Accuracy of patient-reported versus real-time electronic postoperative opioid use outcomes

Interactions Between Endocannabinoid and Endogenous Opioid Systems Prospectively Influence Postoperative Opioid Use in Pregnant Patients Undergoing Cesarean Delivery

Both endocannabinoid (EC) and endogenous opioid systems are involved in nociceptive processing and may work together synergistically based on preclinical models. This study evaluated the interactive effects of preoperative beta-endorphin (BE) concentrations (a key analgesic endogenous opioid) in cerebrospinal fluid (CSF) and ECs (CSF and plasma 2-arachidonoylglycerol and plasma anandamide) on postoperative opioid use and pain intensity in a prospective cohort of n = 112 pregnant patients undergoing scheduled cesarean delivery. Maternal blood and CSF samples were collected preoperatively for BE and EC assays. Patients completed measures of outpatient opioid use (number of tablets used and days of use) and average pain intensity at 2 weeks postoperatively. Results of general linear model analyses controlling for maternal age, body mass index at time of delivery, and race revealed significant multiplicative interactions between EC and BE concentrations on number of opioid tablets used (based on pill count), days of opioid use, and total milligram morphine equivalents used in the 2-week follow-up period. Elevated preoperative plasma and CSF 2-arachidonoylglycerol predicted reduced outpatient opioid analgesic use, particularly for patients low in CSF BE. Similar analyses for pain intensity at 2-week follow-up indicated a significant interaction (P < .02) characterized by higher preoperative BE concentrations being associated with lower subsequent pain only for individuals with low preoperative plasma anandamide concentrations. Further exploration of interactions between EC and endogenous opioid inhibitory systems as they influence responses to opioid analgesics in other clinical pain populations may help guide the development of precision pain management approaches. PERSPECTIVE: In the postoperative setting of patients undergoing cesarean delivery, elevated ECs were linked to reduced outpatient opioid analgesic use in individuals who had low endogenous opioid concentrations in CSF. Further exploration of interactions between these 2 inhibitory systems as they impact responses to pain management interventions appears warranted.

Electronic Real-Time Monitoring Reveals Limited Adherence to Long-Term Opioid Prescriptions in Pain Patients

Background

Pain management physicians are increasingly focused on limiting prescription opioid abuse, yet existing tools for monitoring adherence have limited accuracy. Medication event monitoring system (MEMS) is an emerging technology for tracking medication usage in real-time but has not been tested in chronic pain patients on long-term opioid regimens.

Objective

We conducted a pilot clinical trial to investigate the utility of MEMS for monitoring opioid adherence and compared to traditional methods including self-report diaries, urine drug screen (UDS), and physicians' opinions.

Methods

Opioid-maintained chronic pain patients were recruited from a pain management clinic. Participants (n=28) were randomly assigned to either receive MEMS bottles containing their opioid medication for a 90-day period or to continue using standard medication bottles. MEMS bottles were configured to record and timestamp all bottle openings and the number of pills that were removed from the bottle (via measurement of weight change).

Results

Participants who received MEMS demonstrated highly heterogenous dosing patterns, with a substantial number of patients rapidly removing excessive amounts of medication and/or "stockpiling" medication. By comparison, physicians rated all participants as either "totally compliant" or "mostly compliant". UDS results did not reveal any illicit drug use, but 25% of participants (n=7) tested negative for their prescribed opioid metabolite. MEMS data did not correlate with physician-rated adherence (P=0.24) and UDS results (P=0.77). MEMS data consistently revealed greater non-adherence than self-report data (P<0.001).

Conclusion

These results highlight the limits in our understanding of naturalistic patterns of daily opioid use in chronic pain patients as well as support the use of MEMS for detecting potential misuse as compared to routine adherence monitoring methods. Future research directions include the need to determine how MEMS could be used to improve patient outcomes, minimize harm, and aid in clinical decision-making.

Trial Registration

This study was preregistered on ClinicalTrials.gov (NCT03752411).

Prospective evaluation of cerebrospinal fluid levels of β-Endorphin as a predictor of opioid use after scheduled cesarean delivery

Background

Prior laboratory work indicates that lower endogenous opioid function is associated with greater analgesic and subjective responses to opioid analgesics. We evaluated whether lower preoperative cerebrospinal uid (CSF) levels of the analgesic endogenous opioid β-Endorphin (BE) were associated with increased opioid use after cesarean delivery (CD).

Methods

We enrolled 136 pregnant women without opioid use or chronic pain who were undergoing CD under regional anesthesia. Preoperatively, participants completed validated pain measures and biospecimens were collected to assess BE levels in plasma and CSF. Postoperatively, pain measures at 48 hours and 2 weeks postpartum were assessed. We evaluated the association between CSF BE levels and total opioid use (in morphine milligram equivalents; MMEs) using linear regression controlling for confounding factors (primary analysis). In secondary analyses, we examined: 1) associations between plasma BE levels and total opioid use, and 2) associations between CSF and plasma BE levels and secondary outcomes (inpatient versus outpatient opioid use, pain intensity).

