The Role of Preoperative Opioid Use in Foot and Ankle Surgery: A Systematic Review

Prescription opioids, particularly for treating musculoskeletal pain, are a significant contributor to the opioid epidemic in North America. There is also evidence to suggest that chronic use of opioids is associated with poor outcomes after orthopedic surgery. However, whether this association is relevant in foot and ankle surgery is still unclear. Accordingly, a systematic review of the literature was undertaken to assess the impact of preoperative opioid use in patients undergoing foot and ankle surgery concerning postoperative pain, complications, and postoperative opioid dependence. Four databases, including EMBASE, MEDLINE, PubMed, and CINAHL, were searched to March 2022 for studies reporting preoperative opioid use and its effect on postoperative outcomes or opioid use after foot and ankle surgery. A total of 22,092 patients were included in the final synthesis of 8 studies. Most of which were level 3 evidence (5 studies). Around 18% of the patients used opioids preoperatively. Preoperative opioid use was associated with more quantities and prolonged use of opioids postoperatively. Two studies showed an increased risk of complications postoperatively in patients who used opioids preoperatively compared to the nonopioid group. Preoperative opioid use in patients undergoing foot and ankle surgeries is associated with increased and prolonged use of opioids postoperatively and may therefore predict the potential for misuse.

Synergistic effect of combining dual enkephalinase inhibitor PL37 and sumatriptan in a preclinical model of migraine

OBJECTIVE

The aim of this study was to test whether a combination of sumatriptan with dual enkephalinase inhibitor PL37 would result in an additive or a synergistic effect.

BACKGROUND

Combination treatment is frequently used to improve the therapeutic efficacy of drugs. The co-administration of two drugs may result in efficacy at lower doses than those needed for either drug alone, thus minimizing side effects. Here, we tested the effect of the co-administration of two drugs on cutaneous mechanical hypersensitivity (MH), a symptom often affecting cephalic regions in patients with migraine: dual enkephalinase inhibitor PL37, a small molecule that protects enkephalins from rapid degradation, and sumatriptan, a serotonin 5-HT1B/1D receptor agonist.

METHODS

We investigated the effects of oral administrations of sumatriptan, PL37, or their combination on changes in cutaneous mechanical sensitivity induced by a single intraperitoneal administration of the nitric oxide donor, isosorbide dinitrate (ISDN) in male rats. Mechanical sensitivity was assessed using von Frey filaments applied to the face of animals to determine pain thresholds. Isobolographic analysis was performed to determine the nature of the interaction between sumatriptan and PL37.

RESULTS

Sumatriptan as well as PL37 each produced a dose-dependent inhibition of ISDN-induced cephalic MH. Median effective dose (ED50 ) values were 0.3 and 1.1 mg/kg for sumatriptan and PL37, respectively. An isobolographic analysis of the effect of combined doses of sumatriptan and PL37 based on their calculated ED50 values demonstrated a synergistic effect of the combination on cephalic MH, with an interaction index of 0.14 ± 0.04.

CONCLUSION

These results suggest that PL37 acts synergistically with sumatriptan to produce an anti-allodynic effect in a rat model of migraine. Thus, combining PL37 and sumatriptan may be a useful therapeutic strategy in the management of migraine.

PLAIN LANGUAGE SUMMARY

There have been many advances in migraine treatment, but we still need more options that are effective and have few side effects. Sumatriptan is one available drug for acute treatment of migraine, but it does not work for every patient and is not suitable for some people. We tested a new drug called PL37 (that blocks enkephalinases) together with sumatriptan and the combination minimized side effects and allowed lower doses of the drugs for effective migraine treatment in an animal model.

Reduced Opioid Use Among Patients Who Received Liposomal Bupivacaine Brachial Plexus Block for Total Shoulder Arthroplasty

Purpose This retrospective cohort explores the efficacy of regional shoulder blocks using Exparel™ in patients undergoing total shoulder arthroplasty (TSA)/reverse total shoulder arthroplasty (RSA) to reduce total opioid prescription, refills, and length of stay in the acute care setting. Methods Patients who underwent TSA/RSA by a single surgeon in a three-year period were evaluated. Patients in the case group received liposomal bupivacaine 1.3% brachial plexus block while the control group received ropivacaine 0.5% interscalene brachial plexus block. Outcomes of the study included the number of opioids taken, opioids prescribed, and length of hospital stay. Results Thirty-six patients underwent TSA/RSA between January 2017 and March 2020. Patients who received an Exparel brachial plexus block had decreased opioid use within the first 24 hours after surgery compared to the ropivacaine group, 9.00 ± 14.10 and 26.20 ± 24.8 morphine milligram equivalent (MME), respectively (p=0.0213). Patients who received an Exparel brachial plexus block had decreased opioid prescriptions over the entire postoperative follow-up, 411.00 ± 200.74 MME in the case group and 593.07 ± 297.57 MME in the control group (p=0.0314). Lastly, patients who received an Exparel brachial plexus block had a shorter length of hospital stay, 1.28 ± 0.91 days as compared to the control group's 2.15 ± 1.49 days (p=0.0451). Conclusion This study demonstrates a significant reduction in opioid prescribing and use in patients who receive Exparel brachial plexus nerve blocks compared to non-liposomal local anesthetics, as well as a significant reduction in the length of hospital stay. The data suggest that Exparel use may decrease the risks associated with opioid use while providing adequate analgesia in patients undergoing shoulder arthroplasty.

Danavorexton (TAK-925): an orexin receptor 2 agonist as a new 'arousal' agent

A preclinical study in animals has further characterised a new 'arousal' agent. Danavorexton (TAK-925) is an agonist for orexin receptor 2 where it promotes recovery from inhalational and i.v. anaesthesia and opioid sedation. Although danavorexton reverses opioid sedation, it does not compromise analgesia. This could be a useful addition to the postoperative drug cupboard.

Opioid Use Increases the Rate of Pseudarthrosis and Revision Surgery in Patients Undergoing Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective Cohort.

OBJECTIVES

To (1) quantify the risk opioids impart on pseudarthrosis development, (2) analyze the effect of pseudarthrosis on clinical outcomes, and (3) identify if the amount of opioids prescribed are predictive of pseudarthrosis revision.

METHODS

Patients who underwent ACDF at a single institution between 2017-2019 were retrospectively identified. Postoperative dynamic cervical spine radiographs were reviewed to assess fusion status. Logistic regression models measured the effect of morphine milligram equivalents (MME) prescribed on the likelihood of pseudarthrosis development. Receiver operating characteristic (ROC) curves were generated to predict the probability of surgical revision based on MME prescribed.

RESULTS

Of 298 included patients, an average of 2.01 ± 0.82 levels were included in the construct and 121 (40.9%) patients were diagnosed with a pseudarthrosis. However, only 14 (4.7%) required a pseudarthrosis revision. Patients requiring pseudarthrosis revision had worse one-year postoperative Δ PCS-12 (-1.70 vs. 7.58, P = 0.004), Δ NDI (3.33 vs. -15.26, P = 0.002), and Δ VAS Arm (2.33 vs. -2.48, P = .047). Multivariate logistic regression analyses found the three-month postoperative (OR=1.00, P = .010), one-year postoperative (OR=1.001, P = 0.025), and combined pre- and postoperative MME (OR=1.000, P = .035) increased the risk of pseudarthrosis. ROC analysis identified cutoff values to predict pseudarthrosis revision at 90.00 (area under the curve (AUC): 0.693, confidence interval (CI): 0.554-0.832), 132.86 (0.710, CI: 0.589-0.840), 224.76 (0.687, CI: 0.558-0.817) and 285.00 (0.711, CI: 0.585-0.837) MME in the preoperative, three-month postoperative, one-year postoperative, and combined pre-and postoperative period.

CONCLUSION

Increased prescription of opioid medications following ACDF procedures may increase the risk of pseudarthrosis development and revision surgery.

LEVEL OF EVIDENCE

Therapeutic Level III.

β-Endorphin influences sedative and ataxic effects of alcohol

Beta-endorphin (β-E) is an opioid peptide linked to the behavioral effects of ethanol. For example, β-E provides negative feedback to inhibit the hypothalamic-pituitary-adrenal (HPA) stress axis, and neuroadaptation of this system to ethanol may facilitate sex differences in disordered drinking. Locomotor sensitivity to ethanol may also influence the risk for addiction; however, the role of β-E in psychomotor effects of ethanol is not fully understood. We examined the role of β-E and sex on locomotor effects of ethanol using adult male and female wild-type C57BL/6J and β-E deficient B6.129S2-Pomctm1Low/J mice in a parallel rod floor apparatus following 0.75 or 2.0 g/kg ethanol. Beginning 15 min after intraperitoneal injection, we recorded foot slips, distance traveled, slips per meter, first instance of immobility, and total time spent off-balance (lying on the floor) over 15 min, and collected blood for analysis of ethanol concentration 60 min after injection. Overall, β-E deficient mice were more sedated and ataxic following ethanol; at the lower dose they slipped more frequently and had a higher rate of slips per meter traveled. At the higher dose, β-E deficient mice were predominantly sedated, slipping less frequently, and traveling less, as well as spending more time off-balance and becoming immobile sooner. Genotype interacted with sex in that male β-E deficient mice slipped more frequently than their female counterparts, suggesting that β-E may elicit sex-dependent effects of ethanol-induced ataxia. Blood ethanol concentration did not differ between any group, suggesting that behavioral differences result from altered sensitivity to ethanol. Our data support the contention that β-E modulates the locomotor effects of ethanol and may influence ataxia in a sex-dependent manner. These findings help elucidate the role of β-E in diverging behavioral responses to ethanol and may aid the development of targeted treatments for alcohol use disorders.

