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

NCT00689091 | Completed Results DMC

• 1 other identifier: HUM00013626
• Study Type: interventional
• Target: 22,185
• Locations: 1 country
• Sites: 1

Brief 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

Keywords

Awareness; BIS Monitor; electronic alerts; minimum; alveolar; concentration

Outcome Measures

Primary Outcomes (1)

• The Percentage of Incidences With Explicit Recall in the BIS Versus MAC Alert Groups.

  By modified intention-to-treat analysis

  Outcome of awareness is assessed 30-days after the operation

Secondary Outcomes (6)

• Number of Participants With Dreams During Anesthesia Compared Between MAC or BIS Monitoring

  During surgery (45 minutes - 18 hours), measured based on 30 day interviews

• Percentage of Cases With Electronic Alerts

  During surgery: (45 minutes - 18 hours)

• Overall Use of Anesthetics Comparing the BIS to MAC Alerts.

  During surgery (45 minutes - 18 hours)

• Time Till Discharge Readiness

  During recovery room stay: 30 minutes to 6 hours

• Number of Participants Without Nausea or Vomiting

  During recovery room stay: 30 minutes to 6 hours

Other Outcomes (6)

• Relationship Between BIS Values and Hemodynamic Parameters.

  Outcome of hemodynamic stability is assessed

• The Relationship Between Cumulative Deep Hypnotic Time, Anesthetic Doses, and Mortality.

  Outcome of mortality is assessed

• Predictors of Post-traumatic Stress Disorder Based on the Type of Awareness Event.

  Outcome of post-traumatic stress disorder is assessed with the covariate of awareness

Study Arms (2)

BIS group

EXPERIMENTAL

This group will have BIS values visible and will receive alerts when the value is \>60.

Device: Bispectral Index Monitor

MAC Alert

ACTIVE COMPARATOR

This group will receive an alert if total MAC (including intravenous infusions) is \<0.5 age-adjusted.

Device: Electronic MAC alert

Interventions

Bispectral Index Monitor DEVICE

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

BIS group

Electronic MAC alert DEVICE

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

MAC Alert

Eligibility Criteria

• Age: 18 Years - 100 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• At least 18 years of age, English-speaking, available for follow-up interview at one month.

You may not qualify if:

• Pre-existing neurologic or neuropsychiatric condition, surgical manipulation around forehead, not available for follow-up interview.

Sponsors & Collaborators

• University of Michigan: lead
• Foundation for Anesthesia Education and Research: collaborator
• American Society of Anesthesiologists: collaborator
• Washington University School of Medicine: collaborator
• University of Chicago: collaborator
• University of Manitoba: collaborator

Study Sites (1)

University of Michigan Medical School, University Hospital

Ann Arbor, Michigan, 48109, United States

Location

Related Publications (4)

• Vance JL, Shanks AM, Woodrum DT. Intraoperative bispectral index monitoring and time to extubation after cardiac surgery: secondary analysis of a randomized controlled trial. BMC Anesthesiol. 2014 Sep 18;14:79. doi: 10.1186/1471-2253-14-79. eCollection 2014.

  PMID: 25249789 DERIVED

• Shanks AM, Avidan MS, Kheterpal S, Tremper KK, Vandervest JC, Cavanaugh JM, Mashour GA. Alerting thresholds for the prevention of intraoperative awareness with explicit recall: a secondary analysis of the Michigan Awareness Control Study. Eur J Anaesthesiol. 2015 May;32(5):346-53. doi: 10.1097/EJA.0000000000000123.

  PMID: 25010744 DERIVED

• Avidan MS, Palanca BJ, Glick D, Jacobsohn E, Villafranca A, O'Connor M, Mashour GA; BAG-RECALL Study Group. Protocol for the BAG-RECALL clinical trial: a prospective, multi-center, randomized, controlled trial to determine whether a bispectral index-guided protocol is superior to an anesthesia gas-guided protocol in reducing intraoperative awareness with explicit recall in high risk surgical patients. BMC Anesthesiol. 2009 Nov 30;9:8. doi: 10.1186/1471-2253-9-8.

  PMID: 19948045 DERIVED

• Mashour GA, Tremper KK, Avidan MS. Protocol for the "Michigan Awareness Control Study": A prospective, randomized, controlled trial comparing electronic alerts based on bispectral index monitoring or minimum alveolar concentration for the prevention of intraoperative awareness. BMC Anesthesiol. 2009 Nov 5;9:7. doi: 10.1186/1471-2253-9-7.

  PMID: 19891771 DERIVED

MeSH Terms

Interventions

Consciousness Monitors

Intervention Hierarchy (Ancestors)

Surgical Equipment; Equipment and Supplies

Results Point of Contact

• Title: Dr. George A Mashour
• Organization: University of Michigan

gmashour@med.umich.edu

734-936-4280

Study Officials

• George A. Mashour, M.D., Ph.D.

  University of Michigan

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor of Anesthesiology and Neurosurgery

Study Record Dates

• First Submitted: May 29, 2008
• First Posted: June 3, 2008
• Study Start: May 1, 2008
• Primary Completion: April 1, 2010
• Study Completion: June 1, 2010
• Last Updated: December 7, 2017
• Results First Posted: November 17, 2014

Record last verified: 2017-11

Locations

US (1)