Results

Participants completed surveys with 100% response rate. The majority were non-Hispanic white (65%), college educated (58%), had private insurance (71%), and had a prior cesarean delivery (69%). Psychiatric diagnoses (depression or anxiety) were common, both currently (22%) and in the past (26%).The median total opioid use across the inpatient and 2-week postpartum follow-up period was 89.1 milligram morphine equivalents (IQR 25-138). Preoperative cerebrospinal uid β-Endorphin levels were not associated with total opioid use (beta = -0.05, SE 0.45, p = 0.64). Similar findings were noted for plasma β-Endorphin levels. cerebrospinal uid β-Endorphin levels were only weakly correlated with plasma β-Endorphin levels (r = 0.30, p < .01). Preoperative cerebrospinal uid and plasma β-Endorphin levels were both positively associated with postpartum pain measures (cerebrospinal uid: at 48 hours, beta = 0.19, SE 0.16, p < 0.05; Plasma: at 48-hours, beta = 0.02, SE 0.03, p = 0.02, and at 2-weeks, beta = 0.27, SE 0.03, p < 0.01).

Conclusions

Lower preoperative cerebrospinal uid levels of β-Endorphin are not associated with increased opioid analgesic use after scheduled cesarean delivery. It is possible that unassessed variability in baseline opioid receptor sensitivity may have confounded ability to test associations between β-Endorphin levels and opioid use outcomes.

Development and Validation of a Model to Predict Postdischarge Opioid Use After Cesarean Birth

A model with three predictors readily found in the electronic health record—inpatient opioid use, tobacco use, and depression or anxiety—accurately estimated postdischarge opioid use.

OBJECTIVE:

To develop and validate a prediction model for postdischarge opioid use in patients undergoing cesarean birth.

METHODS:

We conducted a prospective cohort study of patients undergoing cesarean birth. Patients were enrolled postoperatively, and they completed pain and opioid use questionnaires 14 days after cesarean birth. Clinical data were abstracted from the electronic health record (EHR). Participants were prescribed 30 tablets of hydrocodone 5 mg–acetaminophen 325 mg at discharge and were queried about postdischarge opioid use. The primary outcome was total morphine milligram equivalents used. We constructed three proportional odds predictive models of postdischarge opioid use: a full model with 34 predictors available before hospital discharge, an EHR model that excluded questionnaire data, and a reduced model. The reduced model used forward selection to sequentially add predictors until 90% of the full model performance was achieved. Predictors were ranked a priori based on data from the literature and prior research. Predictive accuracy was estimated using discrimination (concordance index).

RESULTS:

Between 2019 and 2020, 459 participants were enrolled and 279 filled the standardized study prescription. Of the 398 with outcome measurements, participants used a median of eight tablets (interquartile range 1–18 tablets) after discharge, 23.5% used no opioids, and 23.0% used all opioids. Each of the models demonstrated high accuracy predicting postdischarge opioid use (concordance index range 0.74–0.76 for all models). We selected the reduced model as our final model given its similar model performance with the fewest number of predictors, all obtained from the EHR (inpatient opioid use, tobacco use, and depression or anxiety).

CONCLUSION:

A model with three predictors readily found in the EHR—inpatient opioid use, tobacco use, and depression or anxiety—accurately estimated postdischarge opioid use. This represents an opportunity for individualizing opioid prescriptions after cesarean birth.

Opioid use in patients with peripheral arterial disease undergoing lower extremity bypass

OBJECTIVE

Opioid use is common among patients with peripheral arterial disease (PAD), given that pain is a defining symptom. Unfortunately, long-term opioid use places patients at dramatically increased risk of overdose and death. Although surgical revascularization is extremely effective in alleviating ischemic pain related to PAD, it is unclear whether this practice results in the discontinuation of opioids after surgery. Therefore, we conducted the following study to investigate trends in opioid use before and after surgical bypass in patients with PAD, as well as the risk factors for continued opioid use after surgery.

METHODS

We conducted a retrospective analysis of patients undergoing open lower extremity bypass for claudication or rest pain between June 1, 2017, and March 31, 2021. Patients were grouped according to whether they reported preoperative opioid use at the time of surgery. The primary outcome was continued opioid use at 30-day follow-up after discharge. A multivariable logistic regression was conducted to estimate the association of continued opioid use with patient characteristics, preoperative opioid use, and receiving a postoperative opioid prescription.

RESULTS

Among 3873 patients undergoing surgery, the mean age was 65.7 (10.2) years and 2650 (68.4%) patients were male. There were 913 patients (23.6%) who used opioids preoperatively and hydrocodone was the most common preoperative opioid (583 [63.9%]). At discharge, 2506 patients (64.7%) received a postoperative opioid prescription. Postoperative opioid prescriptions were significantly more common for preoperative opioid users than opioid-naïve patients (813 [89.0%] vs 1693 [57.2%]; P < .001) and were significantly larger in size (24.3 [21.1] pills vs 19.9 [10.5] pills; P < .001). On 30-day follow-up, 522 preoperative opioid users (61.3%) and 616 opioid-naïve patients (28.4%) reported that they were still using opioids (P < .001). Continued opioid use at follow-up was associated with preoperative opioid use (adjusted odds ratio, 3.23; 95% confidence interval, 2.70-3.89) and receiving a postoperative opioid prescription (adjusted odds ratio, 10.83; 95% confidence interval, 7.96-15.06).

CONCLUSIONS

Most patients with PAD who use opioids preoperatively do not discontinue opioids after lower extremity bypass. Moreover, a significant proportion of previously opioid-naïve patients are still using opioids 1 month after surgery. In both cases, postoperative opioid prescriptions had the strongest association with continued opioid use. These findings underscore the need for improved prescribing practice and increased attentiveness to discontinuation of unnecessary medications after surgery.