Considerations in addressing the opioid epidemic and chronic pain within the USA

Angioembolization in the management of joint pain: current concepts

Joint pain is a common complaint owing to its origin in inflammatory and degenerative joint diseases. Recent research has helped narrow down inadequate angiogenesis as one of the causes. Angioembolization has emerged as a treatment option for this condition when it is refractory to conservative treatment. This review describes angioembolization by elaborating on the mechanism, safety, efficacy, comparative analysis of treatment and the road ahead, in addition to summarizing the existing data on this treatment. The inferences from this review further consolidate transcatheter arterial embolization as one of the prime options for managing joint pain when it is refractory to conservative treatment and label it as one of the most exciting prospects. A limitation of this review is that most of the data were from open label case series or case reports.

Pain Management Treatments and Opioid Use Disorder Risk in Medicaid Patients

INTRODUCTION

People with chronic pain are at increased risk of opioid misuse. Less is known about the unique risk conferred by each pain management treatment, as treatments are typically implemented together, confounding their independent effects. This study estimated the extent to which pain management treatments were associated with risk of opioid use disorder (OUD) for those with chronic pain, controlling for baseline demographic and clinical confounding variables and holding other pain management treatments at their observed levels.

METHODS

Data were analyzed in 2024 from 2 chronic pain subgroups within a cohort of non-pregnant Medicaid patients aged 35-64 years, 2016-2019, from 25 states: those with (1) chronic pain and physical disability (CPPD) (N=6,133) or (2) chronic pain without disability (CP) (N=67,438). Nine pain management treatments were considered: prescription opioid (1) dose and (2) duration; (3) number of opioid prescribers; opioid co-prescription with (4) benzo- diazepines, (5) muscle relaxants, and (6) gabapentinoids; (7) nonopioid pain prescription, (8) physical therapy, and (9) other pain treatment modality. The outcome was OUD risk.

RESULTS

Having opioids co-prescribed with gabapentin or benzodiazepine was statistically significantly associated with a 37-45% increased OUD risk for the CP subgroup. Opioid dose and duration also were significantly associated with increased OUD risk in this subgroup. Physical therapy was significantly associated with an 18% decreased risk of OUD in the CP subgroup.

DISCUSSION

Coprescription of opioids with either gabapentin or benzodiazepines may substantially increase OUD risk. More positively, physical therapy may be a relatively accessible and safe pain management strategy.

Independent and joint contributions of physical disability and chronic pain to incident opioid use disorder and opioid overdose among Medicaid patients

BACKGROUND

Chronic pain has been extensively explored as a risk factor for opioid misuse, resulting in increased focus on opioid prescribing practices for individuals with such conditions. Physical disability sometimes co-occurs with chronic pain but may also represent an independent risk factor for opioid misuse. However, previous research has not disentangled whether disability contributes to risk independent of chronic pain.

METHODS

Here, we estimate the independent and joint adjusted associations between having a physical disability and co-occurring chronic pain condition at time of Medicaid enrollment on subsequent 18-month risk of incident opioid use disorder (OUD) and non-fatal, unintentional opioid overdose among non-elderly, adult Medicaid beneficiaries (2016-2019).

RESULTS

We find robust evidence that having a physical disability approximately doubles the risk of incident OUD or opioid overdose, and physical disability co-occurring with chronic pain increases the risks approximately sixfold as compared to having neither chronic pain nor disability. In absolute numbers, those with neither a physical disability nor chronic pain condition have a 1.8% adjusted risk of incident OUD over 18 months of follow-up, those with physical disability alone have an 2.9% incident risk, those with chronic pain alone have a 3.6% incident risk, and those with co-occurring physical disability and chronic pain have a 11.1% incident risk.

CONCLUSIONS

These findings suggest that those with a physical disability should receive increased attention from the medical and healthcare communities to reduce their risk of opioid misuse and attendant negative outcomes.

Development and feasibility of a mindfulness-based dance/movement therapy intervention for chronic low back pain

Introduction

Responding to the need for innovative, multi-modal, non-pharmacological strategies in chronic low back pain (cLBP) care, this article presents the development and a mixed methods feasibility trial of a manualized Mindfulness-based Dance/Movement Therapy (M-DMT) program for cLBP. The 12-week program is designed as a group therapy, integrating mindfulness principles, creative/expressive dance and movement, and psychoeducational content focused on cLBP management. This holistic program seeks to cultivate nonjudgmental awareness of pain experiences, challenge maladaptive pain-related beliefs, enhance emotional well-being, foster social support, and promote effective coping strategies for the daily challenges associated with cLBP.

