Effectiveness of the NeuroSENSE for Monitoring the Hypnotic Depth of Anesthesia

NCT ID: NCT02088671

Last Updated: 2020-02-25

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 76 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2014-06-30
• Study Completion Date: 2016-10-31

Brief Summary

The objective of this clinical study is to investigate whether the NeuroSENSE is an adequate monitor of hypnotic depth-of-anesthesia (DOA). Therefore, this study will investigate whether the information provided by the NeuroSENSE Monitor can help in assessing the hypnotic effect of anesthetics in adult patients undergoing general anesthesia.

Detailed Description

In particular, the study will focus on the correlation between the WAVcns index, a proprietary quantifier of cortical activity displayed by the NeuroSENSE, with (1) commonly assessed clinical endpoints/variables relating to the DOA, (2) changes in anesthetic drug administration, and (3) the anesthesiologist's assessment of the DOA based on standard of care monitors and his/her own observations of the patient state.

The hypothesis under evaluation is that the WAVcns index is an independent assessor of the progression of the anesthetic state and events of general anesthesia related to hypnotic endpoints.

Conditions

Depth of Anesthesia (DOA)

Study Design

• Observational Model Type: CASE_ONLY
• Study Time Perspective: PROSPECTIVE

Study Groups

Anesthesia

A single study group undergoing general anesthesia procedure to observe post-hoc the effect on the NeuroSENSE monitor readings.

Interventions of interest:

Drug: Propofol induction followed by randomized doses of desflurane; Emergence by stepping down the desflurane ET - See intervention descriptions.

Device: Recording of EEG using NeuroSENSE (blinded to clinicians) - See intervention descriptions.

Other: Data Collection - See intervention descriptions

Propofol induction followed by randomized doses of desflurane

Intervention Type: DRUG

Anesthesia in all patients will be induced with iv propofol 1.5 mg/kg with extra 0.5 mg/kg doses as needed. Anesthesia will be maintained using inhaled desflurane in oxygen/air with the initial desflurane concentration of 1.2 MAC, which will be changed in steps of ±0.4 MAC after reaching the post-intubation steady state. The step changes will be initiated every 7.5 min, as follows: at every level of MAC there is a 1/3 chance in remaining at this level and a 2/3 chance of changing it. The anesthesiologist can accept the change to move to the new level. However, he/she can also reject it to remain at the current level for another 7.5 min. This scheme yields 3 possible desflurane levels: 0.8, 1.2 and 1.6 MAC. The anesthesiologist can also leave the randomization schedule at anytime if clinically indicated, and later re-start it at his/her discretion. All anesthetic doses and their changes fall within conventional dosing.

Recording of EEG using NeuroSENSE

Intervention Type: DEVICE

The NeuroSENSE NS-701 system is a 2-channel device for brain activity monitoring in the operating room, intensive care unit, emergency room and other clinical settings. The system acquires and processes electroencephalograms (EEGs) via noninvasive electrodes placed on a patient's forehead. The acquired raw EEG signals and processed EEG variables are continuously displayed for interpretation by the clinician.

The proprietary processed variable, WAVcns, quantifies the patient's brain activity, which is typically affected by anesthetic drugs. The system displays processed variables based on 2 bilateral channels (1 per brain hemisphere) for use as a supplement to the anesthesia standard of care.

Note: the indications provided by the NeuroSENSE monitor are not used for anesthesia dosing or patient assessment in this study, and the anesthesia provider is blinded to the monitor readings. The device is used only for acquisition of EEG signals and may be used to log the events of interest.

Data collection

Intervention Type: OTHER

Non-invasive blood pressure (BP), heart rate (HR), respiratory rate (RR) and electroencephalogram (EEG) will be recorded during the surgery in all subjects. Also, information about all medically significant events, all study-related events (incl. patient's reactions, responses, observations and assessments) and administered medications (incl. end-tidal (ET) desflurane concentration) will be recorded along with time stamps.

The anesthesia and physiological parameters (e.g., BP, HR, RR, ET agent concentration) outputted from the anesthesia monitor will be recorded electronically during the surgery by the anesthesia monitoring system (data-points will be recorded at least every 3 min for BP and every 10 sec for other variables).

The EEG signal will be continuously recorded by NeuroSENSE NS-701 Monitor (described under a separate intervention).

The CRC will also be present in the Operating Room (OR) to record and manage the recording of all the required information.

Drug: Emergence by stepping down the desflurane ET

Intervention Type: OTHER

Anesthesia will be reduced to facilitate rapid recovery at the discretion of the anesthesiologist, about 20 minutes before the end of surgery. The desflurane ET will be stepped down from 0.8 MAC by steps of 0.2 MAC approximately every 5 min during the Emergence.

Interventions

Propofol induction followed by randomized doses of desflurane

Anesthesia in all patients will be induced with iv propofol 1.5 mg/kg with extra 0.5 mg/kg doses as needed. Anesthesia will be maintained using inhaled desflurane in oxygen/air with the initial desflurane concentration of 1.2 MAC, which will be changed in steps of ±0.4 MAC after reaching the post-intubation steady state. The step changes will be initiated every 7.5 min, as follows: at every level of MAC there is a 1/3 chance in remaining at this level and a 2/3 chance of changing it. The anesthesiologist can accept the change to move to the new level. However, he/she can also reject it to remain at the current level for another 7.5 min. This scheme yields 3 possible desflurane levels: 0.8, 1.2 and 1.6 MAC. The anesthesiologist can also leave the randomization schedule at anytime if clinically indicated, and later re-start it at his/her discretion. All anesthetic doses and their changes fall within conventional dosing.

