Bispectral Index (BIS) Versus Electronic Alerts in the Prevention of Anesthesia Awareness: the Michigan Awareness Control Study

Summary

Awareness during anesthesia is a problem receiving increased attention by patients, clinicians, and the general public. The incidence of intraoperative awareness has been reported to be between 1-2/1000 cases, but recent data suggest that this may be an overestimate. The Bispectral Index (BIS) Monitor is an electroencephalographic method of assessing depth of anesthesia that has been shown in one study to reduce the incidence of awareness during anesthesia in the high-risk population (Myles et al, 2004). In the study of Myles et al, the number needed to treat (NNT) in order to prevent one case of awareness in the high-risk population was 138, with an associated cost of approximately US$2200. Since the NNT and the associated cost of treatment would be much higher in the general population, the efficacy of the BIS monitor in preventing awareness in all anesthetized patients needs to be clearly established. Furthermore, recent data suggest that the BIS may not be useful in the high-risk population. The investigators propose a prospective, randomized, controlled trial comparing the BIS monitor to electronic alerts based on non-electroencephalographic gauges of anesthetic depth.

Conditions

• Awareness During General Anesthesia

Interventions

DEVICE

Bispectral Index Monitor

Comparison of two different alerting protocols. One using the bispectral index monitor and one using the MAC alerting protocols.

DEVICE

Electronic MAC alert

Comparison of two different alerting protocols. One using the bispectral index monitor and one using the MAC alerting protocols.

Sponsors & Collaborators

• Foundation for Anesthesia Education and Research

  collaborator OTHER

• American Society of Anesthesiologists

  collaborator OTHER

• Washington University School of Medicine

  collaborator OTHER

• University of Chicago

  collaborator OTHER

• University of Manitoba

  collaborator OTHER

• University of Michigan

  lead OTHER

Principal Investigators

• George A. Mashour, M.D., Ph.D. · University of Michigan

Study Design

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

100 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2008-05-31

Primary Completion

2010-04-30

Completion

2010-06-30

Countries

• United States

Study Locations