same group.
Measured: 3 times in 24 hours perioperatively. Albumin levels will be determined before the operation, at the end of operation and at 6th hour after the end of operation.
Comparison of Vitamin D Levels Between the Two Groups
Vitamin D, Albumin, CRP, TAS and TOS values will be checked before the operation in 72 patients who will receive general anesthesia in both groups. Albumin, CRP, TAS and TOS values will be checked again from the blood taken postoperatively in the patients who were taken to the ward after the operation and these values will be compared between two groups and with the previous level in the same group.
Measured: 1 time before the operation.

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

1 Aug 20221 Nov 2023

First posted21 Oct 2022
Study start1 Aug 2022
Primary completion1 Nov 2023
Study completion1 Nov 2023

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Other trials for Oxidative StressStudies 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)

IDs, dates and publications

ClinicalTrials.gov ID: NCT05590312
Sponsor's protocol ID: drozlemersoy3
Status last verified: Jan 2025
First submitted: 18 Oct 2022
Last updated: 17 Jan 2025
Results posted: Yes, on ClinicalTrials.gov
FDA-regulated drug: No
FDA-regulated device: No
Individual data sharing: No

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

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Study at a glance

From the registry record, last updated by the sponsor on 17 Jan 2025. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Comparison of Changes in Total Oxidant and Total Antioxidant Capacities in Low-Flow and High-Flow General Anesthesia Protocols
ClinicalTrials.gov ID: NCT05590312
Acronym / sponsor ID: drozlemersoy3
Conditions: Oxidative Stress, Anesthesia
Keywords: Oxidative stress, Anesthesia, General, Low flow anesthesia
Study type: Observational
Recruitment status: Completed
Enrolment: 72 participants (actual)
Lead sponsor: Duzce UniversityUniversity, hospital or other
Study start: 1 Aug 2022 (actual)
Primary completion: 1 Nov 2023 (actual)
Study completion: 1 Nov 2023 (actual)
First posted: 21 Oct 2022 (actual)
Results: Posted 17 Jan 2025

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

The goal of this observational study is to determine whether low-flow anesthesia has a positive contribution to the total oxidant/antioxidant balance.

Detailed description

Study design

Observational model: Cohort
Time perspective: Prospective
Number of arms: 2

Arm	Type	Receives
Low Flow Group - Group D	–	Other: general anesthesiaVitamin D, Albumin, CRP, TAS and TOS values will be checked before and during the operation in 36 patients who will receive general anesthesia. Flow of 1 L/min will be given during the operation. The processed EEG values of all patients will be monitored and they will be ensured to be at the same anesthesia depth. Albumin, CRP, TAS and TOS values will be checked again from the blood taken postoperatively in the patients who were taken to the service after the operation and these values will be compared with the previous ones.
High Flow Group - Group Y	–	Other: general anesthesiaVitamin D, Albumin, CRP, TAS and TOS values will be checked before and during the operation in 36 patients who will receive general anesthesia. Flow of 4 L/min will be given during the operation. The processed EEG values of all patients will be monitored and they will be ensured to be at the same anesthesia depth. Albumin, CRP, TAS and TOS values will be checked again from the blood taken postoperatively in the patients who were taken to the service after the operation and these values will be compared with the previous ones.

Who may qualify

Ages: 18 to 60 years
Sex: All
Healthy volunteers: Accepted
Age groups: Adult
Study population: 72 patients who meet the inclusion criteria and sign informed consent will be included.

Key inclusion criteria (2 listed)

Patients older than 18 years and younger than 60 years of age who will be operated under general anesthesia
Patients in I, II risk groups according to the American Society of Anesthesiologists (ASA) classification

Key exclusion criteria (10 listed)

ASA III and above patients,
Patients for whom Intensive Care Unit (ICU) indication is required
Chronic obstructive pulmonary disease,
Personal or family history of malignant hyperthermia,
Morbid obesity,

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
general anesthesiaAll patients will undergo general anesthesia. Group D will receive fresh gas flow of 1 l/min and Group Y will receive fresh gas flow of 4 l/min.	Other	High Flow Group - Group Y, Low Flow Group - Group D

