Study Evaluating Whether the Bispectral Index Prevents Patients at Higher Risk From Being Awake During Surgery and Anesthesia

NCT ID: NCT00682825

Last Updated: 2011-01-04

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: PHASE4
• Total Enrollment: 6000 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2008-03-31

Brief Summary

The overall purpose of this study is to see if a Bispectral Index (BIS) monitor, a Food and Drug Administration (FDA) approved brain monitoring device, will help to reduce the risk of patients remembering being awake during surgery. The BIS monitor may be able to measure how asleep a patient is during surgery. Using the BIS monitor to guide anesthesia will be compared with using the concentration of anesthetic gas to guide anesthesia.

Detailed Description

The incidence of anesthesia awareness (AA) is 0.1-0.2% and may result in post traumatic stress disorders. For some patients, owing to illness, medications, substance misuse or surgery, the risk approaches 1%. The B-AWARE Study by Myles et al. suggested that the bispectral index (BIS) monitor, which reportedly reflects anesthetic depth, may decrease the incidence of AA in higher risk patients by 82%. The American Society of Anesthesiologists has published a practice advisory on AA, which does not recommend the routine use of cerebral function monitors. We propose to test the hypothesis that an anesthetic protocol based on BIS decreases the incidence of AA among higher risk patients compared with an anesthetic protocol based on the end-tidal anesthetic gas (ETAG) concentration. We have completed a randomized, single-blinded prospective feasibility study (The B-Unaware Trial) which enrolled 2000 patients at higher risk for AA. Four patients (0.21%; 95% CI=0.06% to 0.57%) had definite AA, of whom two were in the BIS-guided group and two in the ETAG-guided group. Nine patients (0.46%; 95% CI=0.22% to 0.91%) had definite or possible AA, of whom six were in the BIS-guided group and three in the ETAG-guided group. The BAG RECALL study will be a multi-center, prospective, single-blinded, randomized study enrolling 6000 patients at higher risk for AA. The BAG RECALL study is adequately powered and rigorously designed to answer with a reasonable degree of scientific probability whether BIS guidance results in clinically relevant reduction in anesthesia awareness among higher risk patients undergoing general anesthesia.

At the University of Michigan, a parallel study will be conducted - Michigan Awareness Control Study, MACS (NCT00689091) - enrolling 30,000 patients to assess whether the BIS monitor decreases the likelihood of anesthesia awareness among all patients undergoing general anesthesia, regardless of their risk profile. The investigators of this study and the BAG-RECALL study have collaborated in designing these studies and are pre-specifying that common outcome measures will be examined collaboratively including data from both studies.

Conditions

Explicit Recall of Intra-Operative Events

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: TRIPLE

Study Groups

1

Bispectral index-guided protocol

Group Type: EXPERIMENTAL

Bispectral index protocol

Intervention Type: BEHAVIORAL

Aim to titrate anesthesia to maintain BIS between 40 and 60.

2

End-tidal anesthetic gas-guided protocol

Group Type: ACTIVE_COMPARATOR

End tidal anesthetic gas-guided

Intervention Type: BEHAVIORAL

Aim to maintain anesthetic gas between 0.7 and 1.3 MAC equivalents

Interventions

Bispectral index protocol

Aim to titrate anesthesia to maintain BIS between 40 and 60.

Intervention Type: BEHAVIORAL

End tidal anesthetic gas-guided

Aim to maintain anesthetic gas between 0.7 and 1.3 MAC equivalents

Intervention Type: BEHAVIORAL

Eligibility Criteria

Inclusion Criteria

MUST HAVE:

General Anesthesia with volatile anesthetic

PATIENT CHARACTERISTICS

Major Criteria (Must have any 1 of the following:)