Methods

The 12-week M-DMT intervention was administered to individuals with non-specific cLBP (N = 18, aged 51.7 ± 13.9 years, 72% female, 55% Black and 39% White). We assessed feasibility and acceptability through monitoring enrollment and retention rates, attendance, and adverse events. Moreover, we measured the intervention's credibility/expectancy, participants' perception of changes, and overall satisfaction. Additionally, we collected qualitative data, capturing participants' perspectives on the intervention's usefulness and perceived benefits. Specific benchmarks were established to gauge the successful feasibility and acceptability of the program.

Results

The adherence rate stood at 80%, with a perfect retention rate of 100%. The study successfully met the benchmarks for treatment acceptability and satisfaction criteria, with 61% of participants reporting "feeling better" or a "great deal better" after the intervention. No adverse events were observed. Participants found the intervention enjoyable and reported that it provided effective tools for cLBP and related symptoms. Notably, participants reported a decrease in fear-avoidance behaviors, increased motivation for physical activity, and a boost in self-efficacy for pain management.

Discussion

These encouraging findings establish a strong basis for considering the M-DMT intervention as a promising approach for cLBP management, warranting further investigation in larger-scale studies.

Chronic Morphine Leaves a Durable Fingerprint on Whole-Brain Functional Connectivity

BACKGROUND

Opioid use disorder is a chronic relapsing disorder. The brain adapts to opioids that are taken for pain treatment or recreational use so that abstinence becomes a true challenge for individuals with opioid use disorder. Studying brain dysfunction at this stage is difficult, and human neuroimaging has provided highly heterogeneous information.

METHODS

Here, we took advantage of an established mouse model of morphine abstinence together with functional magnetic resonance imaging to investigate whole-brain functional connectivity (FC) first at rest and then in response to an acute morphine challenge during image acquisition.

RESULTS

Hierarchical clustering of seed pair correlation coefficients showed modified FC in abstinent animals, brainwide and regardless of the condition. Seed-to-voxel analysis and random forest classification, performed on data at rest, indicated that the retrosplenial cortex (a core component of the default mode network) and the amygdala (a major aversion center) are the best markers of abstinence, thus validating the translatability of the study. Seed pair network clustering confirmed disruption of a retrosplenial cortex-centered network, reflecting major reorganization of brain FC. The latter analysis also identified a persistent but unreported morphine signature in abstinent mice at rest, which involves cortical and midbrain components and characterizes the enduring morphine footprint. Finally, dynamic FC analysis revealed that the intrascanner acute morphine challenge modified FC faster and more broadly in abstinent animals, demonstrating brainwide adaptations of FC reactivity to an acute opioid challenge.

CONCLUSIONS

This study used a unique experimental design to demonstrate that a prior history of chronic opioid exposure leaves a durable pharmacological signature on brain communication, with implications for pain management and recovery from opioid use disorder.

Lifeworlds in pain: a principled method for investigation and intervention

The experience of pain spans biological, psychological and sociocultural realms, both basic and complex, it is by turns necessary and devastating. Despite an extensive knowledge of the constituents of pain, the ability to translate this into effective intervention remains limited. It is suggested that current, multiscale, medical approaches, largely informed by the biopsychosocial (BPS) model, attempt to integrate knowledge but are undermined by an epistemological obligation, one that necessitates a prior isolation of the constituent parts. To overcome this impasse, we propose that an anthropological stance needs to be taken, underpinned by a Bayesian apparatus situated in computational psychiatry. Here, pain is presented within the context of lifeworlds, where attention is shifted away from the constituents of experience (e.g. nociception, reward processing and fear-avoidance), towards the dynamic affiliation that occurs between these processes over time. We argue that one can derive a principled method of investigation and intervention for pain from modelling approaches in computational psychiatry. We suggest that these modelling methods provide the necessary apparatus to navigate multiscale ontology and epistemology of pain. Finally, a unified approach to the experience of pain is presented, where the relational, inter-subjective phenomenology of pain is brought into contact with a principled method of translation; in so doing, revealing the conditions and possibilities of lifeworlds in pain.

