Nociception Monitoring

The aim of this study is to observe the effect of administering local anesthetic to the abdominal wall at the beginning or end of surgery under general anesthesia on opioid consumption during surgery. The hypothesis of this study is to demonstrate that administering a rectus sheath block before the surgical procedure under general anesthesia is effective in reducing intraoperative opioid consumption and opioid-related side effects compared to administering it after the surgery is completed.

This observational study aims to compare two nociception monitoring methods. The Nociception Level (NOL) index and the Surgical Pleth Index (SPI) in the pediatric population during general anesthesia. While both monitors are designed to assess nociceptive responses through autonomic nervous system activity, they differ in methodology and parameters measured. The NOL index integrates multiple physiological signals using a self-learning algorithm, while SPI focuses on heart rate variability and plethysmographic amplitude. Although both have been studied individually in children, a direct comparison has not yet been conducted. This study will evaluate and compare each monitor's ability to detect and quantify nociceptive stimuli (surgical and tetanic) in children. The investigators hypothesize that the NOL monitor and SPI monitor will both be able to quantify surgical stimuli and tetanic stimuli with monitors response to surgical stimuli \> monitors response to tetanic stimuli. However, the investigators also hypothesize that the NOL index will do this superiorly, as it utilizes a self-learning algorithm and more parameters are incorporated in its algorithm