Analysis of Nausea and Vomiting Frequency Following Opioid Dose Escalation and Its Risk Factors: A Single-Center Retrospective Observational Study

Background and Objective: Opioid-induced nausea and vomiting (OINV) is known to develop not only upon opioid introduction but also during opioid dose escalation, but the actual details are unclear. The aim of this study was to investigate the frequency of OINV in opioid dose escalation at a single center and to identify risk factors. Methods: A retrospective analysis of the medical records of hospitalized patients with cancer who underwent increased intake of oral oxycodone extended-release tablets at Komaki City Hospital between January 2016 and December 2019 was performed. Associations between the incidence of OINV and multiple factors were analyzed, including patient demographics, opioid daily dose, comorbidities, history of nausea after opioid introduction, and prophylactic antiemetic drugs. Results: Of the 132 patients analyzed, 56 (42.4%; grades 1 and 2, 36 and 20, respectively) developed opioid-induced nausea after opioid dose escalation, 26 (19.7%; grades 1 and 2, 19 and 7, respectively) developed opioid-induced vomiting, 58 (43.9%) had either opioid-induced nausea or vomiting. Thirty-five of 60 patients (55.0%) developed OINV among those who received prophylactic antiemetic drugs at opioid dose escalation. Performance status (≥2) (odds ratio [OR]: 2.36, 95% confidence interval [95% CI]: 1.15-4.84, p = 0.02) and history of nausea for opioid introduction (OR: 2.92, 95% CI: 1.20-7.10, p = 0.02) were detected as risk factors for the development of OINV. Conclusion: This study revealed a high incidence of OINV during opioid dose escalation, indicating that careful monitoring is required as at the time of opioid introduction. Further validation by a prospective study is required.

No-Opioid Discharge Following Artificial Urinary Sphincter Placement Does Not Significantly Increase Health Care System Burden

INTRODUCTION

Postoperative opioid prescriptions are associated with an increased risk of opioid dependance. While studies on no-opioid discharge strategies have been assessed following many urologic procedures, the effect of no-opioid discharges on health care utilization following artificial urinary sphincter placement is unknown. We performed a single-surgeon retrospective comparison of health care system interactions following artificial urinary sphincter implantation between patients who received an opioid prescription on discharge to those who did not.

METHODS

We identified 101 male patients who underwent 3-piece artificial urinary sphincter placement or revision by 1 provider between 2015 and 2022. All patients were discharged with acetaminophen and ibuprofen; none received intraoperative local anesthetic. Demographic information, preprocedural opioid use, opioid prescriptions following the procedure, postoperative office communications, unplanned office visits, and emergency department (ED) visits were recorded for each patient for 90 days.

RESULTS

Forty-five patients (45%) were discharged without an opioid prescription and 56 patients (55%) were discharged with an opioid prescription. No differences in age, race, BMI, operative time, or presence of a preoperative opioid prescription were observed. Discharge without an opioid did not significantly increase the number of office communications (55% vs 40%, P = .11), unplanned office visits (36% vs 23%, P = .19), or ED visits (20 vs 12, P = .41) within 90 days of implantation/revision.

CONCLUSIONS

Opioids can be omitted from the discharge analgesic regimen following artificial urinary sphincter placement without increasing burden to surgical office staff or local EDs. Providers should consider no-opioid discharges for patients undergoing uncomplicated sphincter placement to limit risk of opioid-related morbidity.

Opioid Switch Dosing in Chronic Cancer Pain: A Prospective Longitudinal Study

Background: Opioid switching is common, however, conversion tables have limitations. Guidelines suggest postswitch dose reduction, yet, observations show opioid doses may increase postswitch. Objectives: To document the opioid conversion factor postswitch in cancer, and whether pain and adverse effect outcomes differ between switched opioid groups. Design/Setting: This multicenter prospective longitudinal study included people with advanced cancer in Australia. Clinical data (demographics, opioids) and validated instruments (pain, adverse effects) were collected twice, seven days apart. Results: Opioid switch resulted in dose increase (median oral morphine equivalent daily dose 90 mg [interquartile range {IQR} 45-184] to 150 mg [IQR 79-270]), reduced average pain (5.1 [standard deviation {SD} 1.7] to 3.8 [SD 1.6]), and reduced adverse effects. Hydromorphone dose increased 2.5 times (IQR 1.0-3.6) above the original conversion factor used. Conclusions: Opioid switching resulted in overall dose increase, particularly when switching to hydromorphone. Higher preswitch dosing may require higher dose conversion ratios. Dose reduction postswitch risks undertreatment and may not be always appropriate.

The Association Between Self-Reported Anxiety and Retention in Opioid Agonist Therapy: Findings From a Canadian Pragmatic Trial

BACKGROUND

Prescription-type opioid use disorder (POUD) is often accompanied by comorbid anxiety, yet the impact of anxiety on retention in opioid agonist therapy (OAT) is unclear. Therefore, this study investigated whether baseline anxiety severity affects retention in OAT and whether this effect differs by OAT type (methadone maintenance therapy (MMT) vs. buprenorphine/naloxone (BNX)).

METHODS

This secondary analysis used data from a pan-Canadian randomized trial comparing flexible take-home dosing BNX and standard supervised MMT for 24 weeks. The study included 268 adults with POUD. Baseline anxiety was assessed using the Beck Anxiety Inventory (BAI), with BAI ≥ 16 indicating moderate-to-severe anxiety. The primary outcomes were retention in assigned and any OAT at week 24. In addition, the impact of anxiety severity on retention was examined, and assigned OAT was considered an effect modifier.

RESULTS

Of the participants, 176 (65%) reported moderate-to-severe baseline anxiety. In adjusted analyses, there was no significant difference in retention between those with BAI ≥ 16 and those with BAI < 16 assigned (29% vs. 28%; odds ratio (OR) = 2.03, 95% confidence interval (CI) = 0.94-4.40; P = 0.07) or any OAT (35% vs. 34%; OR = 1.57, 95% CI = 0.77-3.21; P = 0.21). In addition, there was no significant effect modification by OAT type for retention in assigned (P = 0.41) or any OAT (P = 0.71). In adjusted analyses, greater retention in treatment was associated with BNX (vs. MMT), male gender identity (vs. female, transgender, or other), enrolment in the Quebec study site (vs. other sites), and absence of a positive urine drug screen for stimulants at baseline.

CONCLUSIONS

Baseline anxiety severity did not significantly impact retention in OAT for adults with POUD, and there was no significant effect modification by OAT type. However, the overall retention rates were low, highlighting the need to develop new strategies to minimize the risk of attrition from treatment.

CLINICAL TRIAL REGISTRATION

This study was registered in ClinicalTrials.gov (NCT03033732).

Contextual Factors and Adoption of Strategies Related to Opioid Prescribing Practices in Healthcare Settings: Cross-Sectional Study

This study aimed to examine the association between different contextual factors (e.g., facility size, rurality, and perceived needs) and the adoption of a policy or strategy related to opioid prescribing practices in healthcare settings. Cross-sectional survey data was collected from a convenience sample of physicians (N = 68). Logistic regression models were used to examine the effects of contextual factors on the dependent variables. Less than half reported having a policy restricting opioid prescribing practices, and 81% reported having one or more strategies for the safe use of chronic opioid therapy. After adjusting for other contextual factors, small practice size was positively associated with having a policy restricting opioid prescribing practices. This exploratory study provides insights for further investigation of how various contextual factors can influence policy adoption in different healthcare settings and practices to address major public health threats.

Grit and postoperative opioid use after total joint arthroplasty

INTRODUCTION

Perioperative multimodal protocols following total joint replacements have significantly decreased the amount of perioperative and postoperative opioids. Further identification of those requiring more or less opioids through individualisation, may further aid in reducing the amount prescribed. Therefore, the purpose of the study was to evaluate whether a patient's grit, the measurable psychological strength of character to persevere during hardship, measured by postoperative opioid consumption.

METHODS

Consecutive patients who had undergone either primary or revision total knee arthroplasty (TKA) or total hip arthroplasty (THA) from February 2019 to August 2020 at our institution logged their opioid use for the first 2 weeks postoperatively, detailing the type, dosage, and number of narcotics they consumed. Those who completed their logs and a grit questionnaire had their average morphine equivalent dose (MED) and grit score calculated. Analysis was then performed to evaluate if any association existed between these 2 variables.

RESULTS

There was no correlation between grit score and postoperative opioid consumption in the first 2 weeks following discharge after total joint arthroplasty. A total of 144 patients were eligible to participate and a total of 86 patients met inclusion criteria, 48 patients in the TKA group and 38 in the THA group. Of all patients, 63% were male. The average MED was 95.5 for THAs and 192 for TKAs. The average grit score was 4.23 for THAs and 4.19 for TKAs.