Efficacy of an Opioid-Sparing Perioperative Multimodal Analgesia Protocol on Posterior Lumbar Fusion in a Hispanic Population: A Randomized Controlled Trial

INTRODUCTION

Posterior lumbar fusion surgery has become more common amid an aging population, with degenerative disease as its most common indication. Historically, postoperative pain control for spine surgery has relied on opioids. However, opioid use is associated with adverse effects such as dependence, respiratory depression, and altered cognition. Our study aimed to determine whether an opioid-sparing multimodal analgesia regimen (ketorolac, orphenadrine, and gabapentin) could be a viable alternative to diminish opioid use compared with a standard opioid-based regimen in Hispanic patients undergoing posterior lumbar spinal fusion.

METHODS

This was a randomized controlled trial of Hispanic patients scheduled to undergo elective posterior spinal fusion. Inclusion criteria included age 30 to 85 years, Hispanic ethnicity, lumbar stenosis between L1 and S1, elective posterior spinal fusion with instrumentation, American Society of Anesthesiologists Score <2, and consent to participate in the study. Patients were randomized into two groups, an experimental multimodal analgesia and control (opioid-based) treatment groups, and outcomes such as morphine milligram equivalents used, visual analog scale score, and length of hospital stay were compared between the groups.

RESULTS

The MMA experimental group used significantly lower amounts of opioid (measured with morphine milligram equivalent) than the opioid-based group during the 12-hour and 24-hour postoperative periods ( P -value = 0.023 and P -value = 0.033, respectively). No statistically significant difference was observed in opioid use in the 48-hour postoperative period between both groups ( P -value = 0.066). The MMA group had significantly lower VAS scores reported at the 12-hour, 24-hour, and 48-hour postoperative periods compared with the opioid-based group ( P -values = 0.016, 0.020, and 0.020, respectively). No difference was observed in the length of hospital stay between groups ( P -value = 0.169).

DISCUSSION

Implementing an MMA protocol in Hispanic patients undergoing posterior lumbar fusion resulted in decreased overall opioid use and decreased pain intensity compared with the opioid-based group. MMA is an effective alternative for pain control in patients who want to avoid opioid use.

CLINICAL TRIAL REGISTRATION

Identifier: NCT05413902.

Implementing Telemedicine During the COVID-19 Pandemic: Disparities in Utilization in an Urban Pain Medicine Practice

Purpose

The COVID-19 pandemic led to a drastic expansion in utilizing telemedicine, circumventing some of the geographical barriers to accessing pain care. However, uncertainties around the impact of telemedicine across various sociodemographic groups still exist, prompting further exploration. Therefore, this study aimed to evaluate the impact of sociodemographic factors in telemedicine utilization during and after the COVID-19 pandemic.

Patients and methods

All outpatient non-procedural visits at the pain medicine division of a large academic institution in the epicenter of the pandemic (New York, USA), between March 2019 and October 2021, were retrospectively included. Sociodemographic data including gender, age, ethnicity/race, postal code, and type of health insurance, across three time periods associated with the COVID-19 pandemic - pre-lockdown (in-office visits only), lockdown (telemedicine visits only) and post-lockdown (offering both in-office and telemedicine visits) - were analyzed and compared.

Results

In total, 12,615 unique patients - The majority being women (58%) - were seen during the whole study period. In the post-lockdown period, telemedicine was utilized by 42% of all patients. Follow-up visits, younger patients, white patients, patients residing further away from the hospital, and privately insured patients were more likely to utilize telemedicine post-lockdown (p <0.05). Older patients, minorities, Manhattan residents, and Medicare/Medicaid recipients, were more likely to use in-office visits post-lockdown (p <0.05).

Conclusion

We identified disparities in the utilization of telemedicine in Pain Medicine, which may be due to socioeconomic factors such as lack of access to reliable internet access, cost of devices, and technological know-how. This emphasizes the need for further studies to better understand the reasons for and barriers to telemedicine use. This could help inform policymaking to safeguard equitable access to telemedicine use for pain care.

