Postdischarge Opioids and the Opioid Epidemic
New Persistent Postoperative Opioid use and Opioid use Disorder
Substantial rates of persistent postoperative opioid prescribing in previously opioid-naïve patients have been identified in nearly every surgical cohort,[3–6] albeit with highly variable definitions of this phenomenon. For example, 7.7% of patients older than 65 yr undergoing minor surgery continue being prescribed opioids during the first postoperative year, while 3.1% of patients undergoing cardiac, thoracic, intraabdominal, and pelvic surgeries have an opioid prescription dispensed 90 days or more postoperatively. Other investigators have identified rates of 2.2% at 6 months in retrospective data encompassing 1.35 million patients undergoing any type of in-hospital surgery,[8,9] 4.3 to 8.3% for prospectively collected, self-reported opioid use 6 months after total knee and hip arthroplasty, approximately 6% for an opioid prescription received 90 to 180 days after a variety of major and minor surgeries, and—perhaps most alarmingly—4.8% for an opioid prescription received during the 90 to 180 days after common pediatric surgeries.
Traditionally, opioids have been a mainstay of treatment for postoperative acute pain and have been prescribed with the assumption that patients will cease use once postoperative pain resolves. However, patients typically stop opioid use long before pain cessation occurs.[12,13] Studies have shown that among those with persistent opioid use, surgeons are rarely the prescribers more than 3 months after surgery. While some of the persistent opioid prescribing could be due to nonsurgical issues, claims data studies using nonsurgical control cohorts found much higher rates among those undergoing surgery, suggesting surgery and postoperative prescribing as the triggering event.[5,6] Some of the persistent opioid prescribing would also be expected to be attributable to new chronic postsurgical pain, but studies have shown similar prescribing rates after both major and minor surgery and no association with change in self-reported pain after joint arthroplasty. Thus, the driving factors for postoperative opioid consumption may extend beyond postoperative pain intensity and the direct treatment of surgical pain to encompass misuse for preexisting pain conditions, sleep, anxiety, and other patient-level factors (see "Preoperative Considerations" section).
It is important to note that significant data heterogeneity exists regarding new persistent postoperative opioid use incidence. Much of this variance appears to depend on the stringency of the definition used and the cohort evaluated: studies of new persistent postoperative opioid use have observed incidence of this condition ranging from 0.01 to 14.7%.[7,16] While there are prospective studies showing rates of 4 to 8% after surgery, gaining a deeper understanding of the association between chronic postoperative opioid use and these negative opioid-related outcomes will likely require moving beyond examining administrative claims and electronic health record data through which prescribing and consumption cannot be distinguished into large longitudinal cohorts of individual patients. This approach would also permit more granular study of opioid consumption rather than prescribing or prescription fills. Some working groups have suggested definitions for persistent opioid use; however, the cutoffs suggested are subject to similar critique as the more commonly published definitions and potentially offer greater specificity at the cost of lower sensitivity. Consensus definitions need to account for the data source (prospective, administrative, or prescription fulfillment data) and preoperative opioid status. Planned sensitivity analyses testing multiple definitions would allow for comparisons between studies and avoid the challenges of a "consensus" definition by a given group.
It is important to recognize that persistent opioid use is not synonymous with opioid use disorder (the diagnostic term for addiction), and that further research is needed to characterize the prevalence of opioid use disorder directly resulting from persistent postoperative opioid use. Similar research is needed to characterize the prevalence of postoperative opioid misuse and its relation to persistent postoperative opioid use. One obstacle to such research is that opioid use disorder is generally underrecognized and frequently goes undocumented in the electronic health record, where this diagnosis is seen much less frequently compared with the true prevalence of the condition.[7,19–22] The undercounting of patients with opioid use disorder or misuse may be particularly salient to surgical patients, in whom opioid misuse rates more than seven times greater than the general population have been reported (albeit in a cohort of joint reconstruction and spine patients in whom opioid use is more common).
Among opioid-naïve patients presenting for surgery, increasing numbers of refills and the duration of postoperative opioid use are strongly associated with the development of opioid misuse, and prescribing smaller amounts of opioids after surgery and limiting refills in the context of optimized perioperative pain management are warranted. However, the causality of this relationship has not been established; it may be due to patient-level factors, such as preoperative pain, sleep, and mood, rather than opioid consumption itself. Additionally, care must be taken to avoid stigmatizing particular populations based on racial, ethnic, and sociodemographic factors. To decrease the potential for this, patients can be assessed preoperatively for risk for substance use disorder in a standardized, high-throughput manner and referred for specialized addiction medicine evaluation, if indicated.
