Background: While there is much evidence about pain management for orthopedic patients in the immediate perioperative setting, little is known about how opioids are used during inpatient rehabilitation, particularly in older adults. A safe upper limit of 50 mg oral morphine equivalents (OME) is frequently cited in guidelines.
Aim: The aim of this study was to characterize the dosing of opioids in an older adult population undergoing inpatient orthopedic rehabilitation (IOR).
Design: Retrospective observational study.
Setting: Inpatient units at an academic rehabilitation hospital in Toronto, Canada.
Population: All adults aged ≥50 years old admitted for orthopedic rehabilitation between November 2019 and June 2021 following acute care admissions for either a surgical or non-surgical orthopedic indication.
Methods: Participants were divided into groups of prior opioids users, new opioids users, and opioid non-users during IOR. Demographic, clinical, and medication administration data were collected through the electronic health record and manual chart review. Average daily opioid dose for the first seven days of each stay was characterized using OME. Linear regression was used to assess for variables independently associated with opioid dose.
Results: A total of 643 patients undergoing orthopedic rehabilitation were included: 125 (19.4%) were prior opioid users, 416 (64.7%) were new opioid users, and 102 (15.9%) were non-users, with median age respectively of 72, 79, and 83. Median daily OME over the first week for prior users was 30.3 and for new users was 6.9. Opioid dose was inversely associated with age and admission for a non-surgical indication; it was positively associated with reported pain (as defined by day 3 pain score) and admission for knee replacement.
Conclusions: Opioids are frequently but heterogeneously used in older adults undergoing IOR. Median OME use in this cohort of older adults was substantially lower than the 50 OME threshold suggested in guidelines, particularly for new opioid users.
Clinical rehabilitation impact: Older adults require much lower opioid doses than younger patients. Pain management in older orthopedic rehabilitation inpatients is distinct from the perioperative setting and deserves tailored guidance, with a focus on using the lowest effective dose.