The Impact of the Florida Law HB21 on Opioid Prescribing Patterns After Spine Surgery

Background

The opioid epidemic represents a major public health issue in the United States and has led to significant morbidity and mortality. On July 1 2018, Florida implemented state-law House Bill 21 (HB21), limiting opioid prescriptions to a 3-day supply for acute pain or 7 days if an exception is documented. The purpose of this study is to evaluate the effects of HB21 on opioid prescribing patterns after spine surgery.

Methods

Patients 18 years and older who underwent spine surgery between January 2017 and January 2021 were eligible for inclusion. Information including demographics, pills, days, and morphine milligram equivalents (MMEs) was obtained via retrospective chart review using the Florida Prescription Drug Monitoring Program and Epic Chart Review. Student's t tests and Fisher's exact tests were used for comparison of continuous variables. Multiple logistic regression was utilized to determine which variables were associated with postoperative opioid prescriptions. p<.05 was considered significant.

Results

We reviewed 114 patients who underwent spine surgery from January 2017 to July 2018 and 264 patients from July 2018 to January 21. There were no significant differences between the groups in age, sex, ethnicity, body mass index, number of levels fused, or preoperative opioid use. The average number of MMEs, pills prescribed and days in the first postoperative prescription decreased significantly after HB21. Multiple logistic regression revealed that the variable most predictive of MMEs and number of pills in the first postoperative prescription was postlaw status (p=.002, p=.50).

Conclusions

Florida law HB21 was successful in decreasing postoperative opioid prescriptions after spine surgery, however, the need for additional progress remains. Legislation should be combined with multimodal pain regimens, as well as patient and provider education in order to further decrease postoperative opioid requirements. Future studies should include a larger number of patients treated by multiple spine surgeons across multiple institutions in order to further evaluate the effects of HB21 on postoperative opioid prescriptions.

Transarterial Embolization for the Treatment of Chronic Musculoskeletal Pain: A Systematic Review of Indications, Safety, and Efficacy

OBJECTIVE

The study objective was to evaluate the safety and efficacy of transcatheter arterial "embolization" (TAE) in the treatment of chronic "musculoskeletal pain" refractory to standard therapy.

METHODS

PubMed, EMBASE, and Cochrane Central Register of Controlled Trials were searched for original research articles evaluating TAE in patients with musculoskeletal conditions from database inception to January 21, 2020. Search terms employed were as follows: "embolization", "pain", "knee osteoarthritis", joint replacement, epicondylitis, tenderness, inflammation, WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index), microspheres, Embozene, geniculate artery, neovascularity, transcatheter, embolic, imipenem/cilastatin sodium, angiogenesis, and "musculoskeletal". Studies involving particle "embolization" for painful musculoskeletal conditions were included. Studies of TAE for hemarthrosis or malignancy-related "musculoskeletal pain" were excluded.

RESULTS

The primary search yielded 1,099 sources; 7 articles and 4 abstracts were included for data extraction. All were cohorts or case series, with low risk of bias and moderate to poor level of evidence. Heterogeneity between studies was high, precluding meta-analysis. The reviewed studies reported the safety and efficacy of TAE for the treatment of "knee osteoarthritis"; adhesive capsulitis of the shoulder; tendinopathy/enthesopathy of the knee, shoulder, elbow, and ankle; and cervical myalgia. All TAEs were reported as technically successful without major complications or subsequent serious adverse events, including no reported osteonecrosis, cutaneous ulceration, limb ischemia, cartilage degeneration, or myotendinous injury. TAE significantly reduced pain and improved function for all of the treated conditions, with durable response up to 24 months post procedure.

CONCLUSION

TAE appears to be a safe and effective treatment for some types of chronic refractory "musculoskeletal pain". Randomized placebo-controlled studies are necessary to confirm these findings.

Immersive virtual reality to relieve exercise-induced pain caused by aerobic cycling

Chronic pain affects 20% of the global population and is incredibly complex to treat. The burden of chronic pain is physical, emotional and financial, and prevalence rates continue to rise. Current treatments are ineffective long-term against pain and common comorbidities, including anxiety and depression, mood and sleep disorders, and social isolation. While a large body of evidence supports regular physical exercise as an effective long-term treatment for chronic pain and its comorbidities, exercise-induced pain and kinesiophobia are significant barriers to participation and adherence. Immersive virtual reality is a powerful short-term pain reliever, that, when combined with exercise, can help overcome these barriers. This perspective argues for the use of combined exercise and virtual reality treatment techniques to mitigate chronic pain.