CONCLUSIONS

There is not an apparent association between grit score and postoperative opioid consumption in the first 2 weeks after total joint arthroplasty. General psychological resiliency may not be an important predictor of postoperative opioid use with modern postoperative protocols.

Pharmacokinetics of hydrorphone hydrochloride after intravenous and subcutaneous administration in ferrets (Mustela putorius furo)

OBJECTIVE

To determine the pharmacokinetic profile of hydromorphone 0.2 mg kg-1 administered by the intravenous (IV) and subcutaneous (SC) route in ferrets.

STUDY DESIGN

Randomized, crossover study.

ANIMALS

A group of eight adult ferrets weighting (mean ± standard deviation) 1.02 ± 0.22 kg.

METHODS

Hydromorphone hydrochloride 0.2 mg kg-1 was administered IV or SC with a washout period of 7 days. Blood samples were collected from a jugular catheter before administration of hydromorphone and at 5, 10, 15, 20, 30, 45, 60, 90, 120, 240, 360, 480 and 720 minutes after hydromorphone administration. Plasma hydromorphone concentrations were determined by liquid chromatography/tandem mass spectrometry. Data were analyzed using a non-linear mixed effects model.

RESULTS

The hydromorphone effective half-life was (t1/2) 45 min-1. Systemic clearance (Cls) and the volume of distribution (Vdss) following IV administration were 84.8 mL kg-1 min-1 and 5.59 L kg-1, respectively. The maximum observed plasma concentration was 59.53 ± 14.02 ng mL-1 within 10 minutes following SC administration. The SC bioavailability was 102.0%.

CONCLUSIONS AND CLINICAL RELEVANCE

Administration of IV and SC hydromorphone (0.2 mg kg-1) was characterized by a high clearance, short terminal half-life and large volume of distribution. Hydromorphone plasma concentrations remained greater than 2 ng mL-1 for 2 hours in most ferrets, a threshold reported to provide antinociceptive effects in other species. Hydromorphone was well absorbed following SC injection, providing an alternative administration route for clinical use in ferrets.

The Drivers of Persistent Opioid Use and Its Impact on Healthcare Utilization After Elective Spine Surgery

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim of this study was to determine the incidence of and risk factors for persistent opioid use after elective cervical and lumbar spine procedures and to quantify postoperative healthcare utilization in this patient population.

METHODS

Patients were retrospectively identified who underwent elective spine surgery for either cervical or lumbar degenerative pathology between November 1, 2013, and September 30, 2018, at a single academic center. Patients were split into 2 cohorts, including patients with and without opioid use at 180-days postoperatively. Baseline patient demographics, underlying comorbidities, surgical variables, and preoperative/postoperative opioid use were assessed. Health resource utilization metrics within 1 year postoperatively (ie, imaging studies, emergency and urgent care visits, hospital readmissions, opioid prescriptions, etc.) were compared between these 2 groups.

RESULTS

583 patients met inclusion criteria, of which 16.6% had opioid persistence after surgery. Opioid persistence was associated with ASA score ≥3 (P = .004), diabetes (P = .019), class I obesity (P = .012), and an opioid prescription in the 60 days prior to surgery (P = .006). Independent risk factors for opioid persistence assessed via multivariate regression included multi-level lumbar fusion (RR = 2.957), cervical central stenosis (RR = 2.761), and pre-operative opioid use (RR = 2.668). Opioid persistence was associated with higher rates of health care utilization, including more radiographs (P < .001), computed tomography (CT) scans (.007), magnetic resonance imaging (MRI) studies (P = .014), emergency department (ED) visits (.009), pain medicine referrals (P < .001), and spinal injections (P = .003).

CONCLUSIONS

Opioid persistence is associated with higher rates of health care utilization within 1 year after elective spine surgery.

Influences of Software Changes on Oxycodone Prescribing at an Australian Tertiary Emergency Department: A Retrospective Review

Opioid prescribing and dispensing from emergency departments is a noteworthy issue given widespread opioid misuse and diversion in many countries, contributing both physical and economic harm to the population. High patient numbers and the stochastic nature of acute emergency presentations to emergency departments (EDs) introduce challenges for prescribers who are considering opioid stewardship principles. This study investigated the effect of changes to electronic prescribing software on prescriptions with an auto-populated quantity of oxycodone immediate release (IR) from an Australian tertiary emergency department following the implementation of national recommendations for reduced pack sizes. A retrospective review of oxycodone IR prescriptions over two six-month periods between 2019 and 2021 was undertaken, either side of a software adjustment to reduce the default quantities of tablets prescribed from 20 to 10. Patient demographic details were collected, and prescriber years of practice calculated for inclusion in linear mixed effects regression modelling. A reduction in the median number of tablets prescribed per prescription following the software changes (13.5 to 10.0, p < 0.001) with little change in the underlying characteristics of the patient or prescriber populations was observed, as well as an 11.65% reduction in the total number of tablets prescribed. The prescriber's years of practice, patient age and patient sex were found to influence increased prescription sizes. Reduced quantity of oxycodone tablets prescribed was achieved by alteration of prescribing software prefill parameters, providing further evidence to support systems-based policy interventions to influence health care providers behaviour and to act as a forcing function for prescribers to consider opioid stewardship principles.

The impact of timing, type, and method of instillation of intraperitoneal local anaesthetic in laparoscopic abdominal surgery: a systematic review and network meta-analysis

BACKGROUND

Pain is common after laparoscopic abdominal surgery. Intraperitoneal local anaesthetic (IPLA) is effective in reducing pain and opioid use after laparoscopic surgery, although the optimum type, timing, and method of administration remains uncertain. We aimed to determine the optimal approach for delivering IPLA which minimises opioid consumption and pain after laparoscopic abdominal surgery.

METHODS

MEDLINE, Embase, Scopus, and Cochrane Central Register of Controlled Trials (CENTRAL) databases were systematically searched for randomised controlled trials comparing different combinations of the type (bupivacaine vs lidocaine vs levobupivacaine vs ropivacaine), timing (pre-vs post-pneumoperitoneum at the beginning or end of surgery), and method (aerosol vs liquid) of IPLA instillation in patients undergoing any laparoscopic abdominal surgery. A network meta-analysis was conducted to ascertain the optimum approach for delivering IPLA resulting in the least cumulative opioid consumption and pain (overall and localising to the shoulder) 24 h after surgery. Certainty of evidence was evaluated using Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) assessments (PROSPERO ID: CRD42022307595).

RESULTS

Twenty-five RCTs were included, among which 15 different combinations of delivering IPLA were analysed across 2401 participants. Aerosolised bupivacaine instilled at the end of surgery, before deflation of the pneumoperitoneum, was associated with significantly less postoperative opioid consumption compared with all other approaches for delivering IPLA (98.7% of comparisons; moderate certainty), aside from liquid levobupivacaine instilled before surgery and during or after creation of the pneumoperitoneum (mean difference -11.6, 95% credible interval: -26.1 to 2.5 i.v. morphine equivalent doses). There were no significant differences between different IPLA approaches regarding overall pain scores and incidence of shoulder pain up to 24 h after surgery.

CONCLUSIONS

There are limited studies and low-quality evidence to conclude on the optimum method of delivering IPLA in laparoscopic abdominal surgery. While aerosolised bupivacaine instilled at the end of surgery but before deflation of the pneumoperitoneum minimises postoperative opioid consumption, pain scores up to 24 h did not differ between the different modalities of delivering IPLA. The generalisability of these results is limited by the lack of utilisation of non-opioid analgesics in most trials.

SYSTEMATIC REVIEW PROTOCOL REGISTRATION

PROSPERO CRD42022307595.

Analgesia Administration by Sex Among Pediatric Emergency Department Patients with Abdominal Pain

Background

There is conflicting data about sex-based differences in the treatment of acute pain in the ED. Little is known about sex-based disparities in analgesia in pediatric ED patients.

Objectives

Our objective was to determine whether analgesic administration rates differ between female and male pediatric patients presenting to the ED with abdominal pain.

Methods

We conducted a retrospective cohort study of ED patients 5-21 years old with abdominal pain between 6/1/19 and 6/30/21. The primary outcome was receipt of any analgesia, and secondary outcomes were receipt of opioid analgesia and time to receipt of analgesia. Multivariable regression models were fitted for each outcome.

Results

We studied 1,087 patients; 681 (63%) were female with a median age of 17 years (IQR 13, 19) and 406 (37%) were male with a median age of 14 years (IQR 9, 18). 371 female patients (55%) and 180 male patients (44%) received any analgesia. 132 female patients (19%) and 83 male patients (20%) received opioid analgesia. In multivariate analyses, female patients were equally likely to receive any analgesia (OR 1.30, 95% CI 0.97 - 1.74, p = 0.07), but time to analgesia was 14% longer (GMR 1.14, 95% CI 1.00 - 1.29, p = 0.04). Non-White patients were 32% less likely to receive opioids (OR 0.68, 95% CI 0.47 - 0.97, p = 0.04).

Conclusions

Female pediatric ED patients were equally likely to receive any analgesia as male patients, but their time to analgesia was longer. Non-White patients were less likely to receive opioid analgesia than White patients.

Retrolaminar block for opioid-free anaesthesia and enhanced recovery after posterior lumbar discectomy: A randomised controlled study

Background and Aims

Intraoperative regional analgesia and enhanced recovery are standard care models aimed at reducing perioperative opioid use following spine surgeries. This study aimed to examine the analgesic effect of retrolaminar block in promoting recovery and pain relief after posterior lumbar discectomy.

