Postoperative Cognitive DysfunctionNCT07424729
Minimal-flow Anesthesia and Cognitive Outcomes in Elderly Surgical Patients
A study testing Mini-Mental State Examination in people with Postoperative Cognitive Dysfunction, run by Ankara Etlik City Hospital at 1 site in Turkey (Türkiye).
Trial summary
Purpose: Postoperative cognitive dysfunction (POCD) is a common complication in elderly patients following major surgery and is associated with impaired attention, memory, and executive functions. Advanced age and prolonged surgical duration are among the most important risk factors. Read more about this study
- Who is it for?
- Ages 65 to 85 years
- Conditions the study is for
- Postoperative Cognitive Dysfunction
- What is being tested?
- Mini-Mental State Examination
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 90 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 3 Oct 2025to 15 Mar 2026
- Phase
- Interventional
- 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 65 to 85 years
- All sexes
- No healthy volunteers
- Older adult
Who may be able to join
- Patients aged between 65 and 85 years
- ASA physical status I-III
- Scheduled for elective surgery under general anesthesia in general surgery or otorhinolaryngology operating rooms
- Planned to receive minimal flow general anesthesia
- Preoperative Mini-Mental State Examination performed
- Able to provide informed consent
Who cannot join
- Age outside the specified range
- ASA physical status IV or higher
- Severe comorbid disease affecting perioperative stability
- Surgery performed under regional anesthesia
- History of alcohol, drug, or substance abuse
- Significant visual or hearing impairment interfering with cognitive testing
Show all 13Show fewer
- Refusal to participate
- Known neurological or psychiatric disorders
- Preoperative MMSE score below 24
- Perioperative hemodynamic instability
- Illiteracy preventing completion of cognitive tests
- Postoperative admission to intensive care unit
- -
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Ankara Etlik City Hospital
Yenimahalle, Ankara, 06170
About this study
Official title: Minimal-flow Anesthesia, Surgical Duration, and Postoperative Cognitive Dysfunction in Older Patients
Purpose:
Postoperative cognitive dysfunction (POCD) is a common complication in elderly patients following major surgery and is associated with impaired attention, memory, and executive functions. Advanced age and prolonged surgical duration are among the most important risk factors. Minimal flow anesthesia has been suggested to reduce postoperative cognitive impairment by providing more stable anesthetic depth and reducing physiological stress.
The aim of this study is to investigate the relationship between surgical duration and postoperative cognitive dysfunction in elderly patients undergoing surgery under minimal flow anesthesia.
Read the detailed description
Detailed Description:
Postoperative cognitive dysfunction (POCD) is a syndrome characterized by deterioration in cognitive domains such as attention, memory, executive function, and psychomotor speed, particularly in elderly patients after major surgical procedures. POCD may become evident in the early postoperative hours or may present days to weeks after surgery. Its incidence increases with age, prolonged surgical duration, anesthetic technique, comorbid conditions, and perioperative physiological disturbances.
Diagnosis of POCD requires comparison of preoperative baseline cognitive status with postoperative neurocognitive assessments. The Mini-Mental State Examination (MMSE) and the Richmond Agitation-Sedation Scale (RASS) are validated and reliable tools for evaluating cognitive status in the perioperative period.
Minimal flow anesthesia is defined as the use of fresh gas flow rates between 0.25 and 0.5 L/min, allowing partial rebreathing of anesthetic agents. This technique reduces anesthetic consumption, maintains stable anesthetic depth, and preserves temperature and humidity, potentially minimizing physiological stress. Previous studies suggest that minimal flow anesthesia with sevoflurane may be associated with a lower incidence of early postoperative cognitive impairment compared to higher flow techniques.
In this prospective interventional study, patients aged 65-85 years undergoing surgery under minimal flow inhalational anesthesia will be enrolled. Patients will be divided into two groups based on surgical duration: surgeries lasting less than 2 hours and surgeries lasting 2 hours or longer, with 45 patients in each group.
All patients will undergo preoperative cognitive assessment using the MMSE. Standard ASA monitoring and bispectral index (BIS) monitoring will be applied intraoperatively to maintain anesthetic depth between BIS values of 40 and 60. Anesthesia induction and maintenance will be performed using routine anesthetic agents and minimal flow inhalational anesthesia as part of standard clinical practice.
