Bispectral Index Variability During General Anesthesia and Postoperative RecoveryNCT07454629
BIS Variability and Change in Quality of Recovery After Surgery
An observational study of Bispectral Index Variability During General Anesthesia and Postoperative Recovery and Cholecystectomy, Laparoscopic, run by Sakarya University at 1 site in Turkey (Türkiye).
Trial summary
This prospective observational study aims to examine the relationship between fluctuations in anesthesia depth, measured by bispectral index (BIS) monitoring during surgery, and changes in patients' postoperative recovery quality. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Bispectral Index Variability During General Anesthesia and Postoperative Recovery, Cholecystectomy, Laparoscopic
- How many people
- 126 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Jan 2026to 1 Jun 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: The study population consists of adult patients aged 18 to 65 years undergoing elective laparoscopic cholecystectomy under general anesthesia. All participants will receive routine perioperative care according to standard clinical practice, including intraoperative bispectral index (BIS) monitoring. The study includes a single prospective observational cohort, and no experimental intervention or alteration of standard anesthesia management will be performed. Participants will be assessed preoperatively and postoperatively to evaluate changes in recovery quality following surgery.
Who may be able to join
- Adults aged 18 to 65 years
- Scheduled for elective laparoscopic cholecystectomy
- American Society of Anesthesiologists (ASA) physical status I-III
- Planned general anesthesia with routine bispectral index (BIS) monitoring
- Ability to provide written informed consent
Who cannot join
- History of neurological disease
- Use of neuropsychiatric medications
- Cognitive impairment or mental retardation
- Inability to complete the Quality of Recovery-15 (QoR-15) questionnaire
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, Serdivan, 54000
About this study
Official title: Association Between Intraoperative Bispectral Index Variability and Change in Quality of Recovery-15 Score: A Prospective Observational Study
This prospective observational study aims to examine the relationship between fluctuations in anesthesia depth, measured by bispectral index (BIS) monitoring during surgery, and changes in patients' postoperative recovery quality.
BIS monitoring is routinely used during general anesthesia to assess the depth of anesthesia, but BIS values often fluctuate over time rather than remaining stable. The clinical significance of this variability is not well understood. In this study, BIS variability during anesthesia induction and maintenance will be evaluated and compared with changes in postoperative recovery quality.
Read more
Recovery quality will be assessed using the Quality of Recovery-15 (QoR-15) questionnaire, which will be administered before surgery and again on the first postoperative day. The primary outcome of the study will be the change in QoR-15 score from the preoperative baseline to postoperative day one (ΔQoR-15). Delirium screening and routine perioperative clinical data will also be collected.
No additional interventions beyond standard anesthesia care will be performed. The results of this study may help improve understanding of how intraoperative anesthesia stability relates to patient recovery after surgery.
Read the detailed description
Bispectral index (BIS) monitoring is widely used in routine anesthesia practice to assess anesthetic depth using processed electroencephalographic signals. Although absolute BIS values are commonly targeted during anesthesia, BIS readings frequently exhibit intraoperative fluctuations rather than remaining stable. The clinical relevance of this variability, particularly in relation to postoperative recovery outcomes, remains insufficiently characterized.
This prospective observational study is designed to evaluate the association between intraoperative BIS variability and changes in postoperative recovery quality. Adult patients undergoing elective laparoscopic cholecystectomy under standardized general anesthesia will be included. No experimental intervention or protocol-driven modification of anesthetic management will be applied beyond routine clinical care.
BIS data will be obtained as part of standard anesthesia monitoring and exported from the BIS monitor at the end of each procedure. Only BIS measurements meeting predefined signal quality criteria will be included in the analysis. BIS variability will be quantified using statistical dispersion measures derived from filtered BIS data during predefined anesthesia phases, including induction and maintenance.
Postoperative recovery quality will be assessed using the Quality of Recovery-15 (QoR-15) questionnaire. QoR-15 will be administered preoperatively to establish baseline status and repeated on postoperative day one. The primary outcome will be defined as the change in QoR-15 score from baseline to postoperative day one (ΔQoR-15). Screening for postoperative delirium and routine perioperative clinical variables will be collected as secondary or exploratory outcomes.
Statistical analyses will focus on assessing the association between BIS variability metrics and ΔQoR-15, with additional analyses performed to account for relevant perioperative variables. The findings of this study are expected to contribute to a better understanding of how intraoperative anesthetic stability relates to patient-centered recovery outcomes following surgery.
