Nociception Level Index Monitoring During Cesarean Section

Postoperative pain following cesarean section remains an important clinical concern because inadequate analgesia may delay maternal recovery, increase opioid consumption, and negatively affect early breastfeeding and maternal-infant bonding. Conventional intraoperative monitoring does not directly assess nociceptive responses, making individualized analgesic administration challenging.

The Nociception Level (NOL) index is a multiparametric monitoring system that integrates photoplethysmography, galvanic skin response, peripheral temperature, and accelerometer signals to provide an objective assessment of nociception during anesthesia. This technology may enable more individualized opioid administration based on the patient's nociceptive response.

In this prospective randomized controlled trial, patients undergoing elective cesarean section under general anesthesia were randomized to receive either NOL-guided intraoperative analgesia or standard intraoperative monitoring. In the intervention group, fentanyl administration after fetal delivery was guided by the NOL index, whereas patients in the control group received conventional hemodynamic-guided analgesia.

Postoperative pain was evaluated using the visual analog scale (VAS) at predefined time points during the first 24 postoperative hours. Rescue opioid requirements, total postoperative analgesic consumption, and time to first breastfeeding were also recorded. The study was designed to determine whether NOL-guided analgesia could improve early postoperative pain control and reduce postoperative opioid requirements compared with conventional monitoring.

Inclusion criteria

• Female patients undergoing elective cesarean section under general anesthesia.
• Ability to provide written informed consent.

Exclusion criteria

• Refusal to participate.
• Emergency cesarean section.
• High-risk pregnancy (including hypertensive disorders of pregnancy, diabetes mellitus, preterm labor, or fetal growth restriction).
• Placental abnormalities.
• History of allergy to any study medication.
• History of malignant hyperthermia.
• Alcohol or substance abuse.
• Severe cardiac disease or severe arrhythmia.
• Peripheral vascular disease.
• Renal or hepatic failure.
• Contraindication to corticosteroid administration.