Neuromuscular blockade will be reversed with sugammadex at the end of surgery. Postoperatively, patients will be evaluated using the RASS at the 10th, 30th, and 60th minutes in the recovery room. Neurology consultation will be requested for patients with RASS scores outside the normal range. Vital signs, pain scores (VAS), and blood glucose levels will be recorded during these assessments.
Postoperative cognitive function will be reassessed using the MMSE at 24 hours and on postoperative day 7. Preoperative and postoperative cognitive assessments will be conducted by study investigators who are blinded to surgical duration. The anesthetic management will be performed by anesthesiologists not involved in the study.
The primary objective of this study is to evaluate the association between surgical duration and postoperative cognitive dysfunction in elderly patients undergoing surgery under minimal flow anesthesia.
- Conditions
- Postoperative Cognitive Dysfunction
- Being tested
- Mini-Mental State Examination
- Keywords
- Postoperative cognitive dysfunction, Minimal flow anesthesia, Elderly patients, Mini-Mental State Examination, Surgical duration
- Medical subject headings
- Postoperative Cognitive Complications
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Mini-Mental State ExaminationOther
Also called MMSE
Cognitive function will be assessed using the Mini-Mental State Examination preoperatively and at postoperative time points.
| Study group | Role | What they receive |
|---|---|---|
| Arm 1: Surgery duration <2 hours | Experimental | Elderly patients undergoing surgery under minimal flow anesthesia with a surgical duration of less than 2 hours. Cognitive function will be assessed preoperatively and postoperatively using the Mini-Mental State Examination. Receives: Other: Mini-Mental State Examination |
| Arm 2: Surgery duration ≥2 hours | Experimental | Elderly patients undergoing surgery under minimal flow anesthesia with a surgical duration of 2 hours or longer. Cognitive function will be assessed preoperatively and postoperatively using the Mini-Mental State Examination. Receives: Other: Mini-Mental State Examination |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Mini-Mental State Examination score
Cognitive function will be assessed using the Mini-Mental State Examination (MMSE), a 30-point scale ranging from 0 to 30, where higher scores indicate better cognitive function. The primary outcome is the change in MMSE score between the preoperative assessment and postoperative assessments.
Change in cognitive function assessed by the difference between preoperative and postoperative Mini-Mental State Examination scores.
Measured: Preoperative baseline, postoperative 24 hours, and postoperative day 7
Secondary outcomes (1)
Incidence of postoperative cognitive dysfunction
The proportion of patients who develop postoperative cognitive dysfunction based on changes in Mini-Mental State Examination (MMSE) scores. Postoperative cognitive dysfunction will be defined according to a predefined decline in MMSE score compared with the preoperative baseline assessment.
Measured: Postoperative 24 hours and postoperative day 7
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Feb 2026
- Study start3 Oct 2025
- Primary completion12 Mar 2026
- Study completion15 Mar 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 Postoperative Cognitive DysfunctionStudies of the same condition, open and under way.
- More trials run by Ankara Etlik City HospitalThe 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Model description
- Participants will be assigned into two parallel groups according to surgical duration (less than 2 hours or longer) and postoperative cognitive outcomes will be compared between groups.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 90 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ankara Etlik City Hospital
- Sponsor type
- Other government
- Responsible party
- Principal investigator, oya Çimen, Ankara Etlik City Hospital
- Investigators
- oya çimen, MD, Principal investigator, Ankara Etlik City Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07424729
- Sponsor's protocol ID
- AEŞH-EK-2025-187
- Status last verified
- Mar 2026
- First submitted
- 5 Feb 2026
- Last updated
- 18 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be shared because the study involves a single-center academic dataset and no data-sharing agreement has been established. De-identified data may be made available upon reasonable request to the principal investigator.
Publications
Evered L, Silbert B, Knopman DS, Scott DA, DeKosky ST, Rasmussen LS, Oh ES, Crosby G, Berger M, Eckenhoff RG; Nomenclature Consensus Working Group. Recommendations for the Nomenclature of Cognitive Change Associated with Anaesthesia and Surgery-2018. Anesthesiology. 2018 Nov;129(5):872-879. doi: 10.1097/ALN.0000000000002334.