Intervention Type: DRUG

Recording of EEG using NeuroSENSE

The NeuroSENSE NS-701 system is a 2-channel device for brain activity monitoring in the operating room, intensive care unit, emergency room and other clinical settings. The system acquires and processes electroencephalograms (EEGs) via noninvasive electrodes placed on a patient's forehead. The acquired raw EEG signals and processed EEG variables are continuously displayed for interpretation by the clinician.

The proprietary processed variable, WAVcns, quantifies the patient's brain activity, which is typically affected by anesthetic drugs. The system displays processed variables based on 2 bilateral channels (1 per brain hemisphere) for use as a supplement to the anesthesia standard of care.

Note: the indications provided by the NeuroSENSE monitor are not used for anesthesia dosing or patient assessment in this study, and the anesthesia provider is blinded to the monitor readings. The device is used only for acquisition of EEG signals and may be used to log the events of interest.

Intervention Type: DEVICE

Data collection

Non-invasive blood pressure (BP), heart rate (HR), respiratory rate (RR) and electroencephalogram (EEG) will be recorded during the surgery in all subjects. Also, information about all medically significant events, all study-related events (incl. patient's reactions, responses, observations and assessments) and administered medications (incl. end-tidal (ET) desflurane concentration) will be recorded along with time stamps.

The anesthesia and physiological parameters (e.g., BP, HR, RR, ET agent concentration) outputted from the anesthesia monitor will be recorded electronically during the surgery by the anesthesia monitoring system (data-points will be recorded at least every 3 min for BP and every 10 sec for other variables).

The EEG signal will be continuously recorded by NeuroSENSE NS-701 Monitor (described under a separate intervention).

The CRC will also be present in the Operating Room (OR) to record and manage the recording of all the required information.

Intervention Type: OTHER

Drug: Emergence by stepping down the desflurane ET

Anesthesia will be reduced to facilitate rapid recovery at the discretion of the anesthesiologist, about 20 minutes before the end of surgery. The desflurane ET will be stepped down from 0.8 MAC by steps of 0.2 MAC approximately every 5 min during the Emergence.

Intervention Type: OTHER

Other Intervention Names

Suprane; Diprivan; NeuroSENSE Monitoring System, Model NS-701 (approved in Canada and European market (CE Mark)); NeuroFAST Monitoring System, Model NF-202 (US name, the device is not cleared by the FDA); Suprane

Eligibility Criteria

Inclusion Criteria

• age 18-75 years
• ASA (American Society of Anesthesiologist) physical status I, II, or III
• ability to read and understand the informed consent form
• undergoing anesthesia procedure requiring intubation
• scheduled to undergo either open or laparoscopic abdominal surgical procedures (e.g. colectomy, hysterectomy, radical retropubic prostatectomy, nephrectomy, pancreatectomy, etc.), breast surgery including reduction, reconstruction and mastectomies, or orthopedic surgeries under general anesthesia, expected to last at least 1 hour.

Exclusion Criteria

• history of major head injury (possible abnormal EEG)
• acquired scalp or skull abnormalities (e.g. psoriasis, eczema, angioma, scar tissue, burr holes, cranial implants)
• evidence of recent trauma or active neurological disorder, stroke, seizure disorder, intellectual disability, dementia or diagnosis of Alzheimer's disease
• major antipsychotic medications taken within last 7 days (eg. Lithium, risperidone, olanzapine)
• known history of alcohol or drug abuse within last 30 days
• body mass index (weight in kilograms divided by square of height in meters) > 40.0 kg/m2
• uncontrolled hypertension with blood pressure recorded prior to surgery (systolic blood pressure > 200 mmHg or diastolic blood pressure > 110 mmHg)
• systolic blood pressure < 90 mmHg, recorded prior to surgery
• heart rate (HR) < 45 beats/min, recorded prior to surgery
• insulin-dependent diabetes mellitus
• pregnancy
• any serious medical condition that would interfere with cardiovascular response assessment or study results interpretation

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 75 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

U.S. Army Medical Research Acquisition Activity

FED

Sponsor Role: collaborator

Fraser Health

OTHER

Sponsor Role: collaborator

NeuroWave Systems Inc.

INDUSTRY

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Richard Merchant, MD FRCPC

Role: PRINCIPAL_INVESTIGATOR

Fraser Health

Locations

Fraser Health: Royal Columbian Hospital

New Westminster, British Columbia, Canada

Fraser Health: Eagle Ridge Hospital

Port Moody, British Columbia, Canada

Countries

Canada

References

Gorges M, West NC, Cooke EM, Pi S, Brant RF, Dumont GA, Ansermino JM, Merchant RN. Evaluating NeuroSENSE for assessing depth of hypnosis during desflurane anesthesia: an adaptive, randomized-controlled trial. Can J Anaesth. 2020 Mar;67(3):324-335. doi: 10.1007/s12630-019-01522-5. Epub 2019 Nov 5.

Reference Type: RESULT

PMID: 31691253 (View on PubMed)

Other Identifiers

W81XWH-06-C-0016

Identifier Type: OTHER_GRANT

Identifier Source: secondary_id

925-0701-DCI

Identifier Type: -

Identifier Source: org_study_id