Effectiveness of the NeuroSENSE for Monitoring the Hypnotic Depth of Anesthesia
Condition: Depth of Anesthesia (DOA)
Study type: Observational

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.
    

Intervention name(s): Propofol induction followed by randomized doses of desflurane; Recording of EEG using NeuroSENSE; Data collection; Drug: Emergence by stepping down the desflurane ET
Intervention type(s): Drug; Device; Other; Other
Intervention description(s): 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.; 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.; 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.; 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.
Other intervention name(s): 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
Intervention MeSH terms: Propofol; Desflurane
Observational model: Case-Only
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Adult patients undergoing general anesthesia procedure in the context of 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.
      
Keywords: NeuroSENSE; Anesthesia; Hypnosis; Desflurane; Propofol