Methods

The patients undergoing elective posterior lumbar discectomy were randomised into the retrolaminar group (n = 36) (received an intra-operative bilateral retrolaminar block with 15 mL of bupivacaine 0.25%, 2 mL (8 mg) of dexamethasone, and 2 mL of magnesium sulphate 10% (200 mg) on each side) and control group (n = 36) (received standard general anaesthesia). Primary outcomes were recovery time (time from isoflurane discontinuation to the first response to verbal command) and time to discharge (time from admission to the post-anaesthesia care unit (PACU) to discharge from the PACU, when Aldrete score was ≥9). P values < 0.05 were considered statistically significant.

Results

The extubation, recovery, and discharge times were significantly shorter in the retrolaminar group compared to the control group (P < 0.001). Postoperative pain scores were significantly lower in the retrolaminar group for up to 8 h compared to only 2 h in the control group (P < 0.001). The time to first administration of ketorolac post-operatively was significantly longer in the retrolaminar group compared to the control group (P < 0.001). The total consumption of ketorolac post-operatively was significantly reduced in the retrolaminar group compared to the control group (P < 0.001).

Conclusion

Intra-operative retrolaminar block is an easy and effective opioid-free regional anaesthesia technique that improves recovery after posterior lumbar discectomy.

Substance Use and Anxiety About Pain Among Patients Seeking Abortion Services

OBJECTIVES

To evaluate how recent opioid, marijuana, and cannabidiol use affects pre-procedure pain-related anxiety for patients seeking abortion.

METHODS

We conducted a prospective, cross-sectional anonymous survey of patients seeking abortion assessing recent substance use and anxiety about pain during and after abortion. We compared substance users' and non-users' anxiety scores.

RESULTS

Among 217 participants, recent opioid users (5.3%) had higher median anxiety scores for pain during (7.0 vs 6.0; p=0.33) and after (8.0 vs 6.0; p=0.01) abortion than non-opioid users. Anxiety scores were similar for marijuana and cannabidiol users.

CONCLUSIONS

Assessing recent opioid use may help guide counseling for anxiety about abortion.

Nitric oxide and potassium channels but not opioid and cannabinoid receptors mediate tramadol-induced peripheral antinociception in rat model of paw pressure withdrawal

Tramadol, an analgesic classified as an "atypical opioid", exhibits both opioid and non-opioid mechanisms of action. This study aimed to explore these mechanisms, specifically the opioid-, cannabinoid-, nitric oxide-, and potassium channel-based mechanisms, which contribute to the peripheral antinociception effect of tramadol, in an experimental rat model. The nociceptive threshold was determined using paw pressure withdrawal. To examine the mechanisms of action, several substances were administered intraplantarly: naloxone, a non-selective opioid antagonist (50 µg/paw); AM251 (80 µg/paw) and AM630 (100 µg/paw) as the selective antagonists for types 1 and 2 cannabinoid receptors, respectively; nitric oxide synthase inhibitors L-NOArg, L-NIO, L-NPA, and L-NIL (24 µg/paw); and the enzyme inhibitors of guanylatocyclase and phosphodiesterase of cGMP, ODQ, and zaprinast. Additionally, potassium channel blockers glibenclamide, tetraethylammonium, dequalinium, and paxillin were used. The results showed that opioid and cannabinoid receptor antagonists did not reverse tramadol's effects. L-NOarg, L-NIO, and L-NPA partially reversed antinociception, while ODQ completely reversed, and zaprinast enhanced tramadol's antinociception effect. Notably, glibenclamide blocked tramadol's antinociception in a dose-dependent manner. These findings suggest that tramadol's peripheral antinociception effect is likely mediated by the nitrergic pathway and sensitive ATP potassium channels, rather than the opioid and cannabinoid pathways.

Self-Reported Prescription Opioid Use Among Participants with Chronic Spinal Cord Injury

Background

Individuals with spinal cord injuries (SCI) experience high rates of prescription opioid use, yet there is limited data on frequency of opioid use and specific medications being taken.

Objectives

To examine the frequency of self-reported prescription opioid use among participants with SCI and the relationship with demographic, injury, and socioeconomic characteristics.

Methods

A cohort study of 918 adults with SCI of at least 1-year duration completed a self-report assessment (SRA) that indicated frequency of specific prescription opioid use based on the National Survey on Drug Use and Health (NSDUH).

Results

Forty-seven percent of the participants used at least one prescription opioid over the last year; the most frequently used was hydrocodone (22.1%). Nearly 30% used a minimum of one opioid at least weekly. Lower odds of use of at least one opioid over the past year was observed for Veterans (odds ratio [OR] = 0.60, 95% CI = 0.38, 0.96) and those with a bachelor's degree or higher (OR = 0.63, 95% CI = 0.44, 0.91). When restricting the analysis to use of at least one substance daily or weekly, lower odds of use was observed for those with a bachelor's degree or higher and those with income ranging from $25,000 to $75,000+. None of the demographic or SCI variables were significantly related to prescription opioid use.

Conclusion

Despite the widely established risks, prescription opioids were used daily or weekly by more than 28% of the participants. Usage was only related to Veteran status and socioeconomic status indicators, which were protective of use. Alternative treatments are needed for those with the heaviest, most regular usage.

The Finnegan Score for Neonatal Opioid Withdrawal Revisited With Routine Electronic Data: Retrospective Study

Background

The severity of neonatal abstinence syndrome (NAS) may be assessed with the Finnegan score (FS). Since the FS is laborious and subjective, alternative ways of assessment may improve quality of care.

Objective

In this pilot study, we examined associations between the FS and routine monitoring data obtained from the electronic health record system.

Methods

The study included 205 neonates with NAS after intrauterine (n=23) or postnatal opioid exposure (n=182). Routine monitoring data were analyzed at 60±10 minutes (t-1) and 120±10 minutes (t-2) before each FS assessment. Within each time period, the mean for each variable was calculated. Readings were also normalized to individual baseline data for each patient and parameter. Mixed effects models were used to assess the effect of different variables.

Results

Plots of vital parameters against the FS showed heavily scattered data. When controlling for several variables, the best-performing mixed effects model displayed significant effects of individual baseline-controlled mean heart rate (estimate 0.04, 95% CI 0.02-0.07) and arterial blood pressure (estimate 0.05, 95% CI 0.01-0.08) at t-1 with a goodness of fit (R2m) of 0.11.

Conclusions

Routine electronic data can be extracted and analyzed for their correlation with FS data. Mixed effects models show small but significant effects after normalizing vital parameters to individual baselines.

Epidemiological Aspects of Opioid Poisoning in Northern Iran: A Registry-Based Clinical Study

Opioids are a class of drugs that are commonly used to manage pain due to their analgesic and sedative effects. However, the high consumption of opioids in the community has led to an increase in the incidence of overdoses and poisonings caused by various types of these drugs, whether intentional or unintentional. Therefore, comprehending the epidemiological features of patients experiencing opioid poisoning is crucial. We decided to investigate various epidemiological aspects of patients with opioid poisoning in the Mazandaran province, located in northern Iran, during the period of 2020 to 2021. The present investigation was conducted as a descriptive cross-sectional study, wherein we collected data on patients registered in the Mazandaran Registry Center of Opioid Poisoning (MRCOP) who had a history of using any kind of opioid. We collected information on various parameters, including patient demographics, the type of opioid consumed, the mode of consumption, and clinical outcomes. A total of 240 patients were initially registered at the registry center. However, 17 cases were excluded with personal consent, and eventually, a total of 223 patients were included in the investigation. The majority of the patients 70.9% (n = 158) were male, and the average age was 34.4 ± 16.55 years. The most common cause of poisoning reported in our study was intentional, which was mainly due to a suicide attempt. Furthermore, the most prevalent type of opioid consumed was methadone. The most frequently observed symptoms of poisoning among the patients were drowsiness, a decreased level of consciousness, and reduced arterial oxygen saturation levels. Based on the results of our study, several factors were found to be significant in methadone poisoning, including addiction, age, gender, suicide attempt, and a history of psychiatric disorder. These findings highlight the need for public education and awareness campaigns on the risks associated with opioid use, particularly methadone.

Impact of the Narcotics Information Management System on Opioid Use Among Outpatients With Musculoskeletal and Connective Tissue Disorders: Quasi-Experimental Study Using Interrupted Time Series

BACKGROUND

Opioids have traditionally been used to manage acute or terminal pain. However, their prolonged use has the potential for abuse, misuse, and addiction. South Korea introduced a new health care IT system named the Narcotics Information Management System (NIMS) with the objective of managing all aspects of opioid use, including manufacturing, distribution, sales, disposal, etc.

OBJECTIVE

This study aimed to assess the impact of NIMS on opioid use.

METHODS

We conducted an analysis using national claims data from 45,582 patients diagnosed with musculoskeletal and connective tissue disorders between 2016 and 2020. Our approach included using an interrupted time-series analysis and constructing segmented regression models. Within these models, we considered the primary intervention to be the implementation of NIMS, while we treated the COVID-19 outbreak as the secondary event. To comprehensively assess inappropriate opioid use, we examined 4 key indicators, as established in previous studies: (1) the proportion of patients on high-dose opioid treatment, (2) the proportion of patients receiving opioid prescriptions from multiple providers, (3) the overlap rate of opioid prescriptions per patient, and (4) the naloxone use rate among opioid users.

