• Journal: Anesthesiology

• PMID: 37350677

• Type of study: Randomized, dose-finding, feasibility study

• Objective

  • To determine an optimally analgesic and well-tolerated dose of methadone for patients undergoing next-day discharge surgery

• Methods

  • Almost 7500 subjects

    • International

    • Multicenter

  • Inclusion criteria

    • 18-65 years of age

    • Elective surgery with a planned next-day discharge requiring general anesthesia

      • Primarily women undergoing hysterectomies

  • Outcomes

    • Perioperative opioid usage

    • Post-op pain scores

    • Post-op adverse events

    • Post-discharge opioid usage

  • Methadone dose groups

    • 0.1 mg/kg IBW

    • 0.2 mg/kg IBW

    • 0.25 mg/kg IBW

    • 0.3 mg/kg IBW

• Results

  • Perioperative opioid usage

    • Total perioperative opioid use was reduced in all methadone groups

  • Post-op pain scores

    • Pain scores were reduced in the methadone groups

  • Post-op adverse events

    • No clinically meaningful differences between methadone groups and control

  • Post-discharge opioid usage

    • Trend toward reduced usage in the 0.2, 0.25, and 0.3 mg/kg IBW groups

• Strengths

  • Prospective, randomized controlled trial

  • Blinded except for anesthesia providers

  • Good protocol

  • Multiple dose groups show dose-response

  • Multiple outcomes used to assess pain control and opioid use

• Weaknesses

  • Limited generalizability

    • Excluded opioid-tolerant patients

    • Predominantly female, laparoscopic hysterectomy, ASA 2

  • Small sample size (pilot study)

  • Limited statistical analysis

• Key Point: A dose of 0.25mg/kg was the optimal amount of methadone in patients undergoing next-day discharge surgeries (primarily hysterectomies)

Anesthesiology. 2023 Oct 1;139(4):405-419