General AnesthesiaNCT07197567
Equivalent MAC in General Anesthesia
An observational study of General Anesthesia and Intraoperative Monitoring, run by Sakarya University at 1 site in Turkey (Türkiye).
Trial summary
This observational study aims to evaluate the clinical applicability of the Equivalent Minimum Alveolar Concentration (eMAC) parameter during general anesthesia. eMAC is a recently developed index that combines the effects of both inhalational and intravenous anesthetics, providing a unified measure of anesthetic… Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- General Anesthesia, Intraoperative Monitoring, Anesthetic Depth
- What is being tested?
- Sevoflurane + Remifentanil and Sevoflurane + Propofol + Remifentanil
- Type of treatment
- Injection or infusion
- How many people
- 60 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Nov 2025to 15 Jan 2026
- 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 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Adult patients scheduled for elective surgical procedures under general anesthesia at Sakarya University Training and Research Hospital, Department of Anesthesiology and Reanimation, will be considered for enrollment. Patients represent a typical surgical population with ASA physical status I-III.
Who may be able to join
- Adults aged 18-65 years
- Scheduled for elective surgery under general anesthesia
- American Society of Anesthesiologists (ASA) Physical Status I-III
- Feasibility of Bispectral Index (BIS) monitoring
- Provision of written informed consent
Who cannot join
- History of neurological disease (e.g., epilepsy, dementia, severe brain injury)
- Known allergy to anesthetic agents
- Severe cardiovascular or respiratory failure
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Sakarya University Training and Research Hospital, Department of Anesthesiology and Reanimation
Sakarya, Adapazari
About this study
Official title: Evaluation of Equivalent Minimum Alveolar Concentration During General Anesthesia: An Observational Study
This observational study aims to evaluate the clinical applicability of the Equivalent Minimum Alveolar Concentration (eMAC) parameter during general anesthesia. eMAC is a recently developed index that combines the effects of both inhalational and intravenous anesthetics, providing a unified measure of anesthetic depth. While the traditional Minimum Alveolar Concentration (MAC) is widely used for inhalational agents, it does not reflect intravenous anesthetics or combined techniques such as Combined Intravenous and Inhalational Anesthesia (CIVIA).
In this study, adult patients undergoing elective surgery under general anesthesia will be observed. Standard clinical practice will not be altered. Demographic and clinical parameters, including eMAC, MAC, Bispectral Index (BIS), and hemodynamic variables, will be recorded at defined perioperative time points. No experimental drugs or additional procedures will be administered.
Read more
The primary aim is to investigate the correlation between eMAC and MAC values obtained during anesthesia. Secondary objectives include assessing the relationship between eMAC and BIS values, comparing eMAC, MAC, and BIS across different anesthetic techniques, and evaluating hemodynamic stability in relation to anesthetic depth.
The results of this study may contribute to a better understanding of eMAC and its potential role in clinical anesthesia practice.
Read the detailed description
This is a prospective, observational study designed to evaluate the Equivalent Minimum Alveolar Concentration (eMAC) parameter during general anesthesia. eMAC is a composite index that incorporates the anesthetic effects of both inhalational agents and intravenous anesthetics, such as propofol and remifentanil, allowing assessment of anesthetic depth under combined techniques (CIVIA). While the traditional Minimum Alveolar Concentration (MAC) is well established for inhalational agents, its applicability is limited in cases where intravenous agents are administered. eMAC has been proposed as a more comprehensive measure, but clinical validation is lacking.
Adult patients (ages 18-65, ASA I-III) scheduled for elective surgical procedures under general anesthesia will be enrolled. No experimental interventions will be performed; anesthetic management will follow routine clinical practice. Participants will be observed in two groups, based on the anesthetic technique selected by the attending anesthesiologist.
