Methadone in Ambulatory Surgery

Not Applicable

Completed

Interventions: Drug: methadone
Drug: Control (Intra-operative administration of opioids, other than methadone)

Brief Summary: The μ-opioid receptor agonist methadone is frequently used in adult anesthesia and adult pain therapy. Methadone has an extremely long half-life, which confers therapeutic advantage by providing more stable plasma concentrations and long-lasting pain relief. Methadone perioperative pharmacokinetics and effectiveness in perioperative pain relief in inpatients is well characterized. There is, however, no information on methadone use in an ambulatory surgery setting and outpatient procedures. This pilot investigation will determine effectiveness of intraoperative methadone in reducing postoperative opioid consumption and providing improved pain relief in patients undergoing moderately painful, ambulatory surgical procedures.

Recruitment & Eligibility

Inclusion Criteria

Age 18-65 years
Undergoing general anesthesia and moderately painful, ambulatory surgical procedures with anticipated overnight, postop hospital stay of < 24 hours
Signed, written, informed consent

Exclusion Criteria

History of or known liver or kidney disease.
Females who are pregnant or nursing.
Opioid tolerant patients (e.g. preoperative methadone therapy or use of fentanyl transdermal patches)
History of allergy to methadone

Arm && Interventions

Group	Intervention	Description
Treatment methadone 0.15 mg/kg	methadone	-
Control	Control (Intra-operative administration of opioids, other than methadone)	Control (Intra-operative administration of opioids, other than methadone)
Treatment methadone 0.1 mg/kg	methadone	methadone 0.1 mg/kg

Primary Outcome Measures

Name	Time	Method
Intraoperative Opioid Administration	Administered at induction of anesthesia	Data on opioids administered intraoperatively will be collected from the subject's EMR.
Postoperative Opioid Administration	EMR reviewed at 24 hours post-administration or at hospital discharge	Data on opioids administered postoperatively will be collected from the subject's EMR. Pain severity will be assessed using Numeric Rating Scale and colored-visual analogue scale. Pain relief postoperatively will be assessed using a 5 point scale \[0-no relief, 4-complete relief\]

Secondary Outcome Measures

Name	Time	Method
Opioid Consumption Within First 30 Postoperative Days	30 days	Daily opioid consumption for approx 30 days following surgery (from hospital discharge until postop clinic visit).
Pain Relief Within First 30 Postoperative Days	30 days	Daily pain self-assessments using a numeric (0-10) rating scale were recorded in a home diary for approx 30 days following surgery (from hospital discharge until postop clinic visit). Zero was no pain and 10 was the worst possible pain. Patient's 30-day post-discharge scores were averaged individually and compared in between groups. In addition, participants recorded pain interference with 7 activities of daily living - mood, ability to walk or move, sleep, normal work outside the home, normal work at home, recreational activities, and enjoyment of life on a 5-point Likert scale. Questions were based on the Patient-Reported Outcomes Measurement Information System Pain Behavior and Pain Interference item banks. Patients also recorded opioid and nonopioid analgesic use, sedation, and time to return to work.