Clinical trial NCT04062240: Bispectral Index: A Comparison of Bifrontal Montage Agreement
Official title: Bispectral Index: A Comparison of Bifrontal Montage Agreement
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Surgery
Bispectral Index
Keywords: BIS
Bispectral Index
Paralysis
Lead sponsor: Mayo Clinic
Sponsor class: OTHER
First posted: 2019-08-20
Enrollment: 15
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_CONTROL
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: The study population consists of adult patients undergoing elective cardiac surgery, for whom BIS monitoring will be used.

Brief summary: The researchers are trying to compare the results of two sensors when recorded simultaneously on opposite sides of the forehead.

Detailed description: Bispectral Index (BIS) monitors are FDA approved to gauge depth of sedation by analyzing segments of electroencephalogram (EEG) waves. The BIS monitor utilizes a proprietary algorithm to process the EEG information second by second, and outputs a number (0-100) that corresponds with a patient's level of consciousness. A level of 0 indicates no EEG activity; a level of 100 indicates awake EEG activity. Several studies demonstrated that BIS monitors may not be useful in paralyzed patients, as patients who were paralyzed and not sedated unexpectedly showed a large decrease in their BIS values following administration paralytic medications. Vivien et al found BIS values dropped an average of 24 points in already sedated patients when the patients were given paralytics. In the same year, Messner and colleagues paralyzed non-sedated volunteers and found a dramatic drop in BIS values until paralysis wore off or was reversed. Schuller et al repeated the Messner experiment and found similar results with 18 of 20 non-sedated volunteer's BIS values dropping to levels expected of patients who were sedated. These results suggest that BIS monitors are integrating electromyography (EMG) data into its algorithm to derive a BIS value. Our hypothesis is that a BIS monitor commenced after paralysis, thereby lacking exposure to any "awake" EMG activity, will result in a cleaner data set and more accurate representation of a patient's level of sedation. Studying in this manner will require the subject to wear two BIS sensors in a frontal montage. The manufacturer of the sensors gives no guidance as to which side of the forehead an individual sensor is placed, and no studies demonstrate BIS validity with the use of concurrent sensors. The purpose of the present investigation is to assess the measurement difference and variability associated with use of concurrent bifrontal BIS sensors. The data obtained will be used as a framework for a future study related to the use of paralytics and BIS monitoring.

Eligibility criteria: Inclusion Criteria:

1. Adult patient having elective cardiac surgery

Exclusion Criteria:

1. Patient refusal.
2. Pediatric patients.
3. Emergency procedure.
4. Patients with known or suspected carotid or cerebrovascular disease.
5. Patients with prior stroke.
6. Skin condition or anatomy preventing proper sensor placement.

Primary outcomes:
measure: BIS Montage
timeFrame: 10 minutes where both sensors are recording concurrently
Secondary outcomes:
measure: Ketamine
timeFrame: 10 minutes where both sensors are recording concurrently
Other outcomes:
Locations:
city: Rochester
country: United States
facility: Mayo Clinic
state: Minnesota
Study officials:
affiliation: Mayo Clinic
name: Matthew Ritter, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Messner M, Beese U, Romstock J, Dinkel M, Tschaikowsky K. The bispectral index declines during neuromuscular block in fully awake persons. Anesth Analg. 2003 Aug;97(2):488-491. doi: 10.1213/01.ANE.0000072741.78244.C0.
citation: Schuller PJ, Newell S, Strickland PA, Barry JJ. Response of bispectral index to neuromuscular block in awake volunteers. Br J Anaesth. 2015 Jul;115 Suppl 1:i95-i103. doi: 10.1093/bja/aev072.
citation: Vivien B, Di Maria S, Ouattara A, Langeron O, Coriat P, Riou B. Overestimation of Bispectral Index in sedated intensive care unit patients revealed by administration of muscle relaxant. Anesthesiology. 2003 Jul;99(1):9-17. doi: 10.1097/00000542-200307000-00006.