Buprenorphine Microdosing for the Pain and Palliative Care Clinician

Buprenorphine (BUP) can be a safe and effective alternative to traditional opioids for many patients with chronic pain. For patients on higher doses of opioids, rotation to BUP is complicated by the requirement of an opioid-free interval or withdrawal during the transition. Microdosing inductions, in which BUP is gradually titrated, while full agonist opioids are continued, are a viable alternative to traditional inductions. The objective of this article is to review the current literature on BUP microdosing induction, with a focus on patients using opioids for pain. A literature review of the PubMed database was performed in the United States on articles published from inception to May 2021. A total of 34 publications were included. The most commonly utilized microdosing strategy involved administering divided doses of sublingual (SL) products marketed for opioid use disorder treatment, with 25 (73.5%) articles reporting use of partial SL tablets or films (ranging from 1/8 to 1/2 of a 2 mg product) at some point during the induction. Transdermal patches, low-dose SL BUP available in Europe, intravenous BUP, and buccal BUP have also been used. Beyond the products used, the speed of the microinduction, setting, final BUP dosing, and management of concomitant full agonists vary widely in the literature. Microdosing regimens should be individualized based on local guidelines and patient-specific factors. Further studies comparing the safety and efficacy of different protocols are warranted.

Dediagnosing - a novel framework for making people less ill

Diagnosing constitutes a substantial part of healthcare work and triggers a wide range of actions including the prescription of medicines. Dediagnosing is proposed as a novel framework for removing diagnoses that do not contribute to the reduction of persons' suffering and should be introduced to make people less ill. Dediagnosing comes together with other efforts to reduce overuse, such as deimplementation, deprescribing, decommissioning, and disinvestment. Because diagnoses may influence identity construction and social rights, dediagnosing must be conducted in close collaboration with the patient.

Stimulation of the dorsal root ganglion using an Injectrode®

Objective. The goal of this work was to compare afferent fiber recruitment by dorsal root ganglion (DRG) stimulation using an injectable polymer electrode (Injectrode^®) and a more traditional cylindrical metal electrode.Approach. We exposed the L6 and L7 DRG in four cats via a partial laminectomy or burr hole. We stimulated the DRG using an Injectrode or a stainless steel (SS) electrode using biphasic pulses at three different pulse widths (80, 150, 300μs) and pulse amplitudes spanning the range used for clinical DRG stimulation. We recorded antidromic evoked compound action potentials (ECAPs) in the sciatic, tibial, and common peroneal nerves using nerve cuffs. We calculated the conduction velocity of the ECAPs and determined the charge-thresholds and recruitment rates for ECAPs from Aα, Aβ, and Aδfibers. We also performed electrochemical impedance spectroscopy measurements for both electrode types.Main results. The ECAP thresholds for the Injectrode did not differ from the SS electrode across all primary afferents (Aα, Aβ, Aδ) and pulse widths; charge-thresholds increased with wider pulse widths. Thresholds for generating ECAPs from Aβfibers were 100.0 ± 32.3 nC using the SS electrode, and 90.9 ± 42.9 nC using the Injectrode. The ECAP thresholds from the Injectrode were consistent over several hours of stimulation. The rate of recruitment was similar between the Injectrodes and SS electrode and decreased with wider pulse widths.Significance. The Injectrode can effectively excite primary afferents when used for DRG stimulation within the range of parameters used for clinical DRG stimulation. The Injectrode can be implanted through minimally invasive techniques while achieving similar neural activation to conventional electrodes, making it an excellent candidate for future DRG stimulation and neuroprosthetic applications.

A social affective neuroscience lens on placebo analgesia

Pain is a fundamental experience that promotes survival. In humans, pain stands at the intersection of multiple health crises: chronic pain, the opioid epidemic, and health disparities. The study of placebo analgesia highlights how social, cognitive, and affective processes can directly shape pain, and identifies potential paths for mitigating these crises. This review examines recent progress in the study of placebo analgesia through affective science. It focuses on how placebo effects are shaped by expectations, affect, and the social context surrounding treatment, and discusses neurobiological mechanisms of placebo, highlighting unanswered questions and implications for health. Collaborations between clinicians and social and affective scientists can address outstanding questions and leverage placebo to reduce pain and improve human health.