Data collection will include demographic and baseline clinical variables, as well as anesthetic depth parameters (eMAC, MAC, Bispectral Index [BIS]) and hemodynamic variables (heart rate, mean arterial pressure, SpO₂). Measurements will be recorded at predefined time points: prior to induction (T0), 5 minutes after induction (T1), at the beginning of surgery (T2), at the midpoint of surgery (T3), and at the end of surgery (T4).
The primary outcome measure is the correlation between eMAC and MAC values obtained during anesthesia. Secondary outcome measures include the correlation between eMAC and BIS values, comparisons of eMAC, MAC, and BIS among different anesthetic techniques, and evaluation of hemodynamic stability in relation to anesthetic depth.
Statistical analysis will be performed using appropriate parametric or non-parametric tests, depending on the distribution of variables. Correlation analyses will be conducted using Pearson or Spearman methods, and the impact of demographic factors on eMAC will be explored using multivariate regression. A p-value <0.05 will be considered statistically significant.
The anticipated enrollment is 60 patients. The study is planned to start in September 2025 and is expected to be completed by November 2025. Findings may provide novel insights into the clinical validity of eMAC as a tool for assessing anesthetic depth, and its relationship with established parameters such as MAC and BIS.
- Being tested
- Sevoflurane + Remifentanil, Sevoflurane + Propofol + Remifentanil
- Keywords
- Equivalent Minimum Alveolar Concentration, eMAC, Minimum Alveolar Concentration, MAC, Bispectral Index, BIS, Anesthesia Depth, Combined Intravenous and Inhalational Anesthesia, CIVIA, Propofol, Sevoflurane
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Sevoflurane + RemifentanilDrug
Combination of an inhalational anesthetic (sevoflurane) and an intravenous opioid analgesic (remifentanil), both routinely used in clinical practice for maintenance of general anesthesia. These agents are administered according to standard of care, not as experimental interventions.
Sevoflurane + Propofol + RemifentanilDrug
Combination of an inhalational anesthetic (sevoflurane), an intravenous anesthetic (propofol), and an intravenous opioid analgesic (remifentanil). These agents are routinely used together in clinical practice for combined intravenous-inhalational anesthesia (CIVIA). All drugs are administered according to standard of care, not as experimental interventions.
| Study group | Role | What they receive |
|---|---|---|
| Inhalational Anesthesia Group | Patients receiving general anesthesia maintained with inhalational agents (e.g., sevoflurane) according to standard clinical practice. Receives: Drug: Sevoflurane + Remifentanil | |
| Combined Intravenous-Inhalational Anesthesia (CIVIA) Group | Patients receiving general anesthesia with a combination of intravenous and inhalational agents according to standard clinical practice. Receives: Drug: Sevoflurane + Propofol + Remifentanil |
What is being measured
The primary outcome is the main question the study is designed to answer.
Correlation between Equivalent Minimum Alveolar Concentration (eMAC) and Minimum Alveolar Concentration (MAC)
To determine the relationship between eMAC values and conventional MAC values obtained from the anesthesia workstation.
Measured: From induction of anesthesia until the end of surgery (measured at five perioperative time points: prior to induction, 5 minutes after induction, at surgical incision, at the midpoint of surgery, and at the end of surgery)
Secondary outcomes (5)
Correlation between eMAC and Bispectral Index (BIS)
To assess the relationship between eMAC values and BIS as indicators of anesthetic depth.
Measured: From induction of anesthesia until the end of surgery (measured at five perioperative time points: prior to induction, 5 minutes after induction, at surgical incision, at the midpoint of surgery, and at the end of surgery)
Comparison of eMAC, MAC, and Bispectral Index (BIS) Values Measured by Anesthesia Workstation and BIS Monitor Across Different Anesthetic Techniques
To compare anesthetic depth parameters obtained from the anesthesia workstation (eMAC and MAC values) and BIS monitor (BIS values) among patients managed with inhalational anesthesia, total intravenous anesthesia (TIVA), or combined intravenous-inhalational anesthesia (CIVIA).