Primary outcome

Comparison of Total Antioxidant Status (TAS) Levels Between the Two Groups
Time frame: 3 times in 24 hours perioperatively. TAS/TOS levels will be determined before the operation, at the end of operation and at 6th hour after the end of operation.
Vitamin D, Albumin, CRP, TAS and TOS values will be checked before the operation in 72 patients who will receive general anesthesia in both groups. Albumin, CRP, TAS and TOS values will be checked again from the blood taken postoperatively in the patients who were taken to the ward after the operation and these values will be compared between two groups and with the previous level in the same group.
Change From Baseline in Total Oxidant Status (TOS) Levels
Time frame: 3 times in 24 hours perioperatively. TAS/TOS levels will be determined before the operation, at the end of operation and at 6th hour after the end of operation.
Vitamin D, Albumin, CRP, TAS and TOS values will be checked before the operation in 72 patients who will receive general anesthesia in both groups. Albumin, CRP, TAS and TOS values will be checked again from the blood taken postoperatively in the patients who were taken to the ward after the operation and these values will be compared between two groups and with the previous level in the same group.
Change From Baseline in Albumin Levels.
Time frame: 3 times in 24 hours perioperatively. Albumin levels will be determined before the operation, at the end of operation and at 6th hour after the end of operation.
Vitamin D, Albumin, CRP, TAS and TOS values will be checked before the operation in 72 patients who will receive general anesthesia in both groups. Albumin, CRP, TAS and TOS values will be checked again from the blood taken postoperatively in the patients who were taken to the ward after the operation and these values will be compared between two groups and with the previous level in the same group.
Change From Baseline in C Reactive Protein (CRP) Levels.
Time frame: 3 times in 24 hours perioperatively. Albumin levels will be determined before the operation, at the end of operation and at 6th hour after the end of operation.
Vitamin D, Albumin, CRP, TAS and TOS values will be checked before the operation in 72 patients who will receive general anesthesia in both groups. Albumin, CRP, TAS and TOS values will be checked again from the blood taken postoperatively in the patients who were taken to the ward after the operation and these values will be compared between two groups and with the previous level in the same group.
Comparison of Vitamin D Levels Between the Two Groups
Time frame: 1 time before the operation.
Vitamin D, Albumin, CRP, TAS and TOS values will be checked before the operation in 72 patients who will receive general anesthesia in both groups. Albumin, CRP, TAS and TOS values will be checked again from the blood taken postoperatively in the patients who were taken to the ward after the operation and these values will be compared between two groups and with the previous level in the same group.

Results and safety

Results posted to the registry on 17 Jan 2025, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Low Flow Group - Group D	36	36
High Flow Group - Group Y	36	36

Primary outcome: Comparison of Total Antioxidant Status (TAS) Levels Between the Two Groups

Time frame: 3 times in 24 hours perioperatively. TAS/TOS levels will be determined before the operation, at the end of operation and at 6th hour after the end of operation.. Mean (Standard Deviation). Unit: mmol Eq / L

Measure	Low Flow Group - Group D n = 36	High Flow Group - Group Y n = 36
T0: Before the operation	1.76 (0.23)	1.82 (0.3)
T1: At the end of the operation	1.83 (0.24)	1.92 (0.27)
T2: At 6th hour after the end of the operation	1.85 (0.28)	1.89 (0.29)

Primary outcome: Change From Baseline in Total Oxidant Status (TOS) Levels

Measure	Low Flow Group - Group D n = 36	High Flow Group - Group Y n = 36
T0: before the operation	19.82 (11.82)	21.48 (11.01)
T1: at the end of operation	19.66 (11.75)	17.20 (8.72)
T2: at 6th hour after the end of operation.	22.49 (11.99)	21.38 (11.64)

Primary outcome: Change From Baseline in Albumin Levels.

Time frame: 3 times in 24 hours perioperatively. Albumin levels will be determined before the operation, at the end of operation and at 6th hour after the end of operation.. Mean (Standard Deviation). Unit: mg/dL

Measure	Low Flow Group - Group D n = 36	High Flow Group - Group Y n = 36
T0: before the operation	4.24 (0.3)	4.15 (0.24)
T1: at the end of operation	4.05 (0.38)	4.02 (0.39)
T2: at 6th hour after the end of operation.	3.96 (0.36)	3.97 (0.40)

Primary outcome: Change From Baseline in C Reactive Protein (CRP) Levels.

Measure	Low Flow Group - Group D n = 36	High Flow Group - Group Y n = 36
T0: before the operation	0.30 (0.54)	0.53 (1.61)
T1: at the end of operation	0.31 (0.56)	0.52 (1.36)
T2: at 6th hour after the end of operation.	1.41 (2.58)	1.37 (2.31)

Adverse events

Time frame: 2 days: operation day and postoperative 6 hours ( postoperative 1st day). Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Low Flow Group - Group D	0 of 36 (0%)	0 of 36 (0%)	0 of 36
High Flow Group - Group Y	0 of 36 (0%)	0 of 36 (0%)	0 of 36

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 17 Jan 2025.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Individual participant dataSharing planned: No

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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.

Özlem Ersoy Karka principal investigator

Düzce University Faculty of Medicine

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 Oxidative Stress and Anesthesia, run by Duzce 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 2 inclusion and 10 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 17 Jan 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?

Yes. Results are posted in the registry (first posted 17 Jan 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

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?

Comparison of Total Antioxidant Status (TAS) Levels Between the Two Groups (time frame: 3 times in 24 hours perioperatively. TAS/TOS levels will be determined before the operation, at the end of operation and at 6th hour after the end of operation.). The study lists 5 primary outcomes in all. 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 NCT05590312.

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 17 Jan 2025; AzTrials last refreshed its copy on 8 Nov 2026.