Recruitment of Primary Afferents by Dorsal Root Ganglion Stimulation using the Injectrode

Chronic pain affects millions of people in the United States and pharmacological treatments have been ineffective. Dorsal root ganglion (DRG) stimulation is a neuromodulation method that delivers electrical stimulation to the DRG to relieve pain. DRG electrodes are rigid and cylindrical. The implantation of DRG electrodes requires a technically-challenging surgery that involves steering electrodes laterally towards the DRG. The Injectrode is an injectable conductive polymer that cures in place and is capable of delivering electrical current to stimulate neural tissue. We used the Injectrode to stimulate the L6 and L7 DRG in cats, measuring neural responses evoked in the sciatic, tibial, and common peroneal nerves to measure the thresholds for activating fibers. A cylindrical stainless-steel electrode was used for comparison. Thresholds were 38% higher with the Injectrode versus stainless-steel, likely owing to its larger contact surface area with the DRG. Both Aα and Aβ sensory fibers were activated using DRG stimulation. The Injectrode has the potential to offer a new and simple method for DRG stimulation that can potentially offer more complete coverage of the DRG.

Opioid Addiction and Opioid Receptor Dimerization: Structural Modeling of the OPRD1 and OPRM1 Heterodimer and Its Signaling Pathways

Opioid addiction is a complex phenomenon with genetic, social, and other components. Due to such complexity, it is difficult to interpret the outcome of clinical studies, and thus, mutations found in individuals with these addictions are still not indisputably classified as opioid addiction-causing variants. Here, we computationally investigated two such mutations, A6V and N40D, found in the mu opioid receptor gene OPRM1. The mutations are located in the extracellular domain of the corresponding protein, which is important to the hetero-dimerization of OPRM1 with the delta opioid receptor protein (OPRD1). The hetero-dimerization of OPRD1-OPRM1 affects the signaling pathways activated by opioids and natural peptides and, thus, could be considered a factor contributing to addiction. In this study, we built four 3D structures of molecular pathways, including the G-protein signaling pathway and the β-arrestin signaling pathway of the heterodimer of OPRD1-OPRM1. We also analyzed the effect of mutations of A6V and N40D on the stability of individual OPRM1/OPRD1 molecules and the OPRD1-OPRM1 heterodimer with the goal of inferring their plausible linkage with opioid addiction. It was found that both mutations slightly destabilize OPRM1/OPRD1 monomers and weaken their association. Since hetero-dimerization is a key step for signaling processes, it is anticipated that both mutations may be causing increased addiction risk.

The Effect of Literacy-Adapted Psychosocial Treatments on Biomedical and Biopsychosocial Pain Conceptualization

This is a secondary data analysis of a subgroup of participants who received the Learning About My Pain (LAMP) intervention (clinicaltrials.gov identifier NCT01967342). We examined the effects of LAMP on pre-to-post changes in biomedical and biopsychosocial pain conceptualization and whether those changes in pain conceptualization were associated with physical and psychological functioning. Participants were randomized into three conditions: Cognitive Behavioral Therapy (CBT), Pain Psychoeducation (EDU), or Usual Medical Care (UC). Results based on 225 participants who completed the Pain Concepts Questionnaire (PCQ) showed a pre-to-post reduction in biomedical pain conceptualization (BM), an increase in biopsychosocial pain conceptualization (BPS), and an increase in BPS/BM ratio for CBT and EDU but not UC. There were no differences between CBT and EDU in post-treatment PCQ scores. Compared to those with lower BM pain beliefs scores at post-treatment, participants endorsing higher BM pain beliefs scores reported greater pain intensity and greater pain interference. Furthermore, higher BM pain beliefs scores at post-treatment and lower BPS/BM ratio were associated with higher levels of pain catastrophizing. Overall, results of this study suggest the need for targeting specific pain beliefs that influence pain-related outcomes. PERSPECTIVE: This article presents the potential benefits of providing literacy-adapted psychosocial treatments to expand pain conceptualization beyond a biomedical-only understanding and toward a biopsychosocial conceptualization of the experience of pain. Furthermore, the association of changes in pain conceptualization and pain-related functioning argues for its potential clinical relevance.