Persistent Postoperative Opioid use is More Common in Preoperative Opioid Users
Not surprisingly, preoperative opioid use is associated with longer durations of postoperative opioid prescribing, more refills after surgery, and increased postoperative daily oral morphine equivalent consumption.[25,26] It is also a clear risk factor for chronic postoperative opioid use.[10,27–31] Between 64 and 77% of chronic opioid users before surgery continue to fill opioids postoperatively.[28,29] This is particularly concerning in the context of surgery performed to address chronic pain, as there may be an expectation that opioid consumption will cease after surgery. In a prospectively collected cohort of patients undergoing arthroplasty who reported opioid use preoperatively, those reporting preoperative opioid use for another pain complaint beyond their knee or hip pain had an adjusted 2.4 times increased odds of self-reported opioid use 3 months after arthroplasty. Additionally, higher preoperative opioid doses and longer duration of preoperative use lead to increased risk of chronic use and continued opioid prescription fulfillment postoperatively.[10,33] Most concerning is the association of preoperative opioid prescription fulfillment with increased mortality, morbidity, and postoperative healthcare utilization.[35,36] These mortality and morbidity findings may be related to increased infectious risk secondary to opioid-induced immunosuppression. Given that more than 20% of patients presenting for elective surgery are already prescribed opioids, evidence-based interventions, prescribing guidelines, and policies should be developed for these patients that are distinct from those for opioid-naïve patients as their expected trajectories of postoperative opioid use likely differ.
Excess Opioid Prescribing
Excessive postsurgical opioid prescribing can result in a surplus of medications, increasing the possibility of diversion and misuse.[39,40] Surgeons' share of first-start opioid prescriptions to opioid-naïve patients increased more than 18% from 2010 to 2016, likely as a result of the increasing attention paid to opioid prescribing by primary care physicians. A 2017 study of opioid prescribing after five outpatient surgeries revealed wide variation in the number of pills prescribed for the same surgery; overall, surgical patients included in a 2017 systematic review took only 29 to 58% of prescribed opioid pills.
The issue of perioperative opioid overprescribing has substantial societal consequences. Among U.S. adults reporting opioid misuse or opioid use disorder in 2015, 36% obtained the opioids for their most recent misuse from their own prescription, and 47% from a friend or relative's prescription. This brings into focus the need for strategies such as storage education and home disposal kits to decrease opioid diversion.
While excess prescribing of opioids is a societal concern, untreated postsurgical pain and the acute to subacute to chronic pain transition represent major unmet needs for further research.[44,45] A recent systematic review and meta-analysis in this journal emphasized the lack of high-quality evidence available regarding pharmacotherapy for the prevention of these conditions. Advancements in personalized perioperative pain care may enable identification of suboptimal pain trajectories and preemptive treatment of patients at risk for development of chronic postsurgical pain; the large-scale National Institutes of Health Common Fund–supported Acute to Chronic Pain Signatures network (https://a2cps.org/) aims to address this research need.[47–50] Simpler acute pain descriptors may also prove helpful: Pain intensity predicts remote pain resolution, opioid cessation, and patient-reported surgical recovery when assessed 10 days after both major and minor operations conducted under either general or local anesthesia.[49,51] However, it is noteworthy that decades of excess postdischarge opioid prescribing demonstrate that liberal opioid administration is unlikely to address the issue of persistent postsurgical pain. Furthermore, multiple studies have shown little or no association between pain scores and the amount of opioid prescribed after surgery. This suggests that for the majority of patients who undergo surgery, conservative opioid prescribing can reduce the overall excess of unused prescription opioids without worsening postoperative pain-related outcomes.[52–56] While there are likely some surgeries for which opioids do not need to be prescribed routinely, they remain a cornerstone of acute postoperative pain management. Anecdotal reports of surgeons refusing to prescribe opioids based on institutional pressures or misapplication of state and federal policies and guidelines are concerning. It is critical that anesthesiologists and surgeons continue to attend to the pain needs of patients with opioids as appropriate.
While many anesthesiologists in the United States may feel disconnected from postsurgical opioid prescribing and pain management, it is important to recognize that anesthesiologists in other countries, including Australia and many European countries, are responsible for postdischarge prescribing.[57,58] Moreover, given the increased interest in transitional pain services and the perioperative surgical home in the United States and Canada,[59–62] the role of anesthesiologists in prescribing opioids, identifying risk, and counseling patients on safe use, storage, and disposal is likely to grow in the coming years.
Anesthesiology. 2022;136(4):594-608. © 2022 American Society of Anesthesiologists | Lippincott Williams & Wilkins