Measured: From induction of anesthesia until the end of surgery (measured at five perioperative time points: prior to induction, 5 minutes after induction, at surgical incision, at the midpoint of surgery, and at the end of surgery)
Heart Rate During Anesthesia
To evaluate heart rate (beats per minute) in relation to anesthetic depth parameters across study groups.
Measured: From induction of anesthesia until the end of surgery (measured at five perioperative time points: prior to induction, 5 minutes after induction, at surgical incision, at the midpoint of surgery, and at the end of surgery)
Mean Arterial Pressure During Anesthesia
To evaluate mean arterial pressure (mmHg) in relation to anesthetic depth parameters across study groups.
Measured: From induction of anesthesia until the end of surgery (measured at five perioperative time points: prior to induction, 5 minutes after induction, at surgical incision, at the midpoint of surgery, and at the end of surgery)
Peripheral Oxygen Saturation (SpO₂) During Anesthesia
To evaluate peripheral oxygen saturation (percentage, %) in relation to anesthetic depth parameters across study groups.
Measured: From induction of anesthesia until the end of surgery (measured at five perioperative time points: prior to induction, 5 minutes after induction, at surgical incision, at the midpoint of surgery, and at the end of surgery)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Sep 2025
- Study start1 Nov 2025
- Primary completion15 Jan 2026
- Study completion15 Jan 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for General 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
- Cohort
- Time perspective
- Prospective
- Enrolment
- 60 participants (actual)
Sponsor and investigators
- Lead sponsor
- Sakarya University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Ayça Taş Tuna, Sakarya University
- Investigators
- Ayca Tas Tuna, Professor, M.D., Principal investigator, Sakarya University Faculty of Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07197567
- Sponsor's protocol ID
- SEAH-EMAC-2025
- Status last verified
- Mar 2026
- First submitted
- 31 Aug 2025
- Last updated
- 10 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data (IPD) will not be shared because this is a single-center observational study with a limited sample size, and data contain potentially identifiable clinical information. Only aggregated results will be reported in publications.
Publications
Zhang H, Zhang J, Li X, He S, Deng Z, Wang L, Wang Y, Wang X, Wan C, Huang F, Zhu Z, Dong H. Feasibility Study of an Indicator of Equivalent Potency of Multiple Anesthetics Normalized by Minimum Alveolar Concentration Derived From Response Surface Models. Anesth Analg. 2026 Mar 1;142(3):541-550. doi: 10.1213/ANE.0000000000007514. Epub 2025 Apr 17.
PubMed 40244902
Study at a glance
From the registry record, last updated by the sponsor on 10 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of Equivalent Minimum Alveolar Concentration During General Anesthesia: An Observational Study
- ClinicalTrials.gov ID
- NCT07197567
- Acronym / sponsor ID
- SEAH-EMAC-2025
- Keywords
- Equivalent Minimum Alveolar Concentration, eMAC, Minimum Alveolar Concentration, MAC, Bispectral Index, BIS, Anesthesia Depth, Combined Intravenous and Inhalational Anesthesia
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 60 participants (actual)
- Lead sponsor
- Sakarya UniversityUniversity, hospital or other
- Study start
- 1 Nov 2025 (actual)
- Primary completion
- 15 Jan 2026 (actual)
- Study completion
- 15 Jan 2026 (actual)
- First posted
- 29 Sep 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 observational study aims to evaluate the clinical applicability of the Equivalent Minimum Alveolar Concentration (eMAC) parameter during general anesthesia. eMAC is a recently developed index that combines the effects of both inhalational and intravenous anesthetics, providing a unified measure of anesthetic depth. While the traditional Minimum Alveolar Concentration (MAC) is widely used for inhalational agents, it does not reflect intravenous anesthetics or combined techniques such as Combined Intravenous and Inhalational Anesthesia (CIVIA).
