Cognitive Function in Geriatric Colonoscopy Patients

February 6, 2026 updated by: Ankara City Hospital Bilkent

The Impact of Frailty and Different Sedation Techniques on Cognitive Function in Geriatric Colonoscopy Patients

Procedures such as colonoscopy cause discomfort and pain and are therefore performed under sedation and analgesia. Although patients aged 65 and older frequently undergo colonoscopy procedures, it is unclear to what extent the anesthetic agents administered for sedation and analgesia in this patient group affect neurocognitive functions. Different sedation methods are used in colonoscopy procedures depending on the anesthesiologist's choice. Propofol is an agent frequently used in general anesthesia or for sedation during endoscopic procedures and, compared to inhaled agents, has more positive effects on postoperative cognitive functions. Dexmedetomidine is an alpha receptor agonist and is preferred due to its positive effects on cognitive functions in elderly patients, its lack of respiratory depression, its ability to provide sedation without impairing cooperation, and its analgesic effects. Although there are studies in the literature on the assessment of neurocognitive function in geriatric patients undergoing surgical procedures, the literature is insufficient in terms of studies addressing cognitive assessment after short-term, outpatient, and less invasive procedures such as colonoscopy. This study aimed to observe patients aged 65 years and older who underwent sedoanalgesia for colonoscopy and to compare the effects on cognitive function by administering the mini mental test before and after the procedure to this patient group.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

This study was observational and prospective, and included 164 hospitalized patients aged 65 years and older who received propofol or dexmedetomidine for sedation during colonoscopy. Patients were admitted to the preparation room in the endoscopy unit 30 minutes before the start of colonoscopy. The patients' age, education level (divided into two separate categories: one group with high school education and above, and the other group with less education), Body Mass Index (BMI), American Society of Anesthesiologists (ASA) risk status, and comorbidities were recorded. To assess cognitive function, the Mini Mental State Examination (MMSE) was administered by an investigator who was unaware of which sedation agent would be administered. The patient's degree of frailty was determined using the Frailty Questionnaire. The MMSE was repeated 2 hours after the colonoscopy procedure was completed and at 24 hours. Patients were monitored in the post-anesthesia recovery room using the Modified Aldrete Scoring System. Assessment was performed at 2 hours after the Aldrete Score reached 10 points. Colonoscopy procedures were performed in two separate rooms by two anesthesiologists using two different sedation methods. In our study, patients were observed by anesthesiologists independent of the study in these two rooms. Patients in both groups were started with 3 L/min O2 via a nasal cannula upon entering the room. Patients were monitored for heart rate (HR), systolic arterial blood pressure (SABP), diastolic arterial blood pressure (DABP), mean arterial blood pressure (MAP), and arterial oxygen saturation (SpO2), and baseline measurements of hemodynamic variables were recorded at 5 min, 10 min, and 15 min. Both groups received 0.5 µg/kg fentanyl (IV). In the propofol group (P), the propofol loading dose was 0.2-0.5 mg/kg, and maintenance was continued with repeated boluses. In the dexmedetomidine (D) group, a loading dose of 0.5 μg/kg-1 dexmedetomidine was administered over 10 minutes. When necessary, patients receive propofol 0.1mg/kg push. Ramsey score was maintained at level 3-4 for effective sedation. Colonoscopy procedure duration, total propofol and dexmedetomidine amounts used, and additional atropine and ephedrine administered were recorded. Medications were discontinued upon completion of colonoscopy. Patients were evaluated using the Modified Aldrete Score in the postoperative recovery room and then transferred to the ward. Patients were excluded from the study if complications such as bleeding, perforation, respiratory arrest, or cardiac arrest developed due to the colonoscopy or anesthesia.

Study Type

Observational

Enrollment (Actual)

164

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Turkey (Türkiye)
    • Çankaya
      • Ankara, Çankaya, Turkey (Türkiye), 06800
        • Ankara Bilkent City Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Probability Sample

Study Population

65 years and older

Description

Inclusion Criteria:

  • Age ≥65 years
  • Elective colonoscopy
  • ASA physical status I-III
  • Provision of written informed consent

Exclusion Criteria:

  • Second- or third-degree atrioventricular (AV) block
  • A recent history of strokes
  • Severe hypotension
  • Cardiorespiratory instability
  • Substance abuse
  • Psychotic illness
  • Severe dementia

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Propofol
Aged 65 years and older who received propofol
Drug: Propofol Group
To evaluate cognitive function, Mini Mental State Examination (MMSE) was administered 3 times before the procedure and 2 hours and 24 hours after the procedure. Frailty level of the patient was determined using the frail frailty questionnaire. Each patient received 0.5µg/kg fentanyl (iv).propofol loading dose: 0.2-0.5 mg/kg, continued as repeated boluses for maintenance.
Other Names:
  • P Group
Dexmedetomidine
Aged 65 years and older who received dexmedetomidine
Drug: Dexmedetomidine group
To evaluate cognitive function, Mini Mental State Examination (MMSE) was administered 3 times before the procedure and 2 hours and 24 hours after the procedure. Frailty level of the patient was determined using the frail frailty questionnaire. Each patient received 0.5µg/kg fentanyl (iv).The patient was administered a loading dose of dexmedetomidine 0.5 μg/kg-1 over 10 minutes. Propofol 0.1 μg/kg bolus was administered to patients as needed.
Other Names:
  • D Group

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Assessment of Cognitive Function
Time Frame: Baseline (pre-procedure), 2 hours post-procedure, and 24 hours post-procedure

Change in cognitive function assessed by Mini Mental State Examination scores. Mini Mental State Examination scores can be between 0-30.

>10 severe impairment, 10-19 moderate dementia 19-24 early dementia 25 ≤normal
Baseline (pre-procedure), 2 hours post-procedure, and 24 hours post-procedure

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Frailty Score
Time Frame: Baseline (pre-procedure)

Frailty was assessed using the Clinical Frailty Scale prior to colonoscopy. Frail scores can be between 0-5.

O normal, 1-2 Pre-frail, 3-5 Frail
Baseline (pre-procedure)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Ankara City Hospital Bilkent

Investigators

  • Principal Investigator: Filiz Kaya, M.D., Ankara City Hospital Bilkent

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 1, 2023

Primary Completion (Actual)

January 15, 2024

Study Completion (Actual)

January 15, 2024

Study Registration Dates

First Submitted

January 27, 2026

First Submitted That Met QC Criteria

January 27, 2026

First Posted (Actual)

February 3, 2026

Study Record Updates

Last Update Posted (Actual)

February 10, 2026

Last Update Submitted That Met QC Criteria

February 6, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • E2-23-4566

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

The investigators plan to share results after published for one year

IPD Sharing Time Frame

one year

IPD Sharing Access Criteria

researchers

IPD Sharing Supporting Information Type

  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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