The Effects of Anesthesia Depth Monitoring on Postoperative Recovery and Cognitive Functions in the Geriatric Patient Population

Official title

Geriatrik Hasta Grubunda Anestezi Derinliği Monitörizasyonlarının Postoperatif Derlenme ve Bilişsel Fonksiyonlara Etkileri

Overview

This study will be conducted on patients aged 65 and older scheduled for surgery due to lumbar or cervical disc herniation. General anesthesia is routinely used for these types of surgeries in the hospital. In patients receiving general anesthesia, anesthesia depth monitoring is performed. As part of the study, a preoperative anesthesia evaluation will be conducted, which will include age, weight, height, comorbidities, regularly used medications, previous surgical or anesthesia experiences, nutritional habits, mental status, and daily activity levels. On the day of surgery, upon arrival in the operating room, the following will be measured and recorded: * Blood pressure using a non-invasive blood pressure monitor * Heart rate and rhythm via electrocardiogram (ECG) * Blood oxygen level with a pulse oximeter * Anesthesia depth using a forehead-applied sensor All monitoring procedures are non-invasive and painless. Following the placement of these monitoring devices and initial measurements, anesthesia induction and surgery will commence. Throughout surgery, blood pressure, heart rate, and brain activity will be continuously recorded. After the surgical procedure, anesthesia emergence and mental status will be assessed. Preoperative evaluation data and intraoperative recordings will be used solely for research purposes, with patient identity information remaining confidential.

Detailed description

Perioperative cognitive decline and delirium occur more frequently in the geriatric population undergoing surgery. International guidelines recommend monitoring anesthesia depth to reduce the risk of postoperative cognitive dysfunction. Anesthesia depth is commonly measured using non-invasive electroencephalography (EEG)-based methods, such as the Bispectral Index (BIS).

Previous studies have predominantly utilized processed EEG monitors that generate numerical values for tracking anesthesia depth. However, in this study, anesthesia depth will be monitored using both the standard numerical BIS index and the Density Spectral Array (DSA) mode, an advanced feature of the BIS device. To date, no studies have simultaneously examined BIS and DSA modes in relation to cognitive function and the recovery process.

The use of advanced monitoring techniques may serve as a valuable resource for future research, particularly in optimizing anesthetic management for geriatric patients with reduced cognitive reserve. This study aims to evaluate the effects of different intraoperative anesthesia depth monitoring approaches, including hemodynamic monitoring, numerical BIS values, and DSA functions. The primary objective is to determine the optimal anesthesia monitoring strategy that minimizes intraoperative hypotension, burst suppression, and postoperative delirium.

Interventions

• Other Control Group: Standard Hemodynamic Monitoring
  Anesthesia depth monitoring based on hemodynamic values without additional processed EEG guidance.
• Device Processed Electroencephalogram (BIS Index)
  Anaesthesia depth monitoring according to numeric BIS index values.
• Device Processed Electroencephalogram (DSA Mode)
  Anaesthesia depth monitoring according to density spectral array functions

Primary outcome measures

• Ratio of Burst Suppression [Time frame: Intraoperative (continuously recorded from anesthesia induction to emergence)]
• Time of Burst Suppression [Time frame: Intraoperative (continuously recorded from anesthesia induction to emergence)]
• Intraoperative Hypotension Incidence [Time frame: Intraoperative (assessed continuously throughout surgery)]
• Alpha Band Preservation or Loss [Time frame: Intraoperative (measured continuously from anesthesia induction to emergence)]

Secondary outcome measures (5)

• Incidence of Postoperative Delirium Assessed via CAM Scale [Time frame: Postoperative (assessed at 6, 24, and 48 hours after surgery)]
• Total Intraoperative Propofol Consumption [Time frame: Intraoperative]
• Total Intraoperative Sevoflurane Consumption [Time frame: Intraoperative]
• Total Intraoperative Remifentanil Consumption [Time frame: Intraoperative]
• Total Intraoperative Vasopressor Consumption [Time frame: Intraoperative]

Eligibility criteria

Inclusion criteria

• 65 years and older
• Elective spinal surgeries
• ASA status I-III

Exclusion criteria

• Emergent surgeries
• ASA status IV-V
• Prediagnosed delirium and or dementia
• Inability to give consent

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Triple blind

Primary purpose

Prevention

Study locations

Turkey (Türkiye) · 1 center

• Gazi University School of Medicine — Ankara

Publications

• Purdon PL, Sampson A, Pavone KJ, Brown EN. Clinical Electroencephalography for Anesthesiologists: Part I: Background and Basic Signatures. Anesthesiology. 2015 Oct;123(4):937-60. doi: 10.1097/ALN.0000000000000841. PMID 26275092
• Aldecoa C, Bettelli G, Bilotta F, Sanders RD, Audisio R, Borozdina A, Cherubini A, Jones C, Kehlet H, MacLullich A, Radtke F, Riese F, Slooter AJ, Veyckemans F, Kramer S, Neuner B, Weiss B, Spies CD. European Society of Anaesthesiology evidence-based and consensus-based guideline on postoperative delirium. Eur J Anaesthesiol. 2017 Apr;34(4):192-214. doi: 10.1097/EJA.0000000000000594. PMID 28187050
• Wildes TS, Mickle AM, Ben Abdallah A, Maybrier HR, Oberhaus J, Budelier TP, Kronzer A, McKinnon SL, Park D, Torres BA, Graetz TJ, Emmert DA, Palanca BJ, Goswami S, Jordan K, Lin N, Fritz BA, Stevens TW, Jacobsohn E, Schmitt EM, Inouye SK, Stark S, Lenze EJ, Avidan MS; ENGAGES Research Group. Effect of Electroencephalography-Guided Anesthetic Administration on Postoperative Delirium Among Older Adu PMID 30721296
• Chen YC, Hung IY, Hung KC, Chang YJ, Chu CC, Chen JY, Ho CH, Yu CH. Incidence change of postoperative delirium after implementation of processed electroencephalography monitoring during surgery: a retrospective evaluation study. BMC Anesthesiol. 2023 Oct 4;23(1):330. doi: 10.1186/s12871-023-02293-9. PMID 37794315
• Shao YR, Kahali P, Houle TT, Deng H, Colvin C, Dickerson BC, Brown EN, Purdon PL. Low Frontal Alpha Power Is Associated With the Propensity for Burst Suppression: An Electroencephalogram Phenotype for a "Vulnerable Brain". Anesth Analg. 2020 Nov;131(5):1529-1539. doi: 10.1213/ANE.0000000000004781. PMID 33079876
• Fritz BA, Kalarickal PL, Maybrier HR, Muench MR, Dearth D, Chen Y, Escallier KE, Ben Abdallah A, Lin N, Avidan MS. Intraoperative Electroencephalogram Suppression Predicts Postoperative Delirium. Anesth Analg. 2016 Jan;122(1):234-42. doi: 10.1213/ANE.0000000000000989. PMID 26418126
• Monk TG, Weldon BC, Garvan CW, Dede DE, van der Aa MT, Heilman KM, Gravenstein JS. Predictors of cognitive dysfunction after major noncardiac surgery. Anesthesiology. 2008 Jan;108(1):18-30. doi: 10.1097/01.anes.0000296071.19434.1e. PMID 18156878

Identifiers

NCT: NCT06844279 · Gazi-2024 -1816

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