Clinical trial NCT06490588: Use of Sevoflurane to Test Concept of Cognitive Reserve
Official title: 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
Study type: OBSERVATIONAL
Overall status: NOT_YET_RECRUITING
Conditions: Cognitive Reserve
BIS
Lead sponsor: Los Angeles General Medical Center
Sponsor class: OTHER
First posted: 2024-07-08
Enrollment: 70
Sex: ALL
Minimum age (years): 18
Maximum age (years): 90
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: ASA I or II

Brief summary: 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.

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.

Eligibility criteria: 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

Primary outcomes:
measure: intraoperative BIS variability
timeFrame: 360 minutes
Secondary outcomes:
measure: time to recovery
timeFrame: 120 minutes
Other outcomes:
Locations:
Study officials:
References:
citation: 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.