Cognitive Function in Geriatric Colonoscopy Patients

Overview

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.

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.