Predictors of Perioperative Opioid Use in Hysterectomy Patients.

Background and Objectives: Little is known about predictors of opioid use in the acute postoperative phase after hysterectomy. Inadequate pain support during this time can result in increased postoperative complications, and persistent postoperative pain. Objective is to determine predictors of increased opioid use in the acute perioperative phase (intraoperatively and 1 hour and 24 hours postoperatively). Methods: A prospective cohort study involving 200 participants undergoing nonurgent hysterectomy via laparoscopic, vaginal, abdominal, or robotic approaches at an academic tertiary hospital in Toronto, Canada. Data collected included demographics, preoperative validated pain questionnaire scores, pain scores at 1 and 24 hours postoperatively, and analgesic medications used. Nonparametric statistical methods and multivariate analyses were used to examine the association between clinical predictors and opioid use. Opioid use was converted into morphine equivalent dose (MED). Results: Pain sensitivity questionnaire (PSQ) score and body mass index were strongly associated with increased intraoperative MED. Twenty-four-hour postoperative opioid use was negatively correlated to age. Multivariate analysis identified PSQ total score and open hysterectomy as predictors of higher intraoperative MED. The number of preoperative pain medications, open hysterectomy, and PSQ total score were significant predictors of total MED requirements. One additional pain medication and one additional total PSQ point were associated with an increase in total MED of 10.76 and 5.17 mg, respectively. Conclusions: This study is the first step in identifying clinical predictors of increased opioid requirements in the first 24 hours postoperatively. These predictors can inform patient-tailored management plans to ensure adequate pain support and appropriate opioid use.