Preoperative Opioid and Benzodiazepine Use: Influence on Abdominal Surgical Outcomes.

Background: Preoperative opioid use has shown association with worse outcomes after surgery. However, little is known about the effect of preoperative benzodiazepines with and without opioids. The aim of this study was to determine the influence of preoperative substance use on outcomes after abdominal surgery.