Intraoperative M-Entropy Measurements

General Anesthesia Clinical Trial

Official title:

Same-patient Reproducibility of Intraoperative M-Entropy Measurements

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00599066
• Other study ID #: IRB No: 13577
• Status: Completed
• Phase: N/A
• First received: December 20, 2007
• Last updated: April 12, 2017
• Start date: September 2007
• Est. completion date: April 2009

Study information

• Verified date: April 2017
• Source: University of Oklahoma
• Contact: n/a
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

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

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 24
• Est. completion date: April 2009
• Est. primary completion date: June 2008
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 90 Years

Eligibility

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

Related Conditions & MeSH terms

• General Anesthesia

Intervention

Device:
• 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.

Locations

Country	Name	City	State
United States	OU MEDICAL CENTER, Presbyterian Tower, OR	Oklahoma City	Oklahoma

Sponsors (1)

Lead Sponsor	Collaborator
University of Oklahoma

Country where clinical trial is conducted

United States, 

References & Publications (2)

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. — View Citation

Ozcan MS, Gravenstein D. The presence of working memory without explicit recall in a critically ill patient. Anesth Analg. 2004 Feb;98(2):469-70, table of contents. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	The investigators hypothesize that simultaneous M-Entropy measurements from the left and right side of the forehead of a person do not differ during general anesthesia.		1 year