Analysis of the Effects of Epidural Anesthesia on the Nociception Level Index (NOL) during Abdominal Surgery.

: The NOL system (PMD-200™ Nociception Level Monitor; Medasense Ltd., Ramat Gan, Israel) is used for the real-time detection of physiological nociception in anesthetized patients by assessing the parameters indicative of sympathetic activity, such as photoplethysmography, skin conductance, peripheral temperature, and accelerometry, which are quantified into the NOL-Index. This index is more sensitive than traditional clinical parameters in estimating pain and stress responses.