- Conditions
- Bispectral Index Variability During General Anesthesia and Postoperative Recovery, Cholecystectomy, Laparoscopic
- Keywords
- Bispectral Index, Anesthesia Depth, Quality of Recovery, General Anesthesia, Postoperative Recovery, Bispectral Index Variability
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 |
|---|---|---|
| Elective Laporoscopic Cholecystectomy Patients Undergoing General Anesthesia | This cohort consists of adult patients undergoing elective laparoscopic cholecystectomy under general anesthesia. All participants will receive routine anesthetic management according to standard clinical practice. No experimental intervention or protocol-driven modification of anesthesia care will be applied. Intraoperative bispectral index (BIS) monitoring will be used as part of standard anesthesia monitoring. BIS data and routine perioperative clinical variables will be recorded for observational analysis. Postoperative recovery will be assessed using validated questionnaires administered before surgery and on postoperative day one. The study involves a single observational cohort without a comparison or control group. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Quality of Recovery-15 (ΔQoR-15) Score
The primary outcome is the change in postoperative recovery quality measured using the Quality of Recovery-15 (QoR-15) questionnaire. ΔQoR-15 is defined as the difference between the postoperative day one QoR-15 total score and the preoperative baseline QoR-15 total score. The QoR-15 is a validated 15-item questionnaire with total scores ranging from 0 to 150 points, where higher scores indicate better recovery quality. ΔQoR-15 will be analyzed as a continuous variable (points).
Measured: From preoperative baseline to postoperative day one
Secondary outcomes (2)
Incidence of Postoperative Delirium (Nu-DESC ≥ 2)
Postoperative delirium will be assessed using the Nursing Delirium Screening Scale (Nu-DESC). Delirium will be defined as a Nu-DESC total score ≥ 2 during early postoperative recovery in the PACU. The outcome will be reported as the percentage of patients meeting delirium criteria (%).
Measured: From preoperative baseline to early postoperative recovery in the post-anesthesia care unit (PACU), within the first 2 hours after anesthesia
Postoperative Pain Intensity (VAS)
Postoperative pain intensity will be assessed using a visual analog scale (VAS) as part of routine clinical evaluation during the early postoperative period. The relationship between intraoperative BIS variability and postoperative pain scores will be explored as a secondary outcome.
Measured: Postoperative day 1
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Mar 2026
- Study start1 Jan 2026
- Primary completion1 Apr 2026
- Study completion1 Jun 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Bispectral Index Variability During General Anesthesia and Postoperative RecoveryStudies of the same condition, open and under way.
- More trials run by Sakarya UniversityThe sponsor's other registered studies.
- 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
- 126 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
- Ayça Taş Tuna, Professor, M.D., Principal investigator, Sakarya University Faculty of Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07454629
- Sponsor's protocol ID
- SEAH-BISVARIABILITY-2026
- Status last verified
- Aug 2026
- First submitted
- 18 Feb 2026
- Last updated
- 2 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: Individual participant data (IPD) sharing plans have not yet been determined. Decisions regarding data sharing will depend on institutional policies, ethical considerations, and data anonymization requirements, and may be addressed following completion of the study and primary analyses.
Study at a glance
From the registry record, last updated by the sponsor on 2 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Association Between Intraoperative Bispectral Index Variability and Change in Quality of Recovery-15 Score: A Prospective Observational Study
- ClinicalTrials.gov ID
- NCT07454629
- Acronym / sponsor ID
- SEAH-BISVARIABILITY-2026
- Conditions
- Bispectral Index Variability During General Anesthesia and Postoperative Recovery, Cholecystectomy, Laparoscopic
- Keywords
- Bispectral Index, Anesthesia Depth, Quality of Recovery, General Anesthesia, Postoperative Recovery, Bispectral Index Variability
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 126 participants (actual)
- Lead sponsor
- Sakarya UniversityUniversity, hospital or other
- Study start
- 1 Jan 2026 (actual)
- Primary completion
- 1 Apr 2026 (actual)
- Study completion
- 1 Jun 2026 (actual)
- First posted
- 6 Mar 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.
This prospective observational study aims to examine the relationship between fluctuations in anesthesia depth, measured by bispectral index (BIS) monitoring during surgery, and changes in patients' postoperative recovery quality.
BIS monitoring is routinely used during general anesthesia to assess the depth of anesthesia, but BIS values often fluctuate over time rather than remaining stable. The clinical significance of this variability is not well understood. In this study, BIS variability during anesthesia induction and maintenance will be evaluated and compared with changes in postoperative recovery quality.
Recovery quality will be assessed using the Quality of Recovery-15 (QoR-15) questionnaire, which will be administered before surgery and again on the first postoperative day. The primary outcome of the study will be the change in QoR-15 score from the preoperative baseline to postoperative day one (ΔQoR-15). Delirium screening and routine perioperative clinical data will also be collected.
No additional interventions beyond standard anesthesia care will be performed. The results of this study may help improve understanding of how intraoperative anesthesia stability relates to patient recovery after surgery.
