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

BACKGROUND: Management of acute postoperative pain is one of the major challenges in pediatric patients. Oral oxycodone has shown good pain relief in postoperative pain relief in children, but no studies have investigated intravenous oxycodone in this context. OBJECTIVE: whether oxycodone PCIA can provide adequate and safe postoperative pain relief, in comparison to tramadol as reference opioid drug. DESIGN: a randomized, double-blind, parallel, multi-center clinical trial. SETTING: five university medical centers and three teaching hospitals in China. PARTICIPANTS: patients aged 3-month-old to 6-year-old undergoing elective surgery under general anesthesia. INTERVENTION: patients were randomly allocated to either tramadol (n = 109) or oxycodone (n = 89) as main postoperative opioid analgesic. Tramadol or oxycodone were administered with a loading dose at the end of surgery (1 or 0.1 mg.kg(–1), respectively), then with a parent-controlled intravenous device with fixed bolus doses only (0.5 or 0.05 mg.kg–1, respectively), and a 10-min lockout time. OUTCOMES: the primary outcome was adequate postoperative pain relief, defined as a face, legs, activity, cry, and consolability (FLACC) score < 4/10 in the post-anesthesia care unit (PACU), with no need for an alternative rescue analgesia. FLACC was measured 10 min after extubation then every 10 min until discharge from PACU. Analgesia was currently conducted with the boluses of either tramadol or oxycodone if FLACC was ≥ 3, up to three bolus doses, after what rescue alternative analgesia was administered. RESULTS: tramadol and oxycodone provided a similar level of adequate postoperative pain relief in PACU and in the wards. No significant differences were either noted for the raw FLACC scores, the bolus dose demand in PACU, the time between the first bolus dose and discharge from PACU, analgesic drug consumption, bolus times required in the wards, function activity score, or the parents’ satisfaction. The main observed side effects in both groups were nausea and vomiting, with no difference between groups. However, patients in the oxycodone group showed less sedation levels and had a shorter stay in the PACU, compared with the tramadol group. CONCLUSIONS: an adequate postoperative analgesia can be achieved with intravenous oxycodone, this with less side effects than tramadol. It can therefore be a choice for postoperative pain relief in pediatric patients. TRIAL REGISTRATION: The study was registered at www.chictr.org.cn (Registration number: ChiCTR1800016372; date of first registration: 28/05/2018; updated date:06/01/2023).