Meta-analysis of retrospective studies suggests that the pre-operative opioid use is associated with an increased risk of adverse outcomes in total hip and or knee arthroplasty

BACKGROUND

Opioid use is prevalent in the general population. This systematic review and meta-analysis sought to evaluate whether it affects patient-reported outcomes (PROs) following total hip or knee arthroplasty.

METHODS

The following databases were systematically searched on February 5, 2020: Medline, Embase (Ovid), Cochrane Library, and Web of Science. Studies were included if they compared patients who received opioids or not before total hip or knee arthroplasty. Outcomes of interest were rates of post-operative revision, peri-prosthetic infection, and readmission.

RESULTS

Ten retrospective studies were included for review. Pre-operative opioid use was identified as a risk factor for post-operative revision [odds ratio (OR) 1.58, 95% confidence interval (CI) 1.15-1.73, p<0.01], peri-prosthetic infection (OR 1.36, 95% CI 1.08-1.71, p=0.01), and readmission (OR 1.41, 95% CI 1.20-1.75, p<0.01).

CONCLUSION

The available evidence indicates that pre-operative opioid use increases the risk of adverse outcomes following total hip or knee arthroplasty. Orthopedic physicians should consider these risks when treating their patients.

Isolation and Pharmacological Characterization of Six Opioidergic Picralima nitida Alkaloids

The seeds of the akuamma tree (Picralima nitida) have been used as a traditional treatment for pain and fever. Previous studies have attributed these effects to a series of indole alkaloids found within the seed extracts; however, these pharmacological studies were significantly limited in scope. Herein, an isolation protocol employing pH-zone-refining countercurrent chromatography was developed to provide six of the akuamma alkaloids in high purity and quantities sufficient for more extensive biological evaluation. Five of these alkaloids, akuammine (1), pseudo-akuammigine (3), akuammicine (4), akuammiline (5), and picraline (6), were evaluated against a panel of >40 central nervous system receptors to identify that their primary targets are the opioid receptors. Detailed in vitro investigations revealed 4 to be a potent kappa opioid receptor agonist, and three alkaloids (1-3) were shown to have micromolar activity at the mu opioid receptor. The mu opioid receptor agonists were further evaluated for analgesic properties but demonstrated limited efficacy in assays of thermal nociception. These findings contradict previous reports of the antinociceptive properties of the P. nitida alkaloids and the traditional use of akuamma seeds as analgesics. Nevertheless, their opioid-preferring activity does suggest the akuamma alkaloids provide distinct scaffolds from which novel opioids with unique pharmacologic properties and therapeutic utility can be developed.

The Impact of Music on Nociceptive Processing

OBJECTIVE

Music has been shown to modulate pain, although the impact of music on specific aspects of nociceptive processing is less well understood. Using quantitative sensory testing (QST), we assessed the impact of a novel music app on specific aspects of nociceptive processing.

DESIGN

Within-subjects paired comparison of pain processing in control vs music condition.

SETTING

Human psychophysical laboratory.

SUBJECTS

Sixty healthy adult volunteers.

METHODS

Subjects were assessed for baseline anxiety, depression, and catastrophizing using validated questionnaires. QSTs measured included 1) pain threshold and tolerance to deep muscle pressure, 2) pain with mechanical pinprick, 3) temporal summation of pain (TSP) with a repeated pain stimulus, and 4) conditioned pain modulation (CPM) with a second painful stimulus. QSTs were performed in the absence and presence of music delivered through a music app.

RESULTS

We found an increase in pressure pain thresholds in both the forearm (P = 0.007) and trapezius (P = 0.002) with music, as well as a decrease in the amount of pinprick pain (P < 0.001) and TSP (P = 0.01) with music. Interestingly, CPM was also significantly diminished (P < 0.001) in the music condition. No significant difference in cold pain, anxiety, or situational catastrophizing was observed with music. Higher baseline pain catastrophizing scores were associated with less music-induced pressure pain reduction.

CONCLUSIONS

Several measures of mechanical pain sensitivity were reduced with music. TSP, a measure of central sensitization, also decreased with music, but CPM, a measure of descending modulation of pain, was not further augmented by music.