In this study, adult patients undergoing elective surgery under general anesthesia will be observed. Standard clinical practice will not be altered. Demographic and clinical parameters, including eMAC, MAC, Bispectral Index (BIS), and hemodynamic variables, will be recorded at defined perioperative time points. No experimental drugs or additional procedures will be administered.
The primary aim is to investigate the correlation between eMAC and MAC values obtained during anesthesia. Secondary objectives include assessing the relationship between eMAC and BIS values, comparing eMAC, MAC, and BIS across different anesthetic techniques, and evaluating hemodynamic stability in relation to anesthetic depth.
The results of this study may contribute to a better understanding of eMAC and its potential role in clinical anesthesia practice.
Detailed description
This is a prospective, observational study designed to evaluate the Equivalent Minimum Alveolar Concentration (eMAC) parameter during general anesthesia. eMAC is a composite index that incorporates the anesthetic effects of both inhalational agents and intravenous anesthetics, such as propofol and remifentanil, allowing assessment of anesthetic depth under combined techniques (CIVIA). While the traditional Minimum Alveolar Concentration (MAC) is well established for inhalational agents, its applicability is limited in cases where intravenous agents are administered. eMAC has been proposed as a more comprehensive measure, but clinical validation is lacking.
Adult patients (ages 18-65, ASA I-III) scheduled for elective surgical procedures under general anesthesia will be enrolled. No experimental interventions will be performed; anesthetic management will follow routine clinical practice. Participants will be observed in two groups, based on the anesthetic technique selected by the attending anesthesiologist.
Data collection will include demographic and baseline clinical variables, as well as anesthetic depth parameters (eMAC, MAC, Bispectral Index [BIS]) and hemodynamic variables (heart rate, mean arterial pressure, SpO₂). Measurements will be recorded at predefined time points: prior to induction (T0), 5 minutes after induction (T1), at the beginning of surgery (T2), at the midpoint of surgery (T3), and at the end of surgery (T4).
The primary outcome measure is the correlation between eMAC and MAC values obtained during anesthesia. Secondary outcome measures include the correlation between eMAC and BIS values, comparisons of eMAC, MAC, and BIS among different anesthetic techniques, and evaluation of hemodynamic stability in relation to anesthetic depth.
Statistical analysis will be performed using appropriate parametric or non-parametric tests, depending on the distribution of variables. Correlation analyses will be conducted using Pearson or Spearman methods, and the impact of demographic factors on eMAC will be explored using multivariate regression. A p-value <0.05 will be considered statistically significant.
The anticipated enrollment is 60 patients. The study is planned to start in September 2025 and is expected to be completed by November 2025. Findings may provide novel insights into the clinical validity of eMAC as a tool for assessing anesthetic depth, and its relationship with established parameters such as MAC and BIS.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Inhalational Anesthesia Group | – | Drug: Sevoflurane + RemifentanilPatients receiving general anesthesia maintained with inhalational agents (e.g., sevoflurane) according to standard clinical practice. |
| Combined Intravenous-Inhalational Anesthesia (CIVIA) Group | – | Drug: Sevoflurane + Propofol + RemifentanilPatients receiving general anesthesia with a combination of intravenous and inhalational agents according to standard clinical practice. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Adult patients scheduled for elective surgical procedures under general anesthesia at Sakarya University Training and Research Hospital, Department of Anesthesiology and Reanimation, will be considered for enrollment. Patients represent a typical surgical population with ASA physical status I-III.
