Comparative Study between Nalbuphine versus Tramadol on Postoperative Analgesia for Abdominal Surgery in Pediatric Cancer Patients: A Prospective, Randomized Clinical Trial

Background Effective postoperative pain management in pediatric patients is essential for recovery, though no single analgesic is considered superior. Nalbuphine and tramadol are common alternatives to traditional opioids, each with a distinct pharmacological profile. This study compares the efficacy and safety of nalbuphine versus tramadol in managing postoperative pain after abdominal surgery in pediatric cancer patients. Methods This prospective, randomized clinical trial involved 128 children with cancers (3–12 years) undergoing elective abdominal surgery. Patients were randomized into two groups: the Nalbuphine group (0.2 mg/kg IV every 8 hours) and the Tramadol group (2 mg/kg IV every 8 hours) for 72 hours postoperatively. Pain was assessed using the Wong-Baker FACES Pain Scale (WB), and rescue analgesia with paracetamol was provided as needed. The primary outcome measure was the time to first rescue analgesia, while secondary outcomes included pain scores, paracetamol consumption, and adverse effects. Results Nalbuphine provided superior pain relief during the first 24 hours postoperatively, with significantly lower WB scores compared to tramadol. However, tramadol demonstrated complete pain resolution by 48–72 hours, while some nalbuphine patients reported mild pain. The need for rescue analgesia was low and comparable between groups (9.4% vs. 7.8%, p = 0.752). Both drugs maintained hemodynamic stability and had similar safety profiles, with minimal adverse effects. Conclusion Nalbuphine offers better early postoperative pain control, while tramadol provides more sustained analgesia beyond 24 hours. Both drugs are effective and safe. Trial registration: this study was retrospectively registered at clinical trial gov. (ID: NCT07110051), URL: https://clinicaltrials.gov/study/NCT07110051?cond=NCT07110051&rank=1, Date: 31/07/2025.