QUALITY OF RECOVERY AFTER INTRAOPERATIVE MORPHINE OR METHADONE

Introduction. Despite the advantages associated with the use of remifentanil during total intravenous anesthesia (TIVA), it has been observed a frequent difficulty in the control of postoperative pain due to the risk of developing hyperalgesia and acute tolerance associated with the administration of this opioid. There is evidence that NMDA receptors are involved in the development of these changes. Methadone is an opioid that exhibits analgesic potency similar to that of morphine but has NMDA antagonist activity and longer duration of action as additional features. The objective of the study was to evaluate the quality of recovery (QoR40) of patients undergoing TIVA for laparoscopic cholecystectomy and who received morphine or methadone to control postoperative pain. Methods. Patients aged 18 to 65 years, physical status ASA I and II, submitted to total venous anesthesia (propofol and remifentanil) for laparoscopic cholecystectomy and eligible to participate in this prospective and randomized clinical study will be evaluated. After induction of anesthesia, patients will receive a solution containing 0.1 mg.kg-1 morphine (MF group) or 0.1 mg.kg-1 methadone (MT group). Data on the presence of pain, nausea, vomiting, tremor, drowsiness, presence of SpO2 \<92%, even with O2 face mask (5 L.min-1) and length of stay will be recorded at PACU. The pain will be evaluated every 15 minutes on a verbal numerical scale (ENV) from 0 to 10. E.v. morphine 0.1 mg.kg-1 (MF group) or methadone 0.1 mg.kg-1 (MT group) will be administered every 15 minutes to obtain the score below 3. After discharge from the PACU, all patients will receive intravenous ketoprofen every 12 hours and dipyrone every 6 hours. For cases where the patient considers the analgesic regimen insufficient, tramadol (100 mg) will be administered intravenously at 8-hour intervals. The consumption of analgesics, the intensity of pain, the occurrence of nausea, vomiting and other complications in the ward will be recor