Retrospective Study of the Safety and Efficacy of Intraoperative Methadone for Pain Management in Patients Undergoing Elective Intracranial Surgery

Abstract

Patients undergoing intracranial surgery experience significant perioperative pain and are typically treated with short-acting opioids. Methadone, with its prolonged half-life and multimodal central nervous system effects, presents a promising option for managing postcraniotomy pain. Despite its proven efficacy in other types of surgeries, the use of methadone in patients undergoing craniotomy has not yet been explored. A retrospective chart review was conducted for 60 adult patients ranging in age from 18 to 81 years who received methadone during intracranial surgeries. The primary outcome of interest was the total opioid consumption in oral morphine milligram equivalents (MMEs) and patient-reported pain scores within 24 hours and up to 72 hours postoperatively. The methadone dosage varied from 5 to 20 mg. In the infratentorial group, the median total MME on postoperative day 1, 2, and 3 was 30.5, 17, and 0.8, respectively, with mean pain scores of 3.56, 3.91, and 2.71. In the supratentorial group, the median total MME on postoperative day 1, 2, and 3 was 17.85, 15.4, and 1.2, with mean pain scores of 2.31, 1.68, and 2.21, respectively. Patients who were chronic opioid users had significantly higher pain scores and average opioid use (P < 0.05). None of the patients required administration of naloxone or airway interventions. Comparison with the historical control showed that our study patients had lower pain scores and MME. The single intraoperative dose of methadone is well tolerated by adult patients undergoing various types of intracranial surgeries, with minimal side effects, including elderly patients aged 65 years or older.