This study will investigate whether a combination of three anesthetic medications will reduce intraoperative and postoperative pain in patients undergoing complex spine surgery, and whether it will reduce the use of opioid pain medication after surgery.

Dexmedetomidine, methadone and ketamine offer benefits when used as adjuncts in complex spine surgeries. Dexmedetomidine is reported to attenuate intraoperative stress responses without interfering with neuromonitoring while potentially improving postoperative pain control and reducing opioid consumption in complex spine surgery. Methadone use intraoperatively improves postoperative pain control and reduced opioid requirements following complex spine surgery. Consensus guidelines from the American Society of Regional Anesthesia and Pain Medicine, the American Academy of Pain Medicine, and the American Society of Anesthesiologists support the use of ketamine in acute pain management in surgeries like spine surgery. Perioperative ketamine use in spine surgery results in lower pain scores and reduced opioid utilization postoperatively. The use of dexmedetomidine, methadone and ketamine as adjuncts may improve postoperative pain control while reducing opioid requirements, lowering stress responses, and without significantly impacting neuromonitoring in complex spine surgery or increasing drug related adverse events.

Inclusion criteria:

• Age 18-79 years of age
• Patients undergoing complex spine surgery, defined as 3 or more levels
• English-speaking
• Able to consent for themselves

Exclusion criteria:

• Patients who are unable to consent to study participation in English
• Patients who are unable to consent for themselves.
• Patients with prolonged QT syndrome
• Pregnancy

Additional screening measures:

• Preoperative ECG will be performed in preoperative holding as part of standard of care to assess for prolonged QTc prior to administration of methadone as part of SOC.
• Pregnancy test will be performed as part of SOC on the day of surgery.