The Effects of One-time Intraoperative Methadone During Laparoscopic Hysterectomy in Reducing Opioid Prescription.

Problem:

The relief of moderate to severe postoperative pain in surgeries including abdominal surgeries continues to pose a major therapeutic dilemma. The traditional and most common therapy is the administration of short-acting opioid analgesics, intra-operative and post-operative, at intervals every 3-4 hours. However, the use of opioids with relatively short plasma half-lives at varying intervals may lead to various fluctuating drug concentrations in plasma, and side effects including respiratory, longer hospitalizations, delayed ambulation, inadequate pain relief and potential avenues for abuse. Identifying a more efficient and safer therapy for intraoperative pain analgesia can be helpful in controlling pain requirements in the post-operative setting.

In major inpatient and ambulatory surgeries, intraoperative single-dose methadone, through its unique pharmacology, has been shown to produce better analgesia, reduce opioid use and minimize adverse side effects compared with conventional repeated dosing of short-duration opioids. Additionally, methadone is theorized to be an N-methyl-D-aspartate (NMDA) receptor noncompetitive antagonist, which may contribute to its increase in analgesic potential as compared with fentanyl analogues. Finally, it has been shown to improve ambulation in the post operative anesthesia setting and pain control in chronic pain patients. The study of intra-operative methadone has not been extensively studied for gynecology surgeries, but one study has shown the decrease of mean opioid consumption post operatively after receiving one dose of intra-operative methadone compared to shorter acting opioids in same-day laparoscopic myomectomy. Given the increasing opioid abuse and over-prescription post-operatively, an effort should be made to determine whether one time dosing of longer opioid analgesics intra-operatively is an adequate potential in treating postoperative pain after hysterectomy surgeries and could minimize the need for additional post-operative and outpatient opioid prescriptions.

This study aims at addressing the requirement for postoperative opioid prescription after intraoperative longer acting vs shorter acting opioids in laparoscopic hysterectomy.

Hypothesis:

Single dose of intra-operative methadone is an adequate potential in treating post-operative pain after laparoscopic total hysterectomy surgeries, reducing the additional need for post-operative and outpatient opioid prescriptions and decreasing the adverse effects associated with opioid consumption.

Importance of research:

Given the increasing opioid abuse and over-prescription post-operatively, an effort must be made to determine whether one time dosing of longer opioid analgesics intraoperatively in conjunction with non-opioid multimodal medications is adequate to treat postoperative pain after laparoscopic hysterectomy. Additionally, this intervention may decrease the need for additional prescriptions or unscheduled patient contacts.

Inclusion criteria

• Individuals with a uterus
• Age 18 years old and above
• Undergoing minimally invasive (laparoscopic or robotic) hysterectomy with ovarian preservation
• Benign indications for hysterectomy
• Agreeing to participate

Exclusion criteria

• Chronic pain syndromes patients including fibromyalgia
• Patients currently on long-term (i.e. for more than three months) opioid use
• Patients currently on agonist-antagonist medications (e.g. buprenorphine)
• Patients taking a selective serotonin reuptake inhibitor or monoamine oxidase inhibitor
• Conversion to laparotomy
• Allergy or other contraindication to the prescribed medications such as methadone, fentanyl, acetaminophen or oxycodone
• Severe Obstructive Sleep Apnea (OSA)
• Pregnant/breastfeeding patients