Efficacy of oxycodone in managing visceral pain among women undergoing repeat cesarean section: a randomized controlled trial

Objective: The global cesarean section (CS) rate is on the rise, with ratio of repeat CS becoming more common in China following the two-child policy. Postoperative visceral pain, particularly intense in repeat CS parturients and exacerbated by oxytocin, remains inadequately managed. Oxycodone, acting via κ-opioid receptors, has shown promise in relieving visceral pain, but its efficacy in repeat CS populations is unclear, which was explored in this study. Methods: This randomized controlled trial enrolled 100 parturients undergoing elective repeat CS, randomized to patient-controlled intravenous analgesia (PCIA) with oxycodone (50 mg/100 ml) or sufentanil (100 μg/100 ml). Primary outcomes were maximum visceral pain Numerical Rating Scale (NRS) scores during 0-24 h postoperatively. Secondary outcomes included visceral pain NRS during oxytocin administration on postoperative days 1-2, postoperative inflammatory markers (neutrophil-to-lymphocyte ratio, NLR), time to autonomic activity and PCIA presses. This trial was registered with the Chinese Clinical Trial Registry (ChiCTR2400087624; July 31 2024). Results: < 0.001). Conclusion: In conclusion, oxycodone effectively alleviates postoperative visceral pain and mitigates inflammatory responses in repeat CS parturients, making it a preferred choice for postoperative analgesia in this population.