Use of Sevoflurane to Test Concept of Cognitive Reserve

The Use of Sevoflurane to Test the Concept of Intra-individual Variability in Bispectral Index Monitor and Cognitive Reserve by Examining Time to Emergence and Recovery

Previous pilot study had demonstrated a correlation between cognitive reserve and BIS variability during steady state of anesthesia. This study, we intend to evaluate the association between BIS variability and emergence and recovery time from anesthesia.

Study Overview

• Status: Not yet recruiting
• Conditions: BIS; Cognitive Reserve
• Intervention / Treatment: Other: sevoflurane

Detailed Description

Cognitive reserve (CR) refers to an individual's ability to resist damage to the brain and is thought to be associated with an individual's education, cognitive stimulation, and physical activity. Those with greater CR have protection against degenerative brain changes such as dementia. Currently, CR is evaluated through a host of proxy tests such as questionnaires aimed to assess various aspects of cognitive function. These ways of measuring CR test directly only on an individual's ability to perform certain tasks when the brain is in its "unchallenged" state. However, this approach poses significant limitations since CR is developed as a concept representing the physiological brain reserve that helps counter the clinical manifestation of a diseased or "challenged" brain. A method that simulates a state of "challenged" brain during CR measurement may provide a more precise assessment of CR.

Anesthetic agents are known to reversibly alter brain function resulting in a state of sedation or amnesia. Whether this way of brain "challenge" can provide information on CR is unknown.

A previous study showed preliminary evidence that patients with higher CR correlates with less variability in bispectral index (BIS) during steady state of anesthesia with inhaled anesthetic sevoflurane (1). While the result of this study is encouraging, further study is needed to develop the concept of using anesthetic agents to evaluate CR. Specifically, a study investigating the correlation between intraoperative BIS variability and timing of clinical recovery from anesthesia will be necessary. This will further elucidate how to use anesthetic agent for the evaluation of CR.

Building on the previous study result and the concept that higher CR means higher resilience against brain function in a "challenged" state, we hypothesize that less intraoperative BIS variability correlates with shorter recovery time from anesthesia.

• Study Type: Observational
• Enrollment (Estimated): 70

Contacts and Locations

• Study Contact: Name: Jody Chou, MD, MPH; Phone Number: 949-310-7024; Email: cchou@dhs.lacounty.gov

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Probability Sample

Study Population

ASA I or II

Description

Inclusion Criteria:

• - Minimal completion of high-school education
• Adult patient < 85 years of age
• No prior known history of cognitive/brain disease
• ASA class I-II
• Undergoing general anesthesia with sevoflurane for maintenance anesthesia
• Same-day surgery
• Elective procedures
• No prior history of cardiac disease

Exclusion Criteria:

• - History of chronic pain
• Perioperative use of anesthetic agents other than propofol, fentanyl, dilaudid, and sevoflurane
• History of alcohol/substance druge abuse
• Psychiatric history
• Morbid history
• History of OSA, stroke, or TIA
• Blindness
• Deafness

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
intraoperative BIS variability	360 minutes

Secondary Outcome Measures

Outcome Measure	Time Frame
time to recovery	120 minutes

Collaborators and Investigators

• Sponsor: Los Angeles General Medical Center

Publications and helpful links

General Publications

• Hernaiz Alonso C, Tanner JJ, Wiggins ME, Sinha P, Parvataneni HK, Ding M, Seubert CN, Rice MJ, Garvan CW, Price CC. Proof of principle: Preoperative cognitive reserve and brain integrity predicts intra-individual variability in processed EEG (Bispectral Index Monitor) during general anesthesia. PLoS One. 2019 May 23;14(5):e0216209. doi: 10.1371/journal.pone.0216209. eCollection 2019.

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2024
• Primary Completion (Estimated): April 1, 2025
• Study Completion (Estimated): September 1, 2026

Study Registration Dates

• First Submitted: June 25, 2024
• First Submitted That Met QC Criteria: June 28, 2024
• First Posted (Actual): July 8, 2024

Study Record Updates

• Last Update Posted (Actual): July 8, 2024
• Last Update Submitted That Met QC Criteria: June 28, 2024
• Last Verified: June 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Central Nervous System Depressants; Anesthetics, General; Anesthetics; Platelet Aggregation Inhibitors; Anesthetics, Inhalation; Sevoflurane
• Other Study ID Numbers: HS-22-00653

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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