Performance Assessment of the PMD-200 Under General Anesthesia

The primary efficacy objective of this study is to demonstrate that the NOL Index of the
PMD-200 monitor (Medasense Biometrics Ltd., Ramat Gan, Israel) is correlated with the
responses to noxious stimuli and analgesic administration during the surgical procedure
(prior and following a stimuli or titration), and the secondary efficacy objective of the
study is to determine whether the NOL values can be correlated to other nociception
predictors (e.g., increase in heart rate or blood pressure) following a noxious stimuli. The
primary safety objective of this study is to assess the rate of any adverse reaction related
to the study device. This device will not be used to make any clinical decision.

General anesthesia is the combination of various components including lack of movement,
hypnosis, amnesia, control of autonomic responses, and attenuation of the response to noxious
stimulation. Some anesthetic components, such as muscle relaxation and absence of movement
are easy to assess with a twitch monitor. Similarly, hypnotic state can be estimated using
processed electroencephalographic signals, but the anesthetic component that remains the most
challenging to assess is the nociceptive/antinociceptive state. Typically, intraoperative
nociception is estimated from autonomic responses (such as change in blood pressure and heart
rate) and clinical signs such as tearing and sweating, but these variables can be very
unreliable in predicting pain such as in patients who take beta blockers for treatment of
high blood pressure whose heart rate may not increase in response to pain, patients with
significant bleeding during surgery whose blood pressure may not increase in response to
pain, etc. Effective antinociception is an important component of balanced anesthesia and
appears to enhance postoperative outcomes. The most obvious potential consequence of
insufficient intraoperative antinociceptive treatment is excessive postoperative pain, but
inadequate treatment may also promote inflammatory, hormonal, and immunologic imbalances.

A novel measure of nociception is the nociception level (NoL) index. The NoL index ranges
from 0 to 100 and is based on a nonlinear combination of nociception-related physiologic
variables, specifically heart rate (HR), heart rate variability at the 0.15- to 0.4-Hz band
power, photoplethysmograph wave amplitude (PPGA), skin conductance level, number of skin
conductance fluctuations, and their time derivatives. The NoL index estimates the
nociceptive/antinociceptive state from these components measures using random forest
regression. Previous experimental work on a small number of patients showed that the NoL
index is superior to each individual component and to a linear combination of the components.
However, it remains unknown whether the NoL index accurately quantifies patients'
intraoperative responses to noxious stimuli of varying intensities. The investigators
therefore wish to evaluate the ability of the NoL index to discriminate noxious from
nonnoxious stimuli, respond to analgesic administration, and progressively increase in
response to increasing intensity of noxious stimulation.

In this observational study, The investigators attempt to learn the proper use of the PMD-200
and assess safety and efficacy of this device as mentioned above; however, no clinical
decision will be based on the NoL index obtained.

Inclusion Criteria:

- Age > 18 years old.

- Requiring laparoscopic gastrointestinal or laparoscopic hysterectomy under general
anesthesia (without regional anesthesia)

- Patient provides informed consent

Exclusion Criteria:

- History of severe cardiac arrhythmias within the last 12 months

- Chronic pain conditions or analgesic usage (>1 month of large doses of opioids: more
than 30mg oral equivalent of morphine)