Pain Control and Quality of Recovery After Intravenous Methadone Versus Intrathecal Morphine in Major Abdominal Surgery

Quality of Recovery 15 score,Overall Benefits of Analgesic Score,morphine milligram equivalent,Verbal Rating Scale (VRS) pain scores

Moderate to severe postoperative pain is relatively common after major abdominal surgery. It
 is associated with less than optimal surgical experience, poor quality of recovery, and the
 development of persistent postsurgical pain. Opioids remain a significant component of
 postoperative pain management. Side effects of opioids used for the treatment of
 postoperative pain include constipation, pruritus, nausea, and vomiting. Enhanced recovery
 after surgery (ERAS) protocols involve the utilization of multimodal analgesia. Analgesic
 techniques used include epidural analgesia, nerve blocks, and Intrathecal (IT) administration
 of morph ne. IT morphine reduces the postoperative opioid requirement for 18-24 hours after
 major abdominal surgery and reduces hospital length of stay (LOS) compared with epidural
 analgesia. A significant number of patients who receive IT morphine still experience moderate
 to severe postoperative p in. Additionally, many patients refuse the invasive procedure or
 cannot receive IT morphine due to procedure contraindications, thrombocytopenia, and/or
 coagulopathy.
 
 Intravenous (IV) methadone has a long analgesic half-life and has N-methyl-D-aspartate (NMDA)
 receptor antagonist and serotonin and norepinephrine reuptake inhibitor (SNRI) properties. It
 has previously been shown to reduce postoperative opioid requirements, postoperative nausea
 and vomiting (PONV), and postoperative pain scores in patients who underwent orthopedic,
 abdominal, complex spine, and cardiac surg ry. Similar findings have been shown in obstetric
 patients who underwent cesarean delivery under general anesthesia as well as patients who
 underwent gynecologic surgery. IV methadone has, however, never been compared with IT
 morphine as a postoperative analgesic.
 
 The hypothesis is that intravenous (IV) methadone is non-inferior to IT morphine in patients
 who undergo major abdominal surg ry. It offers the advantage of being a noninvasive analgesic
 modality that may contribute to decreasing opioid consumption during the first 72 hours
 postoperatively, controlling postoperative pain, and improving the quality of recovery after
 surgery.