J. R. Imbus1, J. L. Philip1, J. S. Danobeitia1, D. F. Schneider1, D. Melnick1 1University Of Wisconsin,Surgery,Madison, WI, USA
Introduction: Surgeons typically prescribe opioids for patients undergoing outpatient general surgery operations, yet opioid prescribing practices are not standardized. Excess opioid supply in the community leads to abuse and diversion. Identifying patient and operative characteristics associated with postoperative opioid use could reduce overprescribing, and optimize prescribed quantity to patient need. Our aim was to characterize prescribing practices and opioid use after common outpatient general surgery operations, and to investigate predictors of opioid amount used.
Methods: We developed a postoperative pain questionnaire for adult patients undergoing outpatient inguinal hernia repair (IHR), laparoscopic cholecystectomy (LC), breast lumpectomy +/- sentinel lymph node biopsy, and umbilical hernia repair (UHR) at our institution. This facilitated a retrospective review of patients undergoing operations from January to May 2017, excluding those with postoperative complications. We collected opioid prescription data, operative details, and patient characteristics. All opioids were standardized to morphine milligram equivalents (MME) and reported as a corresponding number of 5mg hydrocodone pills for interpretability. Multivariable linear regression was used to investigate factors associated with opioid use.
Results: The 374 eligible cases included 114 (30.6%) unilateral and 59 (15.8%) bilateral IHRs, 90 (24%) LCs, 17 (4.6%) lumpectomies, 33 (8.9%) lumpectomies with sentinel node biopsy, and 60 (16.1%) UHRs. Forty-eight providers prescribed six different opioids. There was variation in prescribed quantity for all procedures, ranging from zero to 80 pills. Median numbers of pills prescribed vs taken were 20 vs 5.5 for unilateral IHR, 20 vs 4 for bilateral IHR, 20 vs 10 for LC, 10 vs 1 for lumpectomy, 20 vs 2 for lumpectomy with sentinel node biopsy, and 20 vs 5 for UHR. Most patients (86%) were over-prescribed. Nearly all (95%) patients took 30 or fewer pills. Twenty-four percent of patients took zero pills.
Univariate analysis showed operation type (p<.001), age (p<.001), body mass index (p<0.01), chronic pain history (p<0.01), and pre-operative opioid use (p<0.01) to be associated with MME amount taken. On multivariable analysis, there was a significant relationship between opioid use and age (p<0.001), with 16-34% less MME taken for every ten year age increase. Patients who underwent LC took over twice as much opioids compared to patients undergoing UHR (p<0.05). Opioid amount taken was independently associated with opioid amount prescribed (p<0.001), with patients taking 24% more MME for every additional ten pills prescribed.
Conclusion: Marked variation exists in opioid type and amount prescribed, and most patients receive more opioids than they consume. Higher prescription amounts contribute to more opioid use, and certain patient subsets may be more (LC) or less (elderly) likely to use opioids postoperatively.