RESULTS

During the study period, there was a general trend of increasing opioid use. After the implementation of NIMS, significant increases were observed in the trend of the proportion of patients on high-dose opioid treatment (coefficient=0.0271; P=.01) and in the level of the proportion of patients receiving opioid prescriptions from multiple providers (coefficient=0.6252; P=.004). An abrupt decline was seen in the level of the naloxone use rate among opioid users (coefficient=-0.2968; P=.04). While these changes were statistically significant, their clinical significance appears to be minor. No significant changes were observed after both the implementation of NIMS and the COVID-19 outbreak.

CONCLUSIONS

This study suggests that, in its current form, the NIMS may not have brought significant improvements to the identified indicators of opioid overuse and misuse. Additionally, the COVID-19 outbreak exhibited no significant influence on opioid use patterns. The absence of real-time monitoring feature within the NIMS could be a key contributing factor. Further exploration and enhancements are needed to maximize the NIMS' impact on curbing inappropriate opioid use.

Are carfentanil and acrylfentanyl naloxone resistant?

The rapid rise in deaths since 2012 due to opioid poisoning is correlated with the proliferation of potent synthetic opioid agonists such as fentanyl, acrylfentanyl, and carfentanil. The efficacy of frontline antidotes such as naloxone in reversing such poisoning events has been questioned, and the possibility of naloxone-resistant synthetic opioids has been raised. In this manuscript, we applied in vitro techniques to establish the median effective inhibitory concentrations for fentanyl, acrylfentanyl, and carfentanil and subsequently evaluate naloxone's ability to reverse agonist-receptor interactions.

Effect of Best Practice Alert (BPA) on Post-Discharge Opioid Prescribing After Minimally Invasive Hysterectomy: A Quality Improvement Study

Purpose

The aim of this study was to describe the effectiveness of an electronic health record best practice alert (BPA) in decreasing gynecologic post-discharge opioid prescribing following benign minimally invasive hysterectomy.

Patients and Methods

The BPA triggered for opioid orders >15 tablets. Prescribers' options included (1) decrease to 15 ≤ tablets; (2) remove the order/utilize a defaulted order set; or (3) override the alert.

Results

332 patients were included. The BPA triggered 29 times. The following actions were taken among 16 patients for whom the BPA triggered: "override the alert" (n=13); "cancel the alert" (n=2); and 'remove the opioid order set' (n=1). 12/16 patients had discharge prescriptions: one patient received 20 tablets; two received 10 tablets; and nine received 15 tablets. Top reasons for over prescribing included concerns for pain control and lack of alternatives.

Conclusion

Implementing a post-discharge opioid prescribing BPA aligned opioid prescribing following benign minimally invasive hysterectomy with guideline recommendations.

A Balancing Act: Learning from the Past to Build a Future-Focused Opioid Strategy

The harmful side effects of opioid drugs such as respiratory depression, tolerance, dependence, and abuse potential have limited the therapeutic utility of opioids for their entire clinical history. However, no previous attempt to develop effective pain drugs that substantially ameliorate these effects has succeeded, and the current opioid epidemic affirms that they are a greater hindrance to the field of pain management than ever. Recent attempts at new opioid development have sought to reduce these side effects by minimizing engagement of the regulatory protein arrestin-3 at the mu-opioid receptor, but there is significant controversy around this approach. Here, we discuss the ongoing effort to develop safer opioids and its relevant historical context. We propose a new model that reconciles results previously assumed to be in direct conflict to explain how different signaling profiles at the mu-opioid receptor contribute to opioid tolerance and dependence. Our goal is for this framework to inform the search for a new generation of lower liability opioid analgesics.

Qualitative Evaluation Informs the Implementation of a Telehealth Program to Manage Chronic Pain

In response to the opioid epidemic and high rates of chronic pain among the veteran population, the U.S. Department of Veterans Affairs implemented the TelePain-Empower Veterans Program (EVP), a nonpharmacological pain management program for veterans. Delivered virtually, TelePain-EVP incorporates integrated health components (Whole Health, Acceptance and Commitment Therapy, and Mindful Movement) through interdisciplinary personalized coaching. The objective of this quality improvement project was to evaluate the implementation of TelePain-EVP to identify determinants to implementation, benefits and challenges to participation, and recommendations for future direction. We used a qualitative descriptive design to conduct semistructured telephone interviews with TelePain-EVP leaders (n = 3), staff (n = 10), and veterans (n = 22). The interview guides aligned with the Consolidated Framework for Implementation Research (CFIR). Thematic content analysis organized and characterized findings. Several CFIR domains emerged as determinants relevant to program implementation, including innovation (eg, design); individuals (eg, deliverers, recipients); inner (eg, communications) and outer settings (eg, local conditions); and implementation process (eg, reflecting and evaluating). Identified determinants included facilitators (eg, virtual delivery) and barriers (eg, staff shortages). Participants reported improvements in pain management coping skills, interpersonal relationships, and sense of community, but no self-reported reductions in pain or medication use. Program improvement recommendations included using centralized staff to address vacancies, collecting electronic data, offering structured training, and providing course materials to veteran participants. Qualitative data can inform the sustained implementation of TelePain-EVP and other similar telehealth pain management programs. These descriptive data should be triangulated with quantitative data to objectively assess participant TelePain-EVP outcomes and associated participant characteristics. PERSPECTIVE: A qualitative evaluation of a telehealth program to manage chronic pain, guided by the CFIR framework, identified determinants of program implementation. Additionally, participants reported improvements in pain management coping skills, interpersonal relationships, and sense of community, but no self-reported reductions in pain or medication use.

Opioid-Induced Hyperalgesia and Tolerance Are Driven by HCN Ion Channels

Prolonged exposure to opioids causes an enhanced sensitivity to painful stimuli (opioid-induced hyperalgesia, OIH) and a need for increased opioid doses to maintain analgesia (opioid-induced tolerance, OIT), but the mechanisms underlying both processes remain obscure. We found that pharmacological block or genetic deletion of HCN2 ion channels in primary nociceptive neurons of male mice completely abolished OIH but had no effect on OIT. Conversely, pharmacological inhibition of central HCN channels alleviated OIT but had no effect on OIH. Expression of C-FOS, a marker of neuronal activity, was increased in second-order neurons of the dorsal spinal cord by induction of OIH, and the increase was prevented by peripheral block or genetic deletion of HCN2, but block of OIT by spinal block of HCN channels had no impact on C-FOS expression in dorsal horn neurons. Collectively, these observations show that OIH is driven by HCN2 ion channels in peripheral nociceptors, while OIT is driven by a member of the HCN family located in the CNS. Induction of OIH increased cAMP in nociceptive neurons, and a consequent shift in the activation curve of HCN2 caused an increase in nociceptor firing. The shift in HCN2 was caused by expression of a constitutively active μ-opioid receptor (MOR) and was reversed by MOR antagonists. We identified the opioid-induced MOR as a six-transmembrane splice variant, and we show that it increases cAMP by coupling constitutively to Gs HCN2 ion channels therefore drive OIH, and likely OIT, and may be a novel therapeutic target for the treatment of addiction.

Opioid Utilization After Primary Total Hip and Knee Arthroplasty Following Sequential Implementation of Statewide Legislation

Background

Following total hip arthroplasty (THA) and total knee arthroplasty (TKA), increased opioid use is associated with poor clinical outcomes. This study investigates implications of Florida legislative mandates on prescribing practices and opioid utilization following primary THA and TKA.

Methods

We retrospectively reviewed patients undergoing primary TKA or THA between January 1, 2018, to December 31, 2020 at our academic medical center. Three groups were identified: procedures performed prior to mandates, after seven-day prescription limit, and after mandated electronic prescribing. A multivariate analyses of variance evaluated length of stay, morphine milligram equivalents (MMEs), age, body mass index and number of prescription refills. Chi-square tests compared preoperative opioid use, readmissions, and discharge disposition.

Results

There were 198 patients in group one, 238 patients in group two, and 215 patients in group three (N = 651). Prior to any mandates, patients were prescribed 822.3 + 626.7 MMEs. Following a seven-day prescription limit this decreased to 465.0 + 296.0 MMEs (P < .001), which further decreased after mandated electronic prescribing (228.0 + 284.4 MMEs [P < 0.001]). Patients undergoing THA were prescribed less MME than those undergoing TKA. There was a 2.6% 90-day readmission rate, with no pain-related readmissions.

Conclusions

Florida legislative mandates for opioid prescription quantities and electronic prescribing have effectively reduced average MMEs prescribed following primary arthroplasty. Despite a shift towards ambulatory surgery, opioid utilization decreased without compromising patient outcomes. These findings underscore the significance of both legislative and surgical practices influencing opioid prescribing habits among orthopaedic surgeons.

