Does Intraoperative Methadone Prevent Postoperative Pain in Bariatric Surgery?

January 25, 2017 updated by: Felipe Chiodini Machado, University of Sao Paulo General Hospital
The recent increase in obesity has led to an increase in the need for bariatric surgery. In this group of patients the postoperative pain management is of vital importance. One strategy to improve postoperative analgesia is the use of intraoperative methadone, specially in those patients which regional anesthesia is not feasible. There is evidence that the use of intraoperative methadone can lead to a analgesia lasting 24 to 36 hours, while not associated with increased side effects when compared to other opioids with short or intermediate duration of action. In this study the investigators will evaluate the efficacy of intraoperative methadone in reducing postoperative pain and opioid consumption.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Despite recent developments in postoperative pain control, many patients still suffer from moderate to severe pain after surgery. It is estimated that postoperative severe pain occurs in 20 to 40% of surgical procedures. With the recent increase in obesity incidence in the last years, the need for bariatric surgical intervention is greater. The management of postoperative pain in obese patients is particularly important, since this population have increased susceptibility to cardiovascular, pulmonary and thromboembolic perioperatively.

One of the strategies to improve pain management in the perioperative period is the intraoperative use of intravenous methadone, given its pharmacokinetic profile, specially in those patients in which regional anesthesia is contraindicated. Methadone is an opioid μ (MOR) receptor agonist, also a glutamate antagonist by blocking the N-methyl-D-aspartate (NMDA) receptor and a reuptake of serotonin and noradrenaline inhibitor. Intraoperative analgesia generated by administration of 20 to 30 mg methadone can last 24 to 36 hours. There is also evidence that methadone at 0.2 to 0.3 mg / kg is not associated with an increased incidence of side effects compared to other opioids with short or intermediate duration of action, such as fentanyl, sufentanyl and morphine.

The aim of this study is to evaluate the efficacy of intraoperative methadone in reducing postoperative pain and opioid consumption in patients undergoing open gastroplasty with or without associated Roux Y. Patients will undergo standardized general anesthesia, and the opioid used in anesthesia induction is methadone 0.15 mg / kg fentanyl or 6 mcg / kg bolus with additional if necessary. After extubation a intravenous morphine patient controlled analgesia device will be already available in the operating room. Groups will be compared regarding opioid consumption, pain scores, side effects, patient satisfaction and development of chronic postoperative pain.

Study Type

Interventional

Enrollment (Actual)

32

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Brazil
      • Sao Paulo, Brazil, 05403-000
        • Hospital das Clinicas da FMUSP

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Open bariatric surgery
  • No contraindications for any drugs used during the trial
  • Read, understood and signed the informed consent

Exclusion Criteria:

  • Laparoscopic bariatric surgery
  • Known allergy to any drugs used during the trial
  • Cardiovascular disease
  • Creatinine clearance lower than 60 mL/min/1.73 m2
  • Chronic usage of opioids
  • History of personality disorder

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Methadone
Methadone used as anesthesia opioid: induction with 0,15 mg / kg intravenous methadone. Boluses of 0,05 mg / kg intravenous methadone as needed intraoperatively
Drug: Use of Intraoperative Intravenous Methadone
The intervention group will be given intravenous methadone at a fixed induction dose (0,15 mg / kg) and intraoperative boluses as judged necessary by the anesthesiologist
Other Names:
  • Methadone
Active Comparator: Fentanyl
Fentanyl used as anesthesia opioid: induction with 6 mcg / kg intravenous fentanyl. Boluses of 2 mug / kg intravenous fentanyl as needed intraoperatively
Drug: Use of Intraoperative Intravenous Fentanyl
The active control group will be given intravenous fentanyl at a fixed induction dose (6 mg / kg) and intraoperative boluses as judged necessary by the anesthesiologist
Other Names:
  • Methadone

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postoperative Pain
Time Frame: Until 3 months postoperatively
Postoperative pain will be evaluated using a verbal numerical pain scale (ranging from 0 to 10)
Until 3 months postoperatively

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postoperative opioid consumption
Time Frame: Until 3 months postoperatively
Postoperative opioid consumption will be evaluated at fixed postoperative times: 2h, 6h, 24h, 48h, 72h and 3 months
Until 3 months postoperatively
Side effects
Time Frame: Until 3 months postoperatively
Nausea, vomiting, itching, urinary retention, respiratory depression, sedation will be evaluated at fixed postoperative times: 2h, 6h, 24h, 48h, 72h and 3 months
Until 3 months postoperatively
Chronic postoperative pain
Time Frame: 3 months postoperatively
Patients will be evaluated for chronic pain 3 months postoperatively through a questionnaire which includes questions about numerical verbal scale of pain in the last three months, analgesic consumption and satisfaction with analgesia regimen
3 months postoperatively

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Sao Paulo General Hospital

Investigators

  • Study Chair: Claudia Palmeira, MD, PhD, University of Sao Paulo General Hospital
  • Study Director: Hazem Ashmawi, MD, PhD, University of Sao Paulo General Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

June 1, 2016

Primary Completion (Actual)

January 1, 2017

Study Completion (Actual)

January 1, 2017

Study Registration Dates

First Submitted

May 12, 2016

First Submitted That Met QC Criteria

May 16, 2016

First Posted (Estimate)

May 17, 2016

Study Record Updates

Last Update Posted (Estimate)

January 26, 2017

Last Update Submitted That Met QC Criteria

January 25, 2017

Last Verified

January 1, 2017

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 52792616.9.0000.0068

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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