PubMed 30325806
Study at a glance
From the registry record, last updated by the sponsor on 18 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Minimal-flow Anesthesia, Surgical Duration, and Postoperative Cognitive Dysfunction in Older Patients
- ClinicalTrials.gov ID
- NCT07424729
- Acronym / sponsor ID
- AEŞH-EK-2025-187
- Conditions
- Postoperative Cognitive Dysfunction
- Keywords
- Postoperative cognitive dysfunction, Minimal flow anesthesia, Elderly patients, Mini-Mental State Examination, Surgical duration
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 90 participants (actual)
- Lead sponsor
- Ankara Etlik City HospitalOther government
- Study start
- 3 Oct 2025 (actual)
- Primary completion
- 12 Mar 2026 (actual)
- Study completion
- 15 Mar 2026 (actual)
- First posted
- 20 Feb 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.
Purpose:
Postoperative cognitive dysfunction (POCD) is a common complication in elderly patients following major surgery and is associated with impaired attention, memory, and executive functions. Advanced age and prolonged surgical duration are among the most important risk factors. Minimal flow anesthesia has been suggested to reduce postoperative cognitive impairment by providing more stable anesthetic depth and reducing physiological stress.
The aim of this study is to investigate the relationship between surgical duration and postoperative cognitive dysfunction in elderly patients undergoing surgery under minimal flow anesthesia.
Detailed description
Detailed Description:
Postoperative cognitive dysfunction (POCD) is a syndrome characterized by deterioration in cognitive domains such as attention, memory, executive function, and psychomotor speed, particularly in elderly patients after major surgical procedures. POCD may become evident in the early postoperative hours or may present days to weeks after surgery. Its incidence increases with age, prolonged surgical duration, anesthetic technique, comorbid conditions, and perioperative physiological disturbances.
Diagnosis of POCD requires comparison of preoperative baseline cognitive status with postoperative neurocognitive assessments. The Mini-Mental State Examination (MMSE) and the Richmond Agitation-Sedation Scale (RASS) are validated and reliable tools for evaluating cognitive status in the perioperative period.
Minimal flow anesthesia is defined as the use of fresh gas flow rates between 0.25 and 0.5 L/min, allowing partial rebreathing of anesthetic agents. This technique reduces anesthetic consumption, maintains stable anesthetic depth, and preserves temperature and humidity, potentially minimizing physiological stress. Previous studies suggest that minimal flow anesthesia with sevoflurane may be associated with a lower incidence of early postoperative cognitive impairment compared to higher flow techniques.
In this prospective interventional study, patients aged 65-85 years undergoing surgery under minimal flow inhalational anesthesia will be enrolled. Patients will be divided into two groups based on surgical duration: surgeries lasting less than 2 hours and surgeries lasting 2 hours or longer, with 45 patients in each group.
All patients will undergo preoperative cognitive assessment using the MMSE. Standard ASA monitoring and bispectral index (BIS) monitoring will be applied intraoperatively to maintain anesthetic depth between BIS values of 40 and 60. Anesthesia induction and maintenance will be performed using routine anesthetic agents and minimal flow inhalational anesthesia as part of standard clinical practice.
Neuromuscular blockade will be reversed with sugammadex at the end of surgery. Postoperatively, patients will be evaluated using the RASS at the 10th, 30th, and 60th minutes in the recovery room. Neurology consultation will be requested for patients with RASS scores outside the normal range. Vital signs, pain scores (VAS), and blood glucose levels will be recorded during these assessments.
Postoperative cognitive function will be reassessed using the MMSE at 24 hours and on postoperative day 7. Preoperative and postoperative cognitive assessments will be conducted by study investigators who are blinded to surgical duration. The anesthetic management will be performed by anesthesiologists not involved in the study.
The primary objective of this study is to evaluate the association between surgical duration and postoperative cognitive dysfunction in elderly patients undergoing surgery under minimal flow anesthesia.
