Oxycodone vs. tramadol in postoperative parent-controlled intravenous analgesia in children: a prospective, randomized, double-blinded, multiple-center clinical trial

Background: Acute postoperative pain management in pediatric patients is one of the major challenges for anesthesiologist. Oxycodone has shown superior effects in both postoperative somatic and visceral pain relief in adult patients after surgery. However, limited studies have investigated the administration of oxycodone for pain relief in children after surgery. We therefore test the hypothesis that oxycodone can provide adequate postoperative pain relief in children with parent-controlled intravenous analgesia (PCIA). The secondary outcomes included the incidence of major adverse complications and parents’ satisfaction.Methods: This is a prospective, randomized, double-blinded, multiple-center clinical trial. Children patients undergoing elective surgery under general anesthesia were randomly allocated to the tramadol & oxycodone groups. Tramadol (1.0mg/kg) or oxycodone (0.1mg/kg) was administrated at the end of surgery, followed by PCIA without background infusion. A fixed bolus dose of 0.5mg/kg and 0.05mg/kg was set to tramadol and oxycodone-PCIA, respectively. The lockout time of 10 mins was set to all patients. Results: Both tramadol and oxycodone-PCIA provided well postoperative pain control (FLACC<4) in post anesthesia care unit (PACU) and in the wards, and no alterative rescue analgesia requirement was needed. There was no difference in the FLACC scores and bolus does demand in the PACU, length between the first bolus dose and the discharge from PACU, analgesic drug consumption, bolus times, function activity score or parents’ satisfaction scores between tramadol and oxycodone group in the wards (P>0.05). The major adverse effects in both groups were nausea & vomiting, but there was no difference in the incidence either in the PACU or in the wards (p>0.05). Patients in oxycodone groups showed milder sedation levels and a shorter stay in the PACU when compared with the tramadol group (P<005). Conclusions：Oxycodone can provide an adequate postoperative analgesia in children, with mild side effects. Oxycodone can be an alternative choice for postoperative pain relief for children patients.Trial registration: The study was registered at www.chictr.org.cn (Registration number: ChiCTR1800016372; Date of first registration: 28/05/2018).