Clinical Validation of Medasense Pain Response Index (PRI)
Condition: Surgery; Pain
Study type: Interventional

Summary: 
      In our previous study, NCT01631695, we proposed and clinically evaluated the Medasense pain
      response index, PRI, in anesthetized patients undergoing surgery. Note: the name PRI has been
      changed to NoL (Nociception Level) Index.

      The PRI is based on a non-linear combination of several pain-related physiological parameters
      into a one unique index (0-100).

      In this study we aim to validate the performance of the PRI by:

        1. investigating the patient's PRI response to surgical painful stimuli under different
           levels of analgesia:

             -  Investigating patient's PRI response to surgical painful stimuli under two
                different levels of Remifentanil Target Control Infusion (TCI) rates.

             -  Investigating patient's PRI response to standardized painful stimulus (Tetanic
                stimulus) with and without opioids.

        2. investigating the effect of beta-blockers on PRI performance in patients taking chronic
           beta-blocker treatment.

      The study is based on recording and analyzing the subject's physiological signals, while
      recording painful events, medication dosing and different clinical signs.
    

Detailed description: 
      Pain is an unpleasant sensation, ranging from slight discomfort to intense suffering. Since
      pain is a subjective phenomenon, it has frequently defied objective, quantitative
      measurements. Today, in order to measure pain, subjective uni-dimensional scales are used to
      quantify pain. One of the most common scale used to rate a patient's pain intensity is the
      Numeric Pain Scale (NPS), usually scored from 0 to 100. Hitherto, those scales are based on
      the subjective evaluation of pain by the patient.

      During anesthesia the patient cannot communicate and therefore the verbal or other report is
      impossible. As a consequence, due to misrepresentation of the existence or extent of pain,
      care providers may fail to estimate the correct measure of pain and give too much or too
      little medication, leading to possible complications and adverse reactions. A validated
      scoring system of subject's pain level, or as in the case of an anaesthetised patient,
      subject's nociception level, is therefore needed.

      In this study the investigators intend to test and analyze the performances of Medasense pain
      response index, PRI, by comparing it with other standard pain related indicators (Heart Rate
      (HR), Heart Rate Variability (HRV), Skin Conductance, etc) before and after painful stimuli
      at different levels of analgesia. In addition, in order to reduce the variability between
      stimuli, a standardized stimulus (Tetanic ,30 sec, 100Hz, 60mA) will be given to all patients
      after sleep induction and before intubation, with and without administration of Fentanyl and
      the values of the PRI during these stimuli will be investigated.
    

Intervention name(s): Base level of remifentanil effect side concentration: 2ng/ml; Base level of remifentanil effect side concentration: 4ng/ml; chronic beta-blocker treatment
Intervention type(s): Drug; Drug; Other
Intervention description(s): constant remifentanil level of 2ng/ml administered using Target Control Infusion pumps.; constant remifentanil level of 4ng/ml administered using Target Control Infusion pumps.; Patients from the chronic beta-blocker treatment group will not be randomized, and will all be allocated to the high opioid level group.
Other intervention name(s): Ultiva; Ultiva
Intervention MeSH terms: Remifentanil; Adrenergic beta-Antagonists
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary purpose: Screening
Keywords: nociception; analgesia; intraoperative monitoring