Minimal-flow Anesthesia and Cognitive Outcomes in Elderly Surgical Patients

NCT07424729 | Completed

• 1 other identifier: AEŞH-EK-2025-187
• Study Type: interventional
• Target: 90
• Locations: 1 country
• Sites: 1

Brief 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. 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.

Conditions

Postoperative Cognitive Dysfunction

Keywords

Postoperative cognitive dysfunction; Minimal flow anesthesia; Elderly patients; Mini-Mental State Examination; Surgical duration

Outcome Measures

Primary Outcomes (1)

• 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.

  Preoperative baseline, postoperative 24 hours, and postoperative day 7

Secondary Outcomes (1)

• Incidence of postoperative cognitive dysfunction

  Postoperative 24 hours and postoperative day 7

Study Arms (2)

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.

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.

Other: Mini-Mental State Examination

Interventions

Mini-Mental State Examination OTHER

Cognitive function will be assessed using the Mini-Mental State Examination preoperatively and at postoperative time points.

Also known as: MMSE

Arm 1: Surgery duration <2 hours; Arm 2: Surgery duration ≥2 hours

Eligibility Criteria

• Age: 65 Years - 85 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• 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
• 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

Sponsors & Collaborators

• Ankara Etlik City Hospital: lead

Study Sites (1)

Ankara Etlik City Hospital

Yenimahalle, Ankara, 06170, Turkey (Türkiye)

Location

Related Publications (1)

• 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.

  PMID: 30325806 BACKGROUND

Related Links

• This reference provides background on postoperative cognitive dysfunction and terminology related to cognitive changes associated with anesthesia and surgery.

MeSH Terms

Conditions

Postoperative Cognitive Complications

Interventions

Mental Status and Dementia Tests

Condition Hierarchy (Ancestors)

Postoperative Complications; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Cognitive Dysfunction; Cognition Disorders; Neurocognitive Disorders; Mental Disorders

Intervention Hierarchy (Ancestors)

Neuropsychological Tests; Psychological Tests; Behavioral Disciplines and Activities

Study Officials

• oya çimen, MD

  Ankara Etlik City Hospital

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: Outcome assessors performing the cognitive evaluations will be blinded to surgical duration and intraoperative management.
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Specialist Physician

Model Details: 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.

Study Record Dates

• First Submitted: February 5, 2026
• First Posted: February 20, 2026
• Study Start: October 3, 2025
• Primary Completion: March 12, 2026
• Study Completion: March 15, 2026
• Last Updated: March 18, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)