Perioperative methadone for posterior spinal fusion in adolescents: Results from a double‐blind randomized‐controlled trial

Background Posterior spinal fusion is the most common surgical procedure performed for correction of adolescent idiopathic scoliosis in the United States. Intraoperative methadone has been shown to improve pain control in adult patients undergoing complex spine surgery, and current pediatric studies show encouraging results; however, prospective randomized‐controlled trials are lacking in the pediatric literature. Aims We conducted a single‐center double‐blind randomized‐controlled trial to compare intraoperative use of methadone to morphine in pediatric patients undergoing posterior spinal fusion. Methods A total of 47 adolescents undergoing posterior spinal fusion were randomized (stratified by sex) to either a methadone (n = 25) or morphine (n = 22) group. The primary outcome was postoperative opioid consumption. Secondary outcomes included postoperative pain severity, opioid‐related side effects, and ratio of patient‐controlled analgesia injections: attempts as a behavioral index of uncontrolled pain. Results Patients in the methadone group consumed less total opioid postoperatively (median [interquartile range], 0.3 mg/kg [0.1, 0.5]) than patients in the morphine group (0.3 mg/kg [0.2, 0.6]), median difference [95% confidence interval] −0.07 [−0.2 to 0.02]; (p = .026). Despite the lower amount of opioid used postoperatively, pain scores for the methadone group (3.5 [3.0, 4.3]) were not significantly different from those in the morphine group (4.0 [3.2, 5.0]; p = .250). Groups did not differ on opioid‐related side effects. Conclusions A two‐dose intraoperative methadone regimen resulted in decreased opioid consumption compared to morphine. Although the clinical significance of these results may be limited, the analgesic equipoise without increased opioid‐related side effects and potential for a lower incidence of chronic pain may tip the balance in favor of routine methadone use for adolescents undergoing posterior spinal fusion.