1. Planned open heart surgery

2. Medications - anticonvulsants, abuse of opiates, benzodiazepines, cocaine

3. EF<40%

4. Prior history of awareness (recall)

5. History of difficult intubation or anticipated difficult intubation

6. ASA IV or V status

7. Aortic stenosis

8. End stage lung disease

9. Marginal exercise tolerance not secondary to musculoskeletal dysfunction

10. Pulmonary hypertension

11. Daily alcohol consumption

Exclusion Criteria

1. Surgical procedure that prevents the use of the BIS (e.g. surgery of forehead)

2. Patient positioning prevents use of the BIS

3. Surgery with wake-up test.

4. Less than 18 years of age

5. Vulnerable populations, such as those with dementia and those unable to provide informed consent.

6. Stroke with residual neurological deficits

-

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

Sponsors

Foundation for Anesthesia Education and Research

OTHER

Sponsor Role: collaborator

American Society of Anesthesiologists

OTHER

Sponsor Role: collaborator

University of Chicago

OTHER

Sponsor Role: collaborator

University of Manitoba

OTHER

Sponsor Role: collaborator

University of Michigan

OTHER

Sponsor Role: collaborator

Washington University School of Medicine

OTHER

Sponsor Role: lead

Responsible Party

Washington University

Principal Investigators

Michael S Avidan, MBBCh FCA

Role: PRINCIPAL_INVESTIGATOR

Washington University School of Medicine

David Glick, MD

Role: STUDY_DIRECTOR

University of Chicago

Eric Jacobsohn, MBChB

Role: STUDY_CHAIR

University of Manitoba

Michael O'Connor, MD

Role: STUDY_DIRECTOR

University of Chicago

Alex S Evers, MD

Role: STUDY_CHAIR

Washington University School of Medicine

Locations

University of Chicago

Chicago, Illinois, United States

Washington University

St Louis, Missouri, United States

University of Manitoba

Winnipeg, Manitoba, Canada

Countries

United States; Canada

References

Myles PS, Leslie K, McNeil J, Forbes A, Chan MT. Bispectral index monitoring to prevent awareness during anaesthesia: the B-Aware randomised controlled trial. Lancet. 2004 May 29;363(9423):1757-63. doi: 10.1016/S0140-6736(04)16300-9.

Reference Type: BACKGROUND

PMID: 15172773 (View on PubMed)

Avidan MS, Zhang L, Burnside BA, Finkel KJ, Searleman AC, Selvidge JA, Saager L, Turner MS, Rao S, Bottros M, Hantler C, Jacobsohn E, Evers AS. Anesthesia awareness and the bispectral index. N Engl J Med. 2008 Mar 13;358(11):1097-108. doi: 10.1056/NEJMoa0707361.

Reference Type: BACKGROUND

PMID: 18337600 (View on PubMed)

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.

Reference Type: BACKGROUND

PMID: 19948045 (View on PubMed)

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.

Reference Type: BACKGROUND

PMID: 19891771 (View on PubMed)

Mashour GA, Esaki RK, Tremper KK, Glick DB, O'Connor M, Avidan MS. A novel classification instrument for intraoperative awareness events. Anesth Analg. 2010 Mar 1;110(3):813-5. doi: 10.1213/ANE.0b013e3181b6267d. Epub 2009 Aug 27.

Reference Type: BACKGROUND

PMID: 19713251 (View on PubMed)

Willingham M, Ben Abdallah A, Gradwohl S, Helsten D, Lin N, Villafranca A, Jacobsohn E, Avidan M, Kaiser H. Association between intraoperative electroencephalographic suppression and postoperative mortality. Br J Anaesth. 2014 Dec;113(6):1001-8. doi: 10.1093/bja/aeu105. Epub 2014 May 22.

Reference Type: DERIVED

PMID: 24852500 (View on PubMed)

Whitlock EL, Torres BA, Lin N, Helsten DL, Nadelson MR, Mashour GA, Avidan MS. Postoperative delirium in a substudy of cardiothoracic surgical patients in the BAG-RECALL clinical trial. Anesth Analg. 2014 Apr;118(4):809-17. doi: 10.1213/ANE.0000000000000028.

Reference Type: DERIVED

PMID: 24413548 (View on PubMed)

Avidan MS, Jacobsohn E, Glick D, Burnside BA, Zhang L, Villafranca A, Karl L, Kamal S, Torres B, O'Connor M, Evers AS, Gradwohl S, Lin N, Palanca BJ, Mashour GA; BAG-RECALL Research Group. Prevention of intraoperative awareness in a high-risk surgical population. N Engl J Med. 2011 Aug 18;365(7):591-600. doi: 10.1056/NEJMoa1100403.

Reference Type: DERIVED

PMID: 21848460 (View on PubMed)

Related Links

http://www.clinicaltrials.gov/ct2/show/NCT00689091

Bispectral Index (BIS) Versus Electronic Alerts in the Prevention of Awareness (MACS)

Other Identifiers

07-1253

Identifier Type: -

Identifier Source: org_study_id