Intraoperative M-Entropy Measurements

NCT ID: NCT00599066

Last Updated: 2017-04-14

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 24 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2007-09-30
• Study Completion Date: 2009-04-30

Brief Summary

The purpose of this study is to learn more about an Entropy monitor that the anesthesiologist will be using.

Detailed Description

Depth of anesthesia monitors are increasingly used in clinical anesthesia practice. Bispectral Index (BIS) and M-Entropy are examples to these devices, both of which are available at our institution. Both BIS and M-Entropy use a unilateral, single channel of EEG to derive a number indicating the anesthetic depth. These devices have similar disposable skin probes that can be applied on either side of the forehead. Since the depth of anesthesia for an individual is the same over the whole brain cortex at a given point in time, BIS numbers obtained over the left and right side of the forehead should agree. The same should be true for M-Entropy as well.

A recent study, however, showed that two separate BIS probes, applied over the left and right forehead of the same patient at the same time, can give significantly different numbers. This has not been studied for M-Entropy. BIS and M-Entropy use different mathematical algorithms that process the raw EEG signal to compute a numeric value. Therefore, it is possible that M-Entropy may show different results in a similar study setup.

The aim is to investigate the same-patient reproducibility of M-Entropy by monitoring and recording Entropy variables over both the left and the right side of the forehead of patients under general anesthesia.

Conditions

General Anesthesia

Study Design

• Observational Model Type: CASE_ONLY
• Study Time Perspective: PROSPECTIVE

Study Groups

Study cases

Application of a second M-Entropy probe on the forehead of the patient; at the end the patient will have 2 probes on the forehead, one in the right and one in the left.

study cases

Intervention Type: DEVICE

Application of a second M-Entropy probe on the forehead of the patient, which will happen in the OR along with the application of other monitors immediately before induction of general anesthesia.

Interventions

study cases

Application of a second M-Entropy probe on the forehead of the patient, which will happen in the OR along with the application of other monitors immediately before induction of general anesthesia.

Intervention Type: DEVICE

Other Intervention Names

M-entropy module (Datex-Ohmeda S/5 EntropyTM Module)

Eligibility Criteria

Inclusion Criteria

• Patients scheduled to have surgery under general anesthesia, with a minimum of 60 minutes expected duration.

Exclusion Criteria

• Non-English speaker
• Patients younger than 18 years of age

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 90 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University of Oklahoma

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Mehemet Ozcan, MD

Role: PRINCIPAL_INVESTIGATOR

The University of Oklahoma Health Sciences Center, Department of Anesthesiology

Locations

OU MEDICAL CENTER, Presbyterian Tower, OR

Oklahoma City, Oklahoma, United States

Countries

United States

References

Niedhart DJ, Kaiser HA, Jacobsohn E, Hantler CB, Evers AS, Avidan MS. Intrapatient reproducibility of the BISxp monitor. Anesthesiology. 2006 Feb;104(2):242-8. doi: 10.1097/00000542-200602000-00007.

Reference Type: BACKGROUND

PMID: 16436841 (View on PubMed)

Ozcan MS, Gravenstein D. The presence of working memory without explicit recall in a critically ill patient. Anesth Analg. 2004 Feb;98(2):469-470. doi: 10.1213/01.ANE.0000096184.32247.D0.

Reference Type: BACKGROUND

PMID: 14742389 (View on PubMed)

Other Identifiers

IRB No: 13577

Identifier Type: -

Identifier Source: org_study_id