Propofol + Remifentanil vs. Propofol + Dexmedetomidine in Adolescent Idiopathic Scoliosis Patients Having Spine Surgery

Patients with Adolescent Idiopathic Scoliosis (AIS) may need surgery to correct their scoliosis. General anesthesia is required for this surgery, and a multimodal analgesic regimen using combinations of opioid and non-opioid medications is the standard of care. Total intravenous anesthesia (TIVA) is the usual anesthetic technique of choice. The purpose of this study is to compare two combinations of TIVA medications in children AIS having posterior spinal fusion surgery. The most common TIVA for this surgery at our institution is Propofol + Remifentanil. Remifentanil is a popular choice because of its rapid onset, extremely short context-sensitive half-life, potency, and its rapid recovery from drug effect. However, an important concern with intraoperative remifentanil infusion is the possible development of acute opioid-induced hyperalgesia (OIH). In adults, OIH is a well-documented feature linked to intraoperative remifentanil administration, manifesting as increased postoperative analgesic requirement and paradoxical increase in sensitivity to painful stimuli. In pediatric patients, the phenomenon is not as well characterized. An alternative TIVA that is very commonly used for adult spine surgery is propofol + dexmedetomidine (DEX). DEX is a highly selective alpha2-adrenergic receptor agonist with sedative, analgesic, and sympatholytic properties. Despite the lack of FDA approval for pediatric use, DEX is widely used off-label in pediatric patients in the US and worldwide and has previously been shown to be safe and efficacious for various clinical indications including procedural sedation, craniotomy-awake-surgery, cardiac surgery, and posterior spinal fusion for scoliosis. DEX is currently used safely in pediatric and adult spine patients in our institution. The most common adverse effect is intraoperative bradycardia. Participants will be randomized to receive one of the two TIVAs to see if one or the other results in lower opioid consumption, and lower Visual Analog Scale (VAS) pain scores in the post-operative period (POD# 0 and 1). The investigators hypothesize that the use of DEX will avoid OIH and this will lead to less opioid consumption in the postoperative period, and superior postoperative pain control. The investigators also hope to show that the use of DEX will not significantly prolong time to moving feet to command and extubation at conclusion of surgery.