The aim of this study is to compare the effectiveness of standard epidural and dural puncture epidural analgesia techniques used under NOL guidance.

The primary aim of this study was to evaluate the effect of NOL-guided antinociception on intraoperative total local anesthetic consumption during anesthesia.

The secondary aim is to compare onset time, analgesia duration time, hemodynamic parameters, time to first postoperative analgesic requirement, and postoperative side effects.

This prospective randomized double-blind study was planned in 36 adult female patients aged 18-75 years, with ASA I-III, who underwent elective open gynecological surgery under general anesthesia with lower midline or Pfannenstiel incision after Ataturk University Medical Faculty Hospital ethics committee approval and written consent of the patients.

Inclusion Criteria:

• ASA I-III physical condition
• patients aged between 18-75 years
• elective surgeries under general anesthesia for gynecological procedures
• lower midline or Pfannenstiel incision

Exclusion Criteria:

• patients with classical contraindications to neuraxial procedures,
• morbidly obese (body mass index > 40 kg / m2),
• pregnant and lactating women
• hypersensitive or allergic to local anesthetic agents,
• abuse of drugs or alcohol in the past 6 months.
• chronic opioid use before surgery,
• using chronic psychoactive drugs in the 90 days before surgery,
• patients with peripheral and central nervous system disease,
• preoperative hemodynamic compromise (patients with irregular sinus heart rhythm and pacemaker)
• patients using antimuscarinic, α2-adrenergic agonists, β1-adrenergic antagonists, antiarrhythmic agents,
• patients with diabetes, severe lung and significant liver disease with increased bilirubin,
• operations that will take less than 2 hours
• MAP >160 mmHg or <60 mmHg, heart rate >90 beats/min or <45 beats/min on the day of surgery
• patients who do not want to participate in the study will be excluded from the study