Analgesic effects of methadone and magnesium following posterior spinal fusion for idiopathic scoliosis in adolescents: a randomized controlled trial
To provide optimal conditions for neurophysiological monitoring and rapid awakening, remifentanil is commonly used during pediatric spinal surgery. However, remifentanil may induce hyperalgesia and increase postoperative opioid requirements. We evaluated the potential of methadone or magnesium to prevent remifentanil-induced hyperalgesia.
Using a prospective, randomized, blinded design, adolescents presenting for posterior spinal fusion to treat idiopathic scoliosis were assigned to receive desflurane with remifentanil alone (REMI), remifentanil + methadone (MET) (0.1 mg/kg IV over 15 min), or remifentanil + magnesium (MAG) (50 mg/kg bolus over 30 min followed by 10 mg/kg/h). Primary outcomes were opioid requirements and postoperative pain scores. Secondary outcomes included intraoperative anesthetic requirements, neurophysiological monitoring conditions, and emergence times.
Data analysis included 60 patients. Total opioid requirement (hydromorphone) in the REMI group (received perioperatively and on the inpatient ward) was 0.34 ± 0.11 mg/kg compared to 0.26 ± 0.10 mg/kg in the MET group (95% confidence interval (CI) of difference: − 0.14, − 0.01; p = 0.035). The difference in opioid requirements between the REMI and MET group was related to intraoperative dosing (0.04 ± 0.02 mg/kg vs. 0.02 ± 0.01 mg/kg; 95% CI of difference: − 0.01, − 0.02; p = 0.003). No difference was noted in pain scores, and no differences were noted when comparing the REMI and MAG groups.
With the dosing regimens in the current study, the only benefit noted with methadone was a decrease in perioperative opioid requirements. However, given the potential for hyperalgesia with the intraoperative use of remifentanil, adjunctive use of methadone appears warranted.
KeywordsPosterior spinal fusion Magnesium Methadone
This project was supported by The Clinical and Translational Intramural Funding Program through the Research Institute at Nationwide Children’s Hospital (Columbus, Ohio).
Compliance with ethical standards
Conflict of interest
The authors have no other funding or conflict of interest to report.
The study was approved by the Institutional Review Board at Nationwide Children’s Hospital (IRB13-00036) and registered at ClinicalTrails.gov (NCT01795495). An investigational new drug (IND) application for this study was approved by The Food and Drug Administration (FDA) prior to study initiation (IND117889).
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