Methadone Withdrawal-Induced Psychosis: A Case Report

Methadone is a synthetic full µ-opioid receptor agonist and N-methyl-D-aspartate antagonist given to patients who have recently stopped using illicit opioids or are tapering off chronic opioid pain medication. Maintenance treatment with methadone is today the most widespread and effective way to treat opiate addiction, which achieves abstinence, decreases morbidity and mortality, improves quality of life, and reduces crime genesis, among other benefits. It is also approved by the Food and Drug Administration for treating moderate-to-severe pain that remains unresponsive to nonopioid medications. Patients sometimes abruptly discontinue the medication for several reasons and sometimes suffer distressing but non-life-threatening withdrawal symptoms. More common withdrawal symptoms include anxiety, agitation, rhinorrhea, nausea, and vomiting, like other opioid agonist medications. Psychosis has been reported in some rare cases of methadone withdrawal. However, more research is required because, although psychotic symptoms have been described in different case reports after the reduction or withdrawal of methadone, they have not been sufficient. This case report contributes to the literature on rare manifestations of psychosis in patients who abruptly discontinue the use of methadone.

Iliac Crest Bone Graft Harvest for Alveolar Cleft Repair: A Systematic Review Comparing Minimally Invasive Trephine and Conventional Open Techniques

Background: In the course of developing a standardized pathway for alveolar cleft repair, we conducted a systematic review comparing minimally invasive trephine with conventional open technique for iliac crest bone graft harvest in a pediatric population. Methods: A systematic review was conducted of studies comparing open with minimally invasive trephine techniques in pediatric populations undergoing alveolar cleft repair. Exclusion criteria included reviews, case series, editorials, abstracts, and those with adult-only populations. Data were compiled with outcome variables selected a priori. Results: Of 422 manuscripts screened, five met criteria. These comprised 257 patients (116 open, 141 trephine). Average age was 11 years. Patients undergoing trephine harvest had reduced length of stay (1.0-5.0 days trephine vs 1.25-5.4 days open), time to unassisted ambulation (16-46 hours vs 20-67 hours open), and less postoperative narcotic use (0.31 mg/kg vs 1.64 mg/kg IV morphine). Volume of cancellous bone was reported as 2.53 mL for open versus 1.22 mL for trephine in one study, and trephine graft was supplemented with demineralized bone in 54% of cases in another study. The use of anesthetic adjuncts was inconsistent but had a significant effect on postoperative pain and ambulation. Conclusions: Compared to open techniques, the minimally invasive trephine bone graft harvest is associated with a shorter time to discharge, slightly lower infection rates, and reduced opioid use. The possible benefits of trephine harvest must however be balanced against the risk of insufficient graft harvest. Finally, the choice of perioperative analgesic adjuncts significantly impacts patient outcomes regardless of the technique employed.

Pain management for post-treatment survivors of complex cancers: a qualitative study of opioids and cannabis

Aim: We aimed to understand experiences with opioids and cannabis for post-treatment cancer survivors. Patients & methods: We conducted seven focus groups among head and neck and lung cancer survivors, using standard qualitative methodology to explore themes around 1) post-treatment pain and 2) utilization, perceived benefits and perceived harms of cannabis and opioids. Results & conclusion: Survivors (N = 25) experienced addiction fears, stigma and access challenges for both products. Opioids were often perceived as critical for severe pain. Cannabis reduced pain and anxiety for many survivors, suggesting that anxiety screening, as recommended in guidelines, would improve traditional pain assessment. Opioids and cannabis present complex harms and benefits for post-treatment survivors who must balance pain management and minimizing side effects.

Differences in adverse outcomes across race and ethnicity among Veterans with similar predicted risks of an overdose or suicide-related event

OBJECTIVE

To evaluate the degree to which differences in incidence of mortality and serious adverse events exist across patient race and ethnicity among Veterans Health Administration (VHA) patients receiving outpatient opioid prescriptions and who have similar predicted risks of adverse outcomes. Patients were assigned scores via the VHA Stratification Tool for Opioid Risk Mitigation (STORM), a model used to predict the risk of experiencing overdose- or suicide-related health care events or death. Individuals with the highest STORM risk scores are targeted for case review.

DESIGN

Retrospective cohort study of high-risk veterans who received an outpatient prescription opioid between 4/2018-3/2019.

SETTING

All VHA medical centers.

PARTICIPANTS

In total, 84 473 patients whose estimated risk scores were between 0.0420 and 0.0609, the risk scores associated with the top 5%-10% of risk in the STORM development sample.

METHODS

We examined the expected probability of mortality and serious adverse events (SAEs; overdose or suicide-related events) given a patient's risk score and race.

RESULTS

Given a similar risk score, Black patients were less likely than White patients to have a recorded SAE within 6 months of risk score calculation. Black, Hispanic, and Asian patients were less likely than White patients with similar risk scores to die within 6 months of risk score calculation. Some of the mortality differences were driven by age differences in the composition of racial and ethnic groups in our sample.

CONCLUSIONS

Our results suggest that relying on the STORM model to identify patients who may benefit from an interdisciplinary case review may identify patients with clinically meaningful differences in outcome risk across race and ethnicity.

Is there a relationship between opioid use and transient global amnesia?

BACKGROUND AND PURPOSE

Opioid-associated amnestic syndrome (OAS) and transient global amnesia (TGA) are conditions with clinical overlap. We therefore sought to determine whether opioid use might be associated with TGA.

METHODS

Data from the Massachusetts Department of Public Health Syndromic Surveillance program were queried to ascertain the frequency of opioid use among emergency department (ED) encounters for TGA compared to that for all other ED visits between January 2019 and June 2023.

RESULTS

A total of 13,188,630 ED visits were identified during the study period. Of 1417 visits for TGA, one visit met the exposure definition for opioid use. There were 13,187,213 visits for other indications, 57,638 of which were considered opioid-exposed. The odds ratio for the relationship between opioid use and TGA was 0.16 (95% confidence interval 0.02, 1.14).

CONCLUSION

Despite the clinical overlap between OAS and TGA, surveillance data from ED visits in Massachusetts do not suggest that opioid use is a risk factor for TGA, indicating that OAS and TGA are distinct entities.

Nonopioid Pain Management Pathways for Stone Disease

Introduction: New opioid dependency after urologic surgery is a serious adverse outcome that is well-described in the literature. Patients with stone disease often require multiple procedures because of recurrence of disease and hence are at greater risk for repeat opioid exposures. Despite this, opioid prescribing after urologic surgery remains highly variable and in an emergency setting, opioids are still used commonly in management of acute renal colic. Methods: Two literature searches were performed using PubMed. First, we searched available literature concerning opioid-sparing pathways in acute renal colic. Second, we searched available literature for opioid-sparing pathways in ureteroscopy and percutaneous nephrolithotomy (PCNL). Abstracts were reviewed for inclusion in our narrative review. Results: In the setting of acute renal colic, multiple randomized control trials have shown that nonsteroidal anti-inflammatory drugs (NSAIDs) attain greater reduction in pain scores, decreased need for rescue medications, and decreased vomiting events in comparison with opioids. NSAIDs also form a core component in management of postureteroscopy pain and have been demonstrated in randomized trials to have equivalent to improved pain control outcomes compared with opioids. Multiple opioid-free pathways have been described for postureteroscopy analgesia with need for rescue narcotics falling under 20% in most studies, including in patients with ureteral stents. Enhanced Recovery After Surgery protocols after percutaneous nephrolithotomy are less well described but have yielded a reduction in postoperative opioid requirements. Conclusions: In select patients, both acute renal colic and after kidney stone surgery, adequate pain management can usually be obtained with minimal or no opioid medication. NSAIDs form the core of most described opioid-sparing pathways for both ureteroscopy and PCNL, with the contribution of other components to postoperative pain outcomes limited because of lack of head-to-head comparisons. However, medications aimed specifically at targeting stent-related discomfort form a key component of most multimodal postsurgical pain management pathways. Further investigation is needed to develop pathways in patients unable to tolerate NSAIDs.

Comprehensive Approach to Opioid Management in a Primary Care Network

In response to the opioid epidemic, the Centers for Disease Control and Prevention released best practice recommendations for prescribing, yet adoption of these guidelines has been fragmented and frequently met with uncertainty by both patients and providers. This study aims to describe the development and implementation of a comprehensive approach to improving opioid stewardship in a large network of primary care providers. The authors developed a 3-tier approach to opioid management: (1) establishment and implementation of best practices for prescribing opioids, (2) development of a weaning process to decrease opioid doses when the risk outweighs benefits, and (3) support for patients when opioid use disorders were identified. Across 44 primary care practices caring for >223,000 patients, the total number of patients prescribed a chronic opioid decreased from 4848 patients in 2018 to 3106 patients in 2021, a decrease of 36% (P < 0.001). The percent of patients with a controlled substance agreement increased from 13% to 83% (P < 0.001) and the percent of patients completing an annual urine drug screen increased from 17% to 53% (P < 0.001). The number of patients coprescribed benzodiazepines decreased from 1261 patients at baseline to 834 at completion. A total of 6.5% of patients were referred for additional support from a certified alcohol and substance abuse counselor embedded within the program. Overall, the comprehensive opioid management program provided the necessary structure to support opioid prescribing and resulted in improved adherence to best practices, facilitated weaning of opioids when medically appropriate, and enhanced support for patients with opioid use disorders.

