Pain Monitor During Anesthesia Clinical Trial
Official title:
Evaluation of the Last Version of the PMD200TM and Its NoL Index in Patients Undergoing Laparotomies With Intraoperative Epidural Analgesia
Title: Evaluation of the last version of the PMD200TM and its NoL index in patients
undergoing laparotomies with intraoperative epidural analgesia Objectives: Measure NoL Index
changes after a standardized nociceptive electrical stimulus at various intravenous
remifentanil infusion rates (0.005, 0.05, 0.1 mcg/kg/min) and also after clinical stimuli
such as intubation.
Study Design: Prospective observational study Subject Population: Adults scheduled to undergo
elective abdominal surgery with laparotomy under general anesthesia and epidural analgesia
Sample Size: 30 patients Study Duration: Starts April 2016 - Ends November 2016 Study Center:
Maisonneuve-Rosemont Hospital, Montreal, Quebec, Canada Adverse Events: None expected
The motivation behind the actual observational proposed study is to validate the ability of
the new PMD-200TM system to accurately detect a nociceptive stimulus that occur during
anesthesia (e.g. laryngoscopy for tracheal intubation, standardized electrical stimulations).
The NoL index will also be recorded during period of time without any stimulation and called
baseline values of NoL under standard anesthesia.
The PMD100TM was an early prototype of the pain monitor device developed by Medasense
Biometrics Ltd (Ramat Yishai, Israel), which was used in our center in Montreal in a recently
completed clinical trial. This device is based on a software that was integrated into a
computer to analyze the different criteria with a multi-parametric index named NoL which
estimates the nociception level during general anesthesia and incorporates heart rate, heart
rate variability (0.15-0.4 Hz band power), plethysmograph wave amplitude, skin conductance
level, number of skin conductance fluctuations (NSCF), and their time derivatives, using a
non-linear regression technique. The rationale for the use of skin conductance and NSCF is
that the presence of a physical stressor leads to a sympathetic-mediated filling of the
palmar sweat glands, thus changing the ion concentration and the skin conductance. It has
been shown to correlate with clinical stress score during intubation and to be less reactive
to a tetanic stimulation when remifentanil was perfused. With the Medasense device PMD100TM,
these five variables are obtained through a single non-invasive finger probe connecting the
finger of the patient to the computer. Only signals from the patient are recorded. No signal
is sent to the patient by the PMD100TM. The NoL Index obtained and displayed on the Medasense
PMD200™ device is a single number from 0 to 100, with a lower score proposed to represent
less painful stimulation.
The PMD-200TM system is an advanced configuration product in the final stages of development,
with the introduction of several enhancements related to the Hardware (HW) and the Software
(SW) platform:
1. Enhanced finger probe - which include 4 new sensors (slightly different from the sensors
used in PMD-100 and more efficient in terms of quality of signals)
2. Improvement in the signal acquisition board - a HW module which converts the analog
signals from all sensors to digital data
3. All in one system - enables integrated viewing of the recorded signals and NoL index
through a touch based user interface (the previous interface for the PMD100 was on a
computer screen)
4. A new Graphic user interface for the user The purpose of this new prospective
observational study with the finalized PMD200TM device is to evaluate the responses of a
multi-parameter index (the Nociception Level [NoL] Index) when patients under combined
general anesthesia/epidural anesthesia for laparotomies are subjected to standard
painful stimuli (laryngoscopy for intubation). Also during surgery, standardized
electrical stimulations over the ulnar nerve (70 mA, 100 Hz for 30 seconds) at different
doses of remifentanil steady state infusion (0.005 mcg/kg/min; 0.05 mcg/kg/min; 0.1
mcg/kg/min) will be performed as we did in our previous study at HMR after Scientific
and Ethic Committee approval in 2015.
Studying the effect of different doses of infused remifentanil on the new and finalized
version of the NoL Index from the PMD200TM device in patients subjected to a standardized
painful stimulus under general anaesthesia would help validating this final version and to
compare results to the prototype used in our center in a previous study.
Primary Aim: Establish a correlation between the NoL Index changes and the infused dose of
remifentanil at the time the stimulation was applied. It is expected to see a strong
correlation meaning that when the remifentanil infusion is high, the NoL response to the
standardized electrical stimulation might be low.
Secondary Aims: NoL changes at different times of the surgery. Heart rate and blood Pressure
and BISpectral index changes after clinical stimulus such as intubation, incision, and
standardized electrical stimulations at different concentrations/infusions of remifentanil
(0.005, 0.05, 0.1 msg/kg/min). Measure the sensitivity and specificity of the study criteria
(NoL, BIS, Heart Rate and Mean Blood Pressure) in detecting a painful stimulus such as
intubation and electrical stimulus at remifentanil 0.005mcg/kg/min if infusion.
Also, at the end of the surgery, we will still record the NoL index from the PMD200TM device.
And we will also record the first pain score when the patient is extubated in PACU. This will
be done in an observational manner. We will evaluate whether the last NoL index recorded
under general anesthesia at the end of the surgical procedure (last stiches) with patient
still under controlled ventilation does correlate with the first pain scores in PACU.
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