Anesthetic Agent Titration With EEG Wave Analysis

Anesthetic Agent Titration With EEG Wave Analysis: Does it Improve Postoperative Recovery?

Several studied shown that when general anesthesia is applied under BIS guidance, anesthetic doses are reduced. Additionally it has been found that the risk of postoperative delirium (POD) is reduced and postoperative recovery is accelerated compared to deeper general anesthesia. Current guidelines recommend EEG-based monitoring techniques to prevent postoperative neurocognitive disorders. In clinical practice anesthetic depth is assessed by the patient's autonomic responses to surgical stimulation (pupil diameter, tear, blood pressure and heart rate increase, etc.), the amount of anesthetic gas measured from the expiratory air, and the interpretation of EEG waves and numerical values calculated from these waves (bispactral index, entropy, patient safety index, etc.). The doses of intravenous anesthetic agents used for anesthesia induction are traditionally determined according to body weight. If general anesthetic doses cannot be titrated appropriately for the patients, especially in the elderly and fragile patient group, serious hemodynamic fluctuations may occur during anesthesia induction. The aim of this study is to investigate whether induction and maintenance of anesthesia using the Kugler EEG Analysis method would improve the quality of postoperative recovery in patients aged 65 years and older.

Study Overview

• Status: Completed
• Conditions: EEG Data Analysis; Geriatric Patient Care Improvement

Detailed Description

Several studied shown that when general anesthesia is applied under BIS guidance, anesthetic doses are reduced. Additionally it has been found that the risk of postoperative delirium (POD) is reduced and postoperative recovery is accelerated compared to deeper general anesthesia. Current guidelines recommend EEG-based monitoring techniques to prevent postoperative neurocognitive disorders. In clinical practice anesthetic depth is assessed by the patient's autonomic responses to surgical stimulation (pupil diameter, tear, blood pressure and heart rate increase, etc.), the amount of anesthetic gas measured from the expiratory air, and the interpretation of EEG waves and numerical values calculated from these waves (bispactral index, entropy, patient safety index, etc.). The doses of intravenous anesthetic agents used for anesthesia induction are traditionally determined according to body weight. If general anesthetic doses cannot be titrated appropriately for the patients, especially in the elderly and fragile patient group, serious hemodynamic fluctuations may occur during anesthesia induction. The aim of this study is to investigate whether induction and maintenance of anesthesia using the Kugler EEG Analysis method would improve the quality of postoperative recovery in patients aged 65 years and older.

• Study Type: Observational
• Enrollment (Actual): 200

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Istanbul, Turkey (Türkiye)
    • Marmara University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

65 years and older patients

Description

Inclusion Criteria:

• Patients aged 65 and over
• Elective patients undergoing general anesthesia
• EEG monitoring

Exclusion Criteria:

• Pediatric patients
• Patients not giving written consent
• Emergency cases
• History of seizure
• Intracranial surgeries
• Alcohol and substance addiction
• Severe cognitive impairment (dementia, Alzheimer's)

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Conventional Anesthetic Management; Preoperatively, patients were administered the QoR-15 questionnaire and scoring was done according to the Nu-DESC test. Before anesthesia induction, patients will be taught the finger-squeeze test and asked to squeeze the fingers placed in the palm when instructed. If no response is obtained to the test after routine administration of 2 mg/kg propofol and 1.5 mcg/kg fentanyl; 0,5 mg/kg rokuronium administered. Desflurane will be used as maintenance inhalation agent. Hemodynamic parameters and burst suppression time will be recorded at 5-minute intervals during the first 15 minutes after induction and at 15-minute intervals thereafter. At the end of the surgery, the patient will be ready to be sent to the ward with the Modified Aldrete score, and awareness will be assessed with the Modified Brice scale. The QoR-15 questionnaire was repeated at 24 hours postoperatively. For delirium assessment, patients were followed up with the Nu-DESC test for 48 hours postoperatively.
Anesthetic Management with Kugler EEG method; Preoperatively, patients were administered the QoR-15 questionnaire and scoring was done according to the Nu-DESC test. Before anesthesia induction, patients will be taught the finger-squeeze test and asked to squeeze the fingers placed in the palm when instructed.Patients were administered propofol according to the Kugler EEG analysis (to be kept C-D level) If no response is obtained, fentanyl 1,5 mcg/kg, 0,5 mg/kg rocuronium administered. Desflurane will be used as maintenance inhalation agent. Hemodynamic parameters and burst suppression time will be recorded at 5-minute intervals during the first 15 minutes after induction and at 15-minute intervals thereafter. At the end of the surgery, the patient ready to be sent to the ward with the Modified Aldrete score, and awareness will be assessed with the Modified Brice scale. The QoR-15 questionnaire repeated at 24 hours postoperatively. For delirium assessment, patients followed up with the Nu-DESC test for 48 hours postoperatively.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative Recovery Quality	Data of QoR-15 score in the preoperative period and at the 24th hour postoperatively The 15-item Quality of Recovery (QoR-15) score is a patient-reported outcome measure assessing postoperative recovery. Scores range from 0 to 150, with higher scores indicating better quality of recovery.	24 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative Delirium Evaluation	Nu-DESC score in the preoperative period and 48-hour postoperative period The Nursing Delirium Screening Scale (Nu-DESC) is a clinician-rated tool used to screen for delirium. The total score ranges from 0 to 10, with higher scores indicating a worse outcome (greater severity or presence of delirium).	48 hours

Collaborators and Investigators

• Sponsor: Marmara University

Study record dates

Study Major Dates

• Study Start (Actual): March 4, 2025
• Primary Completion (Actual): November 4, 2025
• Study Completion (Actual): November 4, 2025

Study Registration Dates

• First Submitted: November 24, 2025
• First Submitted That Met QC Criteria: November 24, 2025
• First Posted (Estimated): December 5, 2025

Study Record Updates

• Last Update Posted (Actual): December 19, 2025
• Last Update Submitted That Met QC Criteria: December 14, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: electroencephalogram; postoperative delirium; geriatric patients
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Mental Disorders; Postoperative Complications; Pathologic Processes; Confusion; Neurobehavioral Manifestations; Neurocognitive Disorders; Delirium; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Emergence Delirium
• Other Study ID Numbers: 09.2025.25-0113

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No