The dopamine 3 receptor as a candidate biomarker and therapeutic for opioid use disorder

Here, we present recent studies suggesting that specific DRD3 single nucleotide polymorphisms (SNPs, e.g. rs324029 and rs2654754) might serve as prognostic biomarkers for opioid use disorder (OUD). Additionally, preclinical studies with novel dopamine 3 receptor (D3R) partial agonists and antagonists have been evaluated as candidate OUD therapeutics and have shown a reduced risk of cardiovascular toxicity compared with the original D3R antagonist. From these findings, we argue that DRD3 SNPs could serve as a diagnostic tool for assessing OUD risk and that more research is warranted examining the D3R as a safe and effective therapeutic target for treating OUD.

Association between household opioid prescriptions and risk for overdose among family members not prescribed opioids

BACKGROUND

Prescription opioids have contributed to the rise in opioid-related overdoses and deaths. The presence of opioids within households may increase the risk of overdose among family members who were not prescribed an opioid themselves. Larger quantities of opioids may further increase risk.

OBJECTIVES

To determine the risk of opioid overdose among individuals who were not prescribed an opioid but were exposed to opioids prescribed to other family members in the household, and evaluate the risk in relation to the total morphine milligram equivalents (MMEs) present in the household.

METHODS

We conducted a cohort study using a large database of commercial insurance claims from 2001 to 2021. For inclusion in the cohort, we identified individuals not prescribed an opioid in the prior 90 days from households with two or more family members, and determined the total MMEs prescribed to other family members. Individuals were stratified into monthly enrollment strata defined by household opioid exposure and other confounders. A generalized linear model was used to estimate incidence rate ratios (IRRs) for overdose.

RESULTS

Overall, the incidence of overdose among enrollees in households where a family member was prescribed an opioid was 1.73 (95% confidence interval [CI]: 1.67-1.78) times greater than households without opioid prescriptions. The risk of overdose increased continuously with the level of potential MMEs in the household from an IRR of 1.23 (95% CI: 1.16-1.32) for 1-100 MMEs to 4.67 (95% CI: 4.18-5.22) for >12,000 MMEs. The risk of overdose associated with household opioid exposure was greatest for ages 1-2 years (IRR: 3.46 [95% CI: 2.98-4.01]) and 3-5 years (IRR: 3.31 [95% CI: 2.75-3.99]).

CONCLUSIONS

The presence of opioids in a household significantly increases the risk of overdose among other family members who were not prescribed an opioid. Higher levels of MMEs, either in terms of opioid strength or quantity, were associated with increased levels of risk. Risk estimates may reflect accidental poisonings among younger family members.

Opioid-related overdose deaths among people experiencing homelessness, 2017 to 2021: A population-based analysis using coroner and health administrative data from Ontario, Canada

AIMS

To measure the change in proportion of opioid-related overdose deaths attributed to people experiencing homelessness and to compare the opioid-related fatalities between individuals experiencing homelessness and not experiencing homelessness at time of death.

DESIGN, SETTING AND PARTICIPANTS

Population-based, time-trend analysis using coroner and health administrative databases from Ontario, Canada from 1 July 2017 and 30 June 2021.

MEASUREMENTS

Quarterly proportion of opioid-related overdose deaths attributed to people experiencing homelessness. We also obtained socio-demographic and health characteristics of decedents, health-care encounters preceding death, substances directly contributing to death and circumstances surrounding deaths.

FINDINGS

A total of 6644 individuals (median age = 40 years, interquartile range = 31-51; 74.1% male) experienced an accidental opioid-related overdose death, among whom 884 (13.3%) were identified as experiencing homelessness at the time of death. The quarterly proportion of opioid-related overdose deaths attributed to people experiencing homelessness increased from 7.2% (26/359) in July-September 2017 to 16.8% (97/578) by April-June 2021 (trend test P < 0.01). Compared with housed decedents, those experiencing homelessness were younger (61.3 versus 53.1% aged 25-44), had higher prevalence of mental health or substance use disorders (77.1 versus 67.1%) and more often visited hospitals (32.1 versus 24.5%) and emergency departments (82.6 versus 68.5%) in the year prior to death. Fentanyl and its analogues more often directly contributed to death among people experiencing homelessness (94.0 versus 81.4%), as did stimulants (67.4 versus 51.6%); in contrast, methadone was less often present (7.8 versus 12.4%). Individuals experiencing homelessness were more often in the presence of a bystander during the acute toxicity event that led to death (55.8 versus 49.7%); and where another individual was present, more often had a resuscitation attempted (61.7 versus 55.1%) or naloxone administered (41.2 versus 28.9%).

CONCLUSIONS

People experiencing homelessness account for an increasing proportion of fatal opioid-related overdoses in Ontario, Canada, reaching nearly one in six such deaths in 2021.

Role of α1-GABAA receptors in the serotonergic dorsal raphe nucleus in models of opioid reward, anxiety, and depression

BACKGROUND

The serotonin (5-hydroxytryptamine (5-HT))-mediated system plays an important role in stress-related psychiatric disorders and substance abuse. Our previous studies showed that stress and drug exposure can modulate the dorsal raphe nucleus (DRN)-5-HT system via γ-aminobutyric acid (GABA)A receptors. Moreover, GABAA receptor-mediated inhibition of serotonergic DRN neurons is required for stress-induced reinstatement of opioid seeking.

AIM/METHODS

To further test the role of GABAA receptors in the 5-HT system in stress and opioid-sensitive behaviors, our current study generated mice with conditional genetic deletions of the GABAA α1 subunit to manipulate GABAA receptors in either the DRN or the entire population of 5-HT neurons. The GABAA α1 subunit is a constituent of the most abundant GABAA subtype in the brain and the most highly expressed subunit in 5-HT DRN neurons.

RESULTS

Our results showed that mice with DRN-specific knockout of α1-GABAA receptors exhibited a normal phenotype in tests of anxiety- and depression-like behaviors as well as swim stress-induced reinstatement of morphine-conditioned place preference. By contrast, mice with 5-HT neuron-specific knockout of α1-GABAA receptors exhibited an anxiolytic phenotype at baseline and increased sensitivity to post-morphine withdrawal-induced anxiety.

CONCLUSIONS

Our data suggest that GABAA receptors on 5-HT neurons contribute to anxiety-like behaviors and sensitivity of those behaviors to opioid withdrawal.

Pain medication misuse in the South African spinal cord injury context

Background

Pain after spinal cord injury (SCI) is debilitating and has been reported to be difficult to treat, despite pharmacological interventions. Pain medication misuse (PMM) and associated individual factors among people with spinal cord injury (PWSCI) are scarce.

Aim

To determine PMM and the associated factors in PWSCI.

Setting

Homes of community-dwelling manual wheelchair users with SCI in South Africa.

Methods

Community-dwelling PWSCI (n = 122) were consecutively sampled and the Pain Medication Questionnaire (PMQ) was used to determine PMM. Descriptive statistics, Fisher's exact test, independent t-tests, and simple linear regression tests were performed using SPSS v27. Testing was conducted at the 0.05 level of significance.

Results

Eighty-five per cent of the participants reported the presence of pain and 48.1% of them used pain medication. Forty-four percent of people who used pain medication scored ≥ 30, indicative of serious aberrant drug-taking behaviours. Opioids were mainly used for neuropathic pain and in combination with other types of medications such as anticonvulsants and non-steroidal anti-inflammatories (44.0%). Pain severity and the type of pain medication were found to be predictors of PMM (p < 0.01 respectively).

Conclusion

Pain relief after SCI remains difficult to achieve, with an evident high risk of PMM, which may lead to long-lasting side effects, dependency, or overdose.

Contribution

This study has shown the need for the assessment of the potential risk of dependency before prescribing pain medication, particularly opioids to PWSCI.

Persistent Hiccups Shortly after Tramadol Intake: A Case Report and Literature Review

BACKGROUND AND OBJECTIVE

Tramadol can inhibit serotonin and norepinephrine reuptake leading to stimulation of the central component of the hiccup reflex arc. We have found only two previous cases of tramadol-induced hiccups. Additionally, three pharmacovigilance studies have investigated the involvement of tramadol in cases who have developed hiccups as adverse effects. Herein, we have presented a case of a middle-aged male who has developed hiccups shortly after tramadol intake.

CASE PRESENTATION

A 35-year-old male complaining of chronic pain in the right knee was treated with tramadol. The individual developed hiccups within 10 hours of the first tramadol dose. The patient tried to stop the hiccups with non-pharmacological measures, such as stopping the air inside the lungs and drinking cold fluids. The patient appeared to concentrate on avoiding hiccups, which he could avoid for some time. However, then, the hiccups would come all at a unique time. The hiccups occurred at a frequency of one hiccup/5-10 seconds, interrupting the patient's nutrition and sleep pattern. Eventually, tramadol was suspected of inducing hiccups, and baclofen was started.

CONCLUSION

Tramadol as well as opioids should be considered as a cause of hiccups. We aim to improve awareness about the safety of such drugs among physicians and the proper management of associated risks.

The Impact of Opioid Receptor Gene Polymorphism on Fentanyl and Alfentanil's Analgesic Effects in the Pediatric Perioperative Period

Introduction

The polymorphism of the gene coding mu-opioid receptor (OPRM1) is one of the factors contributing to the variability in the response to opioid analgesics in children. The goal of this study is to investigate its role in association with postoperative acute pain in children of various ages.

