Intraoperative Methadone for Postoperative Pain Control

Postoperative opioid use will be determined by the amount of morphine consumed (milligram morphine equivalents, MME) at 24 hours postoperatively

Total postoperative opioid use will be determined by the total amount of morphine consumed (milligram morphine equivalents, MME) at 48 hours postoperatively and during follow up visit

The number of respiratory interventions required postoperatively per patient in the PACU (Post-anesthesia care unit) will be determined

The average duration of hospitalization will be determined per patient

Patients perceptions of pain management will be measured by administration of the International Pain Outcomes (IPO) questionnaire on Post-Operative Day 1 (POD 1). IPO will be used to assess key patient level outcomes of postoperative pain management and consists of 13 questions evaluating four outcome domains: 1) intensity of pain rated on Numeric Rating Scale (NRS) score (0 = no pain, 10 = worst possible pain); 2) interference of pain with activities and emotional well-being as determined by a score analogous to the NRS 0-10 scale above; 3) side effects of pain treatment, including nausea, drowsiness, itching, and dizziness, as determined by the NRS score >0; and 4) perception of care, treatment satisfaction and involvement in pain treatment decision-making on a scale from 0-10. Scores are aggregated per patient with higher overall scores indicative of a worsening perception of pain management.

Patients perceptions of pain management will be measured by administration of the International Pain Outcomes (IPO) questionnaire on POD 1 (Post-Operative Day 1). IPO will be used to assess key patient level outcomes of postoperative pain management and consists of 13 questions evaluating four outcome domains: 1) intensity of pain rated on numeric rating score (0 = no pain, 10 = worst possible pain); 2) interference of pain with activities and emotional well-being as determined by a score analogous to the 0-10 scale above; 3) side effects of pain treatment, including nausea, drowsiness, itching, and dizziness, as determined by the NRS score >0; and 4) perception of care, treatment satisfaction and involvement in pain treatment decision-making on a scale from 0-10. Scores are aggregated per patient with higher overall scores indicative of a worsening perception of pain management.

Sedation score will be determined using the Pasero Opioid-induced Sedation Scale (POSS) in the Post-anesthesia Care Unit (PACU) and on the floor. Average scores will be tabulated per patient using a four point numeric rating scale. Scoring is as follows: 1 = Awake and alert; 2 = Slightly drowsy, easily aroused; 3 = Frequently drowsy, arousable, drifts off to sleep during conversation; 4 = Somnolent, minimal or no response to verbal and physical stimulation

Agitation and Sedation severity will determined using the Richmond Agitation-Sedation Scale (RASS) in the PACU and on the floor. Average scores will be determined per patient using a numeric rating scale ranging from +4 to -5 where +4 = combative, +3 = very agitated, +2 = agitated, +1 = restless, 0 = alert and calm, -1: = drowsy, -2 = light sedation, -3 = moderate sedation, -4 = deep sedation, and -5 = unarousable. Ideal RASS scores range from -1 to 1.

Opioid related side effects including nausea, vomiting, pruritis, urinary retention, and necessity of supplemental oxygen will be recorded

The average duration of time to first ambulation after surgery will be recorded per patient

The average duration of time to return of bowel function will be determined per patient

Procedure related adverse events or adverse events related to anesthesia will be recorded

Pain scores will be assessed by a research assistant blinded to the study group at regular intervals. Numerical pain scores (0=no pain, 10=most pain) will be assigned on an 11 point scale ranging from 0 (no pain) to 10 (most pain). Since most patients who get bariatric surgery are discharged at POD 1, the research assistant will call the patient the morning of POD 2 to assess the pain score if not on the inpatient floor. If the patients are not yet discharged, the pain score will be assessed the morning of POD 2, otherwise pain scores will be collected as detailed in the time frame below.