The Effect of Nociception Level (NOL) Monitoring on Intraoperative Opioid Consumption in Hip Surgeries

Hip surgeries are one of the most painful surgical operations, and inadequate pain management increases postoperative morbidity and mortality.The incidence of chronic pain after hip surgery is quite high, at 11-40%.For this reason, hip surgeries are complex and specialized surgeries in terms of pain management.According to the surgical procedures pioneered by the European Society of Regional Anesthesia, Pericapsular nerve block (PENG) block is among the recommendations with a high level of evidence for hip surgery in the multimodal analgesia steps guide.In the literature, there are studies comparing the postoperative analgesic effectiveness of PENG block in hip surgeries, but the results are contradictory.In addition, intraoperative pain monitoring was not used in these studies, instead intraoperative analgesia management was provided according to hemodynamic parameters, which may not be objective.Opioid infusion is used in analgesia management during the intraoperative period.While not providing effective analgesia due to insufficient opioid use will have effects, excessive opioid use also has many side effects.Therefore, it would not be correct to administer the same dose of opioid infusion to every patient. As seen in the data in the literature and in daily practice, hemodynamic parameters (such as heart rate, blood pressure) are used for pain monitoring of the patient under general anesthesia, and these parameters may change depending on many other factors.Although some devices that aim to provide pain monitoring by evaluating the effects of pain on the sympathetic system are available on the market, their usage areas have remained limited since their reliability has not been fully demonstrated. Nociception level index (NoL) monitoring provides effective monitoring as it evaluates each patient separately using different parameters (heart rate, heart rate variability, photo-plethysmographic waveform amplitude, skin conductance level, number of skin conductance fluctuations and their time derivatives).While planning this study, İnvestigators aimed to use NoL monitoring in hip surgery, where postoperative pain management is quite challenging and important, as it provides objective and personalized pain management in patients under general anesthesia.When other studies in the literature are examined, the effects of regional techniques have been compared only in the postoperative period.Its effects in the intraoperative period have not been evaluated on a patient basis, and the opioid infusion rate has been adjusted with hemodynamic findings, which are affected by many parameters such as bleeding and drug use.In this study, İnvestigators aim to compare the effects of intraoperative pain monitoring and personalized analgesia treatment and the regional technique both in the intraoperative period and in the postoperative period.