A Randomized, Double-Blind, Placebo-Controlled Trial of Anrikefon for Postoperative Analgesia After Percutaneous Nephrolithotomy

This study evaluates whether a single dose of anrikefon, given intravenously shortly before the end of kidney stone removal surgery (PCNL), can reduce opioid-related side effects such as nausea, vomiting, itching, oversedation, and breathing problems in the first 24 hours after surgery. All participants receive the same standard pain control regimen (flurbiprofen axetil plus a sufentanil patient-controlled pump). In addition, half receive anrikefon and half receive a placebo (saline), decided by random allocation, with neither patients nor doctors knowing who receives which. A total of 160 adults (18-75 years) undergoing elective PCNL at Beijing Tsinghua Changgung Hospital will take part. Pain scores, opioid use, recovery, satisfaction, kidney function and side effects will be followed for up to 3 days after surgery.

Inclusion Criteria: * Age 18-75 years, either sex * Scheduled elective unilateral percutaneous nephrolithotomy (PCNL) under general anesthesia (stone diameter \>2 cm, meeting PCNL indications) * ASA classification I-III * Body mass index (BMI) 18-35 kg/m2 * Preoperative estimated glomerular filtration rate (eGFR) \>=60 mL/min/1.73 m2 * Resting pain NRS score \