Bispectral Index: A Comparison of Bifrontal Montage Agreement

Surgery Clinical Trial

Official title:

Bispectral Index: A Comparison of Bifrontal Montage Agreement

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04062240
• Other study ID #: 19-000568
• Status: Completed
• Start date: November 27, 2019
• Est. completion date: October 1, 2021

Study information

• Verified date: May 2022
• Source: Mayo Clinic
• Contact: n/a
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

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

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 15
• Est. completion date: October 1, 2021
• Est. primary completion date: June 1, 2021
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

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.

Related Conditions & MeSH terms

• Bispectral Index
• Surgery

Intervention

Device:
• BIS sensor
BIS sensors will be labeled L and R. The degree of variability between the concurrent use of the sensors will be assessed .

Locations

Country	Name	City	State
United States	Mayo Clinic	Rochester	Minnesota

Sponsors (1)

Lead Sponsor	Collaborator
Mayo Clinic

Country where clinical trial is conducted

United States, 

References & Publications (3)

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. — View 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. — View 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- — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	BIS Montage	Degree of variability between the values produced by the BIS sensors in a bifrontal montage when monitored simultaneously by use of a Bland-Altmann plot. The average value of each timed pair was plotted against the difference between the pairs.; The BIS monitor outputs data on a scale of 0-100 in arbitrary units; 0 = an isoelectric state on EEG, 100 = fully awake patient. BIS values of 40-60 are thought to reduce the chance of patient recall during general anesthesia.; For the purpose of this study, a smaller confidence interval is better as it indicates a higher level of agreement between the two BIS sensors.	10 minutes where both sensors are recording concurrently
Secondary	Ketamine	Degree to which Ketamine may influence BIS values	10 minutes where both sensors are recording concurrently

External Links

•   Mayo Clinic Clinical Trials