Measurement of Bispectral Index and Awareness in Patients Undergoing Electrophysiology Studies With Isoproterenol

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
New York University School of Medicine
ClinicalTrials.gov Identifier:
NCT01377636
First received: March 22, 2010
Last updated: July 29, 2013
Last verified: July 2013
  Purpose

Isoproterenol is used as a cardiac stimulant in electrophysiology studies (EP). Preliminary data suggests that administration of isoproterenol increases the Bispectral index (BIS). BIS is used to monitor neuronal signals under anesthesia. The BIS level is suggested to correspond to the level of consciousness. We hypothesize that isoproterenol increases BIS values because it increases the patient's level of consciousness through its central nervous system (CNS) stimulatory effects. In this study, we will administer increasing doses of isoproterenol to EPS patients. We will measure the BIS levels continuously before and after isoproterenol administration. In addition, we will test the level of awareness of patients by their response to a modified isolated forearm technique.


Condition Intervention
Intraoperative Awareness
Drug: Isoproterenol

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Study to Measure BIS and Awareness in Patients Undergoing EPS With Isoproterenol

Resource links provided by NLM:


Further study details as provided by New York University School of Medicine:

Primary Outcome Measures:
  • We will measure the BIS level and test the level of awareness of patients by their responses to the isolated forearm technique test before and after isoproterenol administration. [ Time Frame: During time of EP studies. ] [ Designated as safety issue: No ]
    We hypothesize that isoproterenol increases BIS values because it increases the patient's level of consciousness through its central nervous system (CNS) stimulatory effects. In this study, we will administer increasing doses of isoproterenol to EPS patients. We will measure the BIS levels continuously before and after isoproterenol administration. In addition, we will test the level of awareness of patients by their response to the isolated forearm technique.


Enrollment: 25
Study Start Date: August 2009
Study Completion Date: October 2011
Primary Completion Date: September 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Isoproterenol, BIS, forearm test
30 consecutive patients scheduled for EP studies under general anesthesia will participate in the study. Patients with neuromuscular disease precluding the use of succinylcholine will be excluded. The only other exclusions will be patient or cardiologist refusal. No attempts will be made to alter concurrent patient medication.
Drug: Isoproterenol
patients will receive isoproterenol, have a BIS monitoring device and an isolated forearm test.
Other Name: isoprenaline

Detailed Description:

Isoproterenol is a direct acting Beta-1 and Beta-2 agonist useful for its effects on bronchodilation and myocardial contractility. Its CNS side effects include nervousness, headache, dizziness, restlessness, insomnia, anxiety, tension, blurring of vision, fear, and excitement. In addition to our preliminary data, two case reports show an increase in BIS with administration of isoproterenol. Our hypothesis is that administration of isoproterenol will increase the level of consciousness of the patient as reflected in the BIS reading.

The BIS Vista Monitor is a non-invasive device that measures the electrical activity of the brain. It computes a number between 0 and 100 which corresponds to a level of consciousness which is known as the Bispectral (BIS) value. Using the BIS value to guide administration of anesthetic medication, clinicians can make informed decisions for optimal anesthesia. This technology has the potential to prevent over sedation, but is currently not a standard monitoring device.

Another approach to evaluating the level of consciousness of anesthetized patients is to assess their ability to form memories or recall events which occurred while under anesthesia. Conscious recall is the first to disappear with decreasing levels of consciousness. A BIS of 60 or less has been shown in various studies to be sufficient to prevent conscious recall in the vast majority of patients. We propose to use a modified isolated forearm technique test in which the patient is asked to squeeze an observer's hand during anesthesia to ascertain if awareness can occur without recall at a BIS of 60 to 70. (6) Implicit memory in which there is no conscious recall or evaluation of awareness can be assessed by word stem completion tests and has been shown to occur with a BIS as low as 40 - 60 although these results are not consistent across all studies. (7)

  Eligibility

Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Patients scheduled for EP studies under general anesthesia will participate in the study

Exclusion Criteria:

  • Patients with neuromuscular disease precluding the use of succinylcholine will be excluded.
  • Patient or cardiologist refusal
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01377636

Locations
United States, New York
NYU Langone Medical Center, Department of Anesthesiology
New York City, New York, United States, 10016
Sponsors and Collaborators
New York University School of Medicine
Investigators
Principal Investigator: Pat Linton, MD NYU School of Medicine
  More Information

No publications provided

Responsible Party: New York University School of Medicine
ClinicalTrials.gov Identifier: NCT01377636     History of Changes
Other Study ID Numbers: H#: 09-0440
Study First Received: March 22, 2010
Last Updated: July 29, 2013
Health Authority: United States: Institutional Review Board

Keywords provided by New York University School of Medicine:
Isoproterenol
Bispectral index (BIS)
electrophysiology studies (EPS)

Additional relevant MeSH terms:
Intraoperative Awareness
Intraoperative Complications
Pathologic Processes
Isoproterenol
Adrenergic Agents
Adrenergic Agonists
Adrenergic beta-Agonists
Anti-Asthmatic Agents
Autonomic Agents
Bronchodilator Agents
Cardiotonic Agents
Cardiovascular Agents
Molecular Mechanisms of Pharmacological Action
Neurotransmitter Agents
Peripheral Nervous System Agents
Pharmacologic Actions
Physiological Effects of Drugs
Protective Agents
Respiratory System Agents
Sympathomimetics
Therapeutic Uses

ClinicalTrials.gov processed this record on October 21, 2014