Methods

This prospective study analyzed 110 pediatric patients, after plastic or orthopedic surgery, who were genotyped and randomly assigned to receive fentanyl or alfentanil. Postoperative pain was rated using Numerical Rating Scale (0-10). All the patients were genotyped forOPRM1 118A>G (rs1799971) gene polymorphism.

Results

School children under the age of 11 with the OPRM1 AA genotype were shown to have a higher BMI (p<0.05). Children over the age of 12 carrying G allele OPRM1, had increased postoperative pain sensitivity and intensity (3.28±1.95 vs 4.91±2.17; p<0.05), as compared to AA allele carriers.

Discussion

OPRM1 118A>G polymorphism may explain the variation in the perception of postoperative pain in children over the age of 12 and may be a useful predictor for adjusting the dose of analgesics, but the dose is relative to the patient's needs regardless of his genetic characteristics. In younger children, carriers of polymorphic OPRM1 118G allele may be protected from obesity, due to diminished MOP expression.

Low-dose Initiation of Buprenorphine/naloxone for the Management of Chronic Non-cancer Pain in Patients on Long-term Opioid Therapy: A Case Series

Background

Buprenorphine may provide superior analgesia to full opioid agonist therapy and reverse the effects of opioid-induced hyperalgesia, while having a favorable safety profile and fewer adverse effects, in chronic non-cancer pain treatment. Low-dose initiation of buprenorphine is a useful strategy for patients on long-term opioid therapy because it avoids the need for moderate opioid withdrawal required for traditional buprenorphine initiations. However, there are few published reports of low-dose initiation regimens in the setting of chronic pain.

Aims

The aim of the study was to describe a case series of individuals living with chronic pain who were transitioned from long-term full opioid agonist therapy onto sublingual buprenorphine/naloxone using low-dose initiation regimens.

Methods

This study is a retrospective case series that included all patients who received care at an outpatient chronic pain clinic and were scheduled for low-dose initiation of buprenorphine/naloxone between March 2020 and December 2022. Data were collected through a retrospective review of electronic medical records and results were analyzed using descriptive statistics.

Results

Eighteen patients underwent transitions from their baseline opioids onto buprenorphine/naloxone using a low-dose initiation regimen. Of those patients, 17 successfully completed the initiation (94.44%), 12 experienced adverse effects during the initiation (66.67%), with only one patient requiring treatment discontinuation, and all adverse effects resolved once maintenance doses of buprenorphine/naloxone were established. The mean Clinical Global Impression-Improvement score after initiation was 2 (1-5).

Conclusion

Low-dose initiation is an effective approach to transition patients with chronic non-cancer pain from long-term opioid therapy to buprenorphine/naloxone without major complications or worsening pain.

Opioidergic signaling contributes to food-mediated suppression of AgRP neurons

Opioids are generally known to promote hedonic food consumption. Although much of the existing evidence is primarily based on studies of the mesolimbic pathway, endogenous opioids and their receptors are widely expressed in hypothalamic appetite circuits as well; however, their role in homeostatic feeding remains unclear. Using a fluorescent opioid sensor, deltaLight, here we report that mediobasal hypothalamic opioid levels increase by feeding, which directly and indirectly inhibits agouti-related protein (AgRP)-expressing neurons through the μ-opioid receptor (MOR). AgRP-specific MOR expression increases by energy surfeit and contributes to opioid-induced suppression of appetite. Conversely, its antagonists diminish suppression of AgRP neuron activity by food and satiety hormones. Mice with AgRP neuron-specific ablation of MOR expression have increased fat preference without increased motivation. These results suggest that post-ingestion release of endogenous opioids contributes to AgRP neuron inhibition to shape food choice through MOR signaling.

Addressing Fear of Negative Consequences of Overdose Response: A Qualitative Study of the Perceptions of Service Industry Workers Who Encounter an Opioid Overdose in an Urban Commercial District in Atlanta, Georgia

BACKGROUND

The increased contamination of illicit drugs with fentanyl in the United States drug market has contributed to escalating mortality from drug overdose. Leisure and hospitality service industry workers are encountering opioid-triggered overdoses in their workplaces, such as restaurants and bars. Consequently, this increases the need for overdose education and naloxone distribution (OEND) training, which has been limited. We aimed to describe the experiences among service industry workers encountering an overdose in their workplace.

METHODS

We conducted in-depth qualitative interviews with service industry workers in Little Five Points (L5P), Atlanta, between October 2019 and April 2020 and triangulated methods with participant observations and fieldwork. Purposive criterion sampling methods were applied to recruit from different establishments in the L5P commercial district, which comprised restaurants, bars, retail shops, and theaters. After an initial seed sample was identified by engaging key stakeholders during fieldwork (business owners, managers, and the business association), a snowball sample followed for a final sample of N = 15. To contextualize the local population of harm reduction workers, people who use drugs and/or obtain safer drug consumption supplies in L5P (sterile syringes, safer using kits, naloxone), and service industry workers and their customers in L5P, the first author volunteered with an Atlanta syringe services program from October 2019 to April 2020. The first author conducted participant observations during the syringe exchange program and field notes were taken during observation (44 hours). This engagement ensured a rich, thick description. We used a pragmatic approach to thematic data analysis for this study. Data were analyzed iteratively and inductively from interviews and observations. Two independent researchers reviewed transcripts to identify passages in the data related to the question of interest. The passages were contextualized within the full data set independently to understand the relationships in developing a theory of what was commonly occurring across participants' experiences, and these relationships led to emerging salient themes regarding encountering an opioid overdose at work.

RESULTS

One salient theme related to overdose response emerged with the service industry workers included fear of negative consequences of overdose response, specifically, fear of disease transmission from artifacts of drug use and overdose response, including the spread of blood-borne disease, violence, and exposure to unintentional overdose. When discussing drug use, participants' beliefs about the potential for personal danger from drug use artifacts (syringes and discarded drugs) and violence were identified as barriers to opioid overdose responses.

CONCLUSIONS/IMPLICATIONS FOR OCCUPATIONAL HEALTH PRACTICE

Our findings provide valuable insights for tailoring OEND training for service industry workers to confront fears associated with opioid overdose response in their places of work to decrease mortality from the opioid epidemic. Harm reduction approaches need to be sensitive to the places in which overdose occurs and who the overdose responder is likely to be, which requires appropriately tailoring OEND training for service industry workers.

Chronic Morphine Induces Adaptations in Opioid Receptor Signaling in a Thalamostriatal Circuit That Are Location Dependent, Sex Specific, and Regulated by μ-Opioid Receptor Phosphorylation

Chronic opioid exposure induces tolerance to the pain-relieving effects of opioids but sensitization to some other effects. While the occurrence of these adaptations is well understood, the underlying cellular mechanisms are less clear. This study aimed to determine how chronic treatment with morphine, a prototypical opioid agonist, induced adaptations to subsequent morphine signaling in different subcellular contexts. Opioids acutely inhibit glutamatergic transmission from medial thalamic (MThal) inputs to the dorsomedial striatum (DMS) via activity at μ-opioid receptors (MORs). MORs are present in somatic and presynaptic compartments of MThal neurons terminating in the DMS. We investigated the effects of chronic morphine treatment on subsequent morphine signaling at MThal-DMS synapses and MThal cell bodies in male and female mice. Surprisingly, chronic morphine treatment increased subsequent morphine inhibition of MThal-DMS synaptic transmission (morphine facilitation) in male, but not female, mice. At MThal cell bodies, chronic morphine treatment decreased subsequent morphine activation of potassium conductance (morphine tolerance) in both male and female mice. In knock-in mice expressing phosphorylation-deficient MORs, chronic morphine treatment resulted in tolerance to, rather than facilitation of, subsequent morphine signaling at MThal-DMS terminals, suggesting phosphorylation deficiency unmasks adaptations that counter the facilitation observed at presynaptic terminals in wild-type mice. The results of this study suggest that the effects of chronic morphine exposure are not ubiquitous; rather adaptations in MOR function may be determined by multiple factors such as subcellular receptor distribution, influence of local circuitry, and sex.

Opioid Treatment in Primary Care: Knowledge and Practical Use of Opioid Therapy

BACKGROUND

Primary care physicians play a key role in initiating opioid therapy. However, knowledge gaps in opioid use and pain management are significant barriers to providing optimal care. This research study aims to investigate the educational needs of primary care physicians regarding opioid therapy and opioid use in pain management.

METHODS

A computer-assisted web interview (CAWI) protocol was used to collect data from primary care physicians. Drug selection criteria, knowledge of opioid substitutes and dosage, and practical use of opioid therapy were evaluated.

RESULTS

While 84% of participating physicians (724 respondents) reported initiating opioid treatment, only a minority demonstrated accurate opioid dosage calculations. Significant discrepancies between physicians' self-perceived knowledge and their clinical skills in opioid prescribing and pain management were observed. In total, 41% of physicians incorrectly indicated dose conversion rates for tramadol (the most frequently used drug according to 65% of responders).

CONCLUSIONS

Targeted educational programs are essential to bridge the knowledge gap and increase physicians' competence in pain management. The proper self-assessment of one's own skills may be the key to improvement. Further research should focus on developing specialized educational courses and decision-support tools for primary care physicians and examining the impact of interprofessional pain management teams on patient outcomes.