Detailed description
Bispectral index (BIS) monitoring is widely used in routine anesthesia practice to assess anesthetic depth using processed electroencephalographic signals. Although absolute BIS values are commonly targeted during anesthesia, BIS readings frequently exhibit intraoperative fluctuations rather than remaining stable. The clinical relevance of this variability, particularly in relation to postoperative recovery outcomes, remains insufficiently characterized.
This prospective observational study is designed to evaluate the association between intraoperative BIS variability and changes in postoperative recovery quality. Adult patients undergoing elective laparoscopic cholecystectomy under standardized general anesthesia will be included. No experimental intervention or protocol-driven modification of anesthetic management will be applied beyond routine clinical care.
BIS data will be obtained as part of standard anesthesia monitoring and exported from the BIS monitor at the end of each procedure. Only BIS measurements meeting predefined signal quality criteria will be included in the analysis. BIS variability will be quantified using statistical dispersion measures derived from filtered BIS data during predefined anesthesia phases, including induction and maintenance.
Postoperative recovery quality will be assessed using the Quality of Recovery-15 (QoR-15) questionnaire. QoR-15 will be administered preoperatively to establish baseline status and repeated on postoperative day one. The primary outcome will be defined as the change in QoR-15 score from baseline to postoperative day one (ΔQoR-15). Screening for postoperative delirium and routine perioperative clinical variables will be collected as secondary or exploratory outcomes.
Statistical analyses will focus on assessing the association between BIS variability metrics and ΔQoR-15, with additional analyses performed to account for relevant perioperative variables. The findings of this study are expected to contribute to a better understanding of how intraoperative anesthetic stability relates to patient-centered recovery outcomes following surgery.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Elective Laporoscopic Cholecystectomy Patients Undergoing General Anesthesia | – | –This cohort consists of adult patients undergoing elective laparoscopic cholecystectomy under general anesthesia. All participants will receive routine anesthetic management according to standard clinical practice. No experimental intervention or protocol-driven modification of anesthesia care will be applied. Intraoperative bispectral index (BIS) monitoring will be used as part of standard anesthesia monitoring. BIS data and routine perioperative clinical variables will be recorded for observational analysis. Postoperative recovery will be assessed using validated questionnaires administered before surgery and on postoperative day one. The study involves a single observational cohort without a comparison or control group. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- The study population consists of adult patients aged 18 to 65 years undergoing elective laparoscopic cholecystectomy under general anesthesia. All participants will receive routine perioperative care according to standard clinical practice, including intraoperative bispectral index (BIS) monitoring. The study includes a single prospective observational cohort, and no experimental intervention or alteration of standard anesthesia management will be performed. Participants will be assessed preoperatively and postoperatively to evaluate changes in recovery quality following surgery.
Key inclusion criteria (5 listed)
- Adults aged 18 to 65 years
- Scheduled for elective laparoscopic cholecystectomy
- American Society of Anesthesiologists (ASA) physical status I-III
- Planned general anesthesia with routine bispectral index (BIS) monitoring
- Ability to provide written informed consent
Key exclusion criteria (4 listed)
- History of neurological disease
- Use of neuropsychiatric medications
- Cognitive impairment or mental retardation
- Inability to complete the Quality of Recovery-15 (QoR-15) questionnaire
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 Quality of Recovery-15 (ΔQoR-15) Score
Time frame: From preoperative baseline to postoperative day one
The primary outcome is the change in postoperative recovery quality measured using the Quality of Recovery-15 (QoR-15) questionnaire. ΔQoR-15 is defined as the difference between the postoperative day one QoR-15 total score and the preoperative baseline QoR-15 total score. The QoR-15 is a validated 15-item questionnaire with total scores ranging from 0 to 150 points, where higher scores indicate better recovery quality. ΔQoR-15 will be analyzed as a continuous variable (points).
2 secondary outcomes
Incidence of Postoperative Delirium (Nu-DESC ≥ 2)
Time frame: From preoperative baseline to early postoperative recovery in the post-anesthesia care unit (PACU), within the first 2 hours after anesthesia
Postoperative Pain Intensity (VAS)
Time frame: Postoperative day 1
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 2 Sep 2026.
- Individual participant dataSharing planned: Undecided. Individual participant data (IPD) sharing plans have not yet been determined. Decisions regarding data sharing will depend on institutional policies, ethical considerations, and data anonymization requirements, and may be addressed following completion of the study and primary analyses.
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.
Ayça Taş 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 Bispectral Index Variability During General Anesthesia and Postoperative Recovery and Cholecystectomy, Laparoscopic, 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 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: finished, as of the sponsor's last update on 2 Sep 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 Quality of Recovery-15 (ΔQoR-15) Score (time frame: From preoperative baseline to postoperative day one). 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 2 Sep 2026.