Key inclusion criteria (5 listed)
- Adults aged 18-65 years
- Scheduled for elective surgery under general anesthesia
- American Society of Anesthesiologists (ASA) Physical Status I-III
- Feasibility of Bispectral Index (BIS) monitoring
- Provision of written informed consent
Key exclusion criteria (3 listed)
- History of neurological disease (e.g., epilepsy, dementia, severe brain injury)
- Known allergy to anesthetic agents
- Severe cardiovascular or respiratory failure
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 |
|---|---|---|
| Sevoflurane + RemifentanilCombination of an inhalational anesthetic (sevoflurane) and an intravenous opioid analgesic (remifentanil), both routinely used in clinical practice for maintenance of general anesthesia. These agents are administered according to standard of care, not as experimental interventions. | Drug | Inhalational Anesthesia Group |
| Sevoflurane + Propofol + RemifentanilCombination of an inhalational anesthetic (sevoflurane), an intravenous anesthetic (propofol), and an intravenous opioid analgesic (remifentanil). These agents are routinely used together in clinical practice for combined intravenous-inhalational anesthesia (CIVIA). All drugs are administered according to standard of care, not as experimental interventions. | Drug | Combined Intravenous-Inhalational Anesthesia (CIVIA) Group |
Primary outcome
Correlation between Equivalent Minimum Alveolar Concentration (eMAC) and Minimum Alveolar Concentration (MAC)
Time frame: From induction of anesthesia until the end of surgery (measured at five perioperative time points: prior to induction, 5 minutes after induction, at surgical incision, at the midpoint of surgery, and at the end of surgery)
To determine the relationship between eMAC values and conventional MAC values obtained from the anesthesia workstation.
5 secondary outcomes
Correlation between eMAC and Bispectral Index (BIS)
Time frame: From induction of anesthesia until the end of surgery (measured at five perioperative time points: prior to induction, 5 minutes after induction, at surgical incision, at the midpoint of surgery, and at the end of surgery)
Comparison of eMAC, MAC, and Bispectral Index (BIS) Values Measured by Anesthesia Workstation and BIS Monitor Across Different Anesthetic Techniques
Time frame: From induction of anesthesia until the end of surgery (measured at five perioperative time points: prior to induction, 5 minutes after induction, at surgical incision, at the midpoint of surgery, and at the end of surgery)
Heart Rate During Anesthesia
Time frame: From induction of anesthesia until the end of surgery (measured at five perioperative time points: prior to induction, 5 minutes after induction, at surgical incision, at the midpoint of surgery, and at the end of surgery)
Mean Arterial Pressure During Anesthesia
Time frame: From induction of anesthesia until the end of surgery (measured at five perioperative time points: prior to induction, 5 minutes after induction, at surgical incision, at the midpoint of surgery, and at the end of surgery)
Peripheral Oxygen Saturation (SpO₂) During Anesthesia
Time frame: From induction of anesthesia until the end of surgery (measured at five perioperative time points: prior to induction, 5 minutes after induction, at surgical incision, at the midpoint of surgery, and at the end of surgery)
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 10 Mar 2026.
- Background: PubMed 40244902Zhang H, Zhang J, Li X, He S, Deng Z, Wang L, Wang Y, Wang X, Wan C, Huang F, Zhu Z, Dong H. Feasibility Study of an Indicator of Equivalent Potency of Multiple Anesthetics Normalized by Minimum Alveolar Concentration Derived From Response Surface Models. Anesth Analg. 2026 Mar 1;142(3):541-550. doi: 10.1213/ANE.0000000000007514. Epub 2025 Apr 17.
- Individual participant dataSharing planned: No. Individual participant data (IPD) will not be shared because this is a single-center observational study with a limited sample size, and data contain potentially identifiable clinical information. Only aggregated results will be reported in publications.
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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.
Ayca Tas Tuna, Professor, M.D. principal investigator
Sakarya 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 General Anesthesia and Intraoperative Monitoring, run by Sakarya 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 5 inclusion and 3 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 10 Mar 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?
Correlation between Equivalent Minimum Alveolar Concentration (eMAC) and Minimum Alveolar Concentration (MAC) (time frame: From induction of anesthesia until the end of surgery (measured at five perioperative time points: prior to induction, 5 minutes after induction, at surgical incision, at the midpoint of surgery, and at the end of 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 NCT07197567, which also lists 1 linked publication.
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 10 Mar 2026.