Impact of Perioperative Epidural Placement on Postdischarge Opioid Use in Patients Undergoing Abdominal Surgery

Background: Opioids play a crucial role in providing analgesia throughout the perioperative period; however, patients may become persistent users of these medications months after surgery. Epidurals have been posited to prevent the development of persistent pain, but there are little data on the effect of epidurals on persistent opioid use. Methods: This study was conducted using a claims database of a large, nationwide commercial health insurer. Opioid-naive patients who underwent open abdominal surgery from January 2004 to December 2013 were included in the study. Propensity scores for epidural placement were calculated accounting for demographic characteristics, resource utilization, and comorbid conditions (including medical, psychiatric, and pain conditions). Time-to-event analysis was used with the primary outcome defined as 30 days without filling an opioid prescription after discharge. In addition, total morphine equivalents dispensed within 90 days of discharge were also calculated for each patient. Results: A total of 6,432 patients were included in the final propensity score-matched cohort. The Cox proportional hazards ratio was 0.96 (95% CI, 0.91 to 1.01; P = 0.0910) for the relation between epidural placement and time till a 30-day gap without filling an opioid prescription. There was no difference in the total morphine equivalents dispensed within 90 days of discharge between the groups (P = 0.7670). Conclusions: Epidural placement was not protective against persistent opioid use in a large cohort of opioid-naive patients undergoing abdominal surgery. This finding does not detract from the other potential benefits of epidural placement. More research is needed to understand the mechanism of persistent opioid use after surgery and its prevention.