Study design
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- Participants will be assigned into two parallel groups according to surgical duration (less than 2 hours or longer) and postoperative cognitive outcomes will be compared between groups.
| Arm | Type | Receives |
|---|---|---|
| Arm 1: Surgery duration <2 hours | Experimental | Other: Mini-Mental State ExaminationElderly patients undergoing surgery under minimal flow anesthesia with a surgical duration of less than 2 hours. Cognitive function will be assessed preoperatively and postoperatively using the Mini-Mental State Examination. |
| Arm 2: Surgery duration ≥2 hours | Experimental | Other: Mini-Mental State ExaminationElderly patients undergoing surgery under minimal flow anesthesia with a surgical duration of 2 hours or longer. Cognitive function will be assessed preoperatively and postoperatively using the Mini-Mental State Examination. |
Who may qualify
- Ages
- 65 to 85 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Older adult
Key inclusion criteria (6 listed)
- Patients aged between 65 and 85 years
- ASA physical status I-III
- Scheduled for elective surgery under general anesthesia in general surgery or otorhinolaryngology operating rooms
- Planned to receive minimal flow general anesthesia
- Preoperative Mini-Mental State Examination performed
Key exclusion criteria (13 listed)
- Age outside the specified range
- ASA physical status IV or higher
- Severe comorbid disease affecting perioperative stability
- Surgery performed under regional anesthesia
- History of alcohol, drug, or substance abuse
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 |
|---|---|---|
| Mini-Mental State ExaminationAlso: MMSECognitive function will be assessed using the Mini-Mental State Examination preoperatively and at postoperative time points. | Other | Arm 1: Surgery duration <2 hours, Arm 2: Surgery duration ≥2 hours |
Primary outcome
Change in Mini-Mental State Examination score
Time frame: Preoperative baseline, postoperative 24 hours, and postoperative day 7
Cognitive function will be assessed using the Mini-Mental State Examination (MMSE), a 30-point scale ranging from 0 to 30, where higher scores indicate better cognitive function. The primary outcome is the change in MMSE score between the preoperative assessment and postoperative assessments. Change in cognitive function assessed by the difference between preoperative and postoperative Mini-Mental State Examination scores.
1 secondary outcome
Incidence of postoperative cognitive dysfunction
Time frame: Postoperative 24 hours and postoperative day 7
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 18 Mar 2026.
- Background: PubMed 30325806Evered L, Silbert B, Knopman DS, Scott DA, DeKosky ST, Rasmussen LS, Oh ES, Crosby G, Berger M, Eckenhoff RG; Nomenclature Consensus Working Group. Recommendations for the Nomenclature of Cognitive Change Associated with Anaesthesia and Surgery-2018. Anesthesiology. 2018 Nov;129(5):872-879. doi: 10.1097/ALN.0000000000002334.
- This reference provides background on postoperative cognitive dysfunction and terminology related to cognitive changes associated with anesthesia and surgery.Link provided by the sponsor.
- Individual participant dataSharing planned: No. Individual participant data will not be shared because the study involves a single-center academic dataset and no data-sharing agreement has been established. De-identified data may be made available upon reasonable request to the principal investigator.
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The Effect of Single Lung Ventilation Duration and Intraoperative Brain Oxygenation on Cognitive Function and Postoperative Pain in Geriatric Patients
Thoracic Anesthesia, Geriatric Anesthesia
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Effects of Remimazolam on Postoperative Cognitive Dysfunction and Neuroinflammatory Biomarkers in Patients Undergoing Aortic Arch Surgery
Aortic Aneurysm of the Proximal Arch, Aortic Aneurysms Arch
Enrolling by invitationPhase 4
Effects of Ciprofol on Perioperative Neurocognitive Function in Elderly Patients Undergoing Daytime Surgery
PND, POCD - Postoperative Cognitive Dysfunction
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.
oya çimen, MD principal investigator
Ankara Etlik City Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Mini-Mental State Examination in people with Postoperative Cognitive Dysfunction, run by Ankara Etlik City Hospital at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 13 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 18 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?
Change in Mini-Mental State Examination score (time frame: Preoperative baseline, postoperative 24 hours, and postoperative day 7). 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 NCT07424729, 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 18 Mar 2026.