Turning the 'Tides on Neuropsychiatric Diseases: The Role of Peptides in the Prefrontal Cortex

Recent advancements in technology have enabled researchers to probe the brain with the greater region, cell, and receptor specificity. These developments have allowed for a more thorough understanding of how regulation of the neurophysiology within a region is essential for maintaining healthy brain function. Stress has been shown to alter the prefrontal cortex (PFC) functioning, and evidence links functional impairments in PFC brain activity with neuropsychiatric disorders. Moreover, a growing body of literature highlights the importance of neuropeptides in the PFC to modulate neural signaling and to influence behavior. The converging evidence outlined in this review indicates that neuropeptides in the PFC are specifically impacted by stress, and are found to be dysregulated in numerous stress-related neuropsychiatric disorders including substance use disorder, major depressive disorder (MDD), posttraumatic stress disorder, and schizophrenia. This review explores how neuropeptides in the PFC function to regulate the neural activity, and how genetic and environmental factors, such as stress, lead to dysregulation in neuropeptide systems, which may ultimately contribute to the pathology of neuropsychiatric diseases.

Episodic future thinking reduces chronic pain severity: A proof of concept study

BACKGROUND

Chronic pain is a major public health challenge in the United States and around the world. Current treatments including opioid analgesics and cognitive behavioral therapy possess harmful side effects or limited efficacy, respectively. Chronic pain is associated with a variety of unhealthy behaviors including opioid misuse. Moreover, individuals who suffer from chronic pain exhibit excessive discounting of delayed rewards, suggesting a constricted temporal window of valuation. Reductions in the excessive discounting of delayed rewards has been achieved with Episodic Future Thinking (EFT; vividly imagining realistic future events). EFT has also been associated with reductions in a variety of unhealthy behaviors. In this study, the effects of EFT on delay discounting and levels of pain were investigated in individuals reporting chronic pain.

METHODS

Individuals reporting chronic pain (N = 250; 42.4 % female) were recruited through the Amazon Mechanical Turk platform. Measures of delay discounting and pain were collected at baseline and again after randomization to EFT (N = 128) or Control Episodic Thinking (CET) (N = 122).

RESULTS

EFT significantly reduced delay discounting relative to baseline (p < 0.001) and EFT reduced pain scores in a baseline dependent manner (p = 0.001) when compared to CET; that is, those with the greatest reports of pain experienced the greatest reduction. Furthermore the reduction in delay discounting fully mediated the reduction in pain.

CONCLUSIONS

These findings suggest that Episodic Future Thinking, by widening the temporal window, may reduce pain in those reporting chronic pain and therefore represents a potential novel therapeutic.

Reintegrating droperidol into emergency medicine practice

Purpose

After a long period of low utilization, droperidol has become easier to obtain in the US market. This comprehensive review discusses the safety, indications, clinical efficacy, and dosing of droperidol for use in the emergency department (ED) setting.

Summary

In 2001 the US Food and Drug Administration (FDA) mandated a boxed warning in the labeling of droperidol after reports of QT interval prolongation associated with droperidol use. Since that time, it has been difficult to access droperidol in the United States; as a result, many practicing clinicians lack experience in its clinical use. Multiple studies have been conducted to assess the clinical efficacy and safety of droperidol use in ED patients. Results consistently show the safety of droperidol and its clinical efficacy when used as an analgesic, antiemetic, and sedative. Now that droperidol is more widely available for use in the US market, pharmacists and prescribers need to reliably translate safety and efficacy data compiled since 2001 to help ensure appropriate and effective use of the medication.

Conclusion

Droperidol is an effective and safe option for the treatment of acute agitation, migraine, nausea, and pain for patients in the ED setting. Healthcare professionals can adopt droperidol for use in clinical practice, and they should become familiar with how to dose and monitor droperidol for safe and effective use.

Medical cannabis for orthopaedic patients with chronic musculoskeletal pain: does evidence support its use?

The treatment of chronic, non-cancer musculoskeletal pain has become a topic growing interest as it is believed to be one of the reasons for the current opioid epidemic. The medicinal use of cannabis has a long history as a number of active compounds in cannabis have been shown to interact with the body's endocannabinoid system to reduce pain. This position paper provides a history on the evolution of cannabis, the science behind its therapeutic effects, and review of the evidence and current guideline recommendations on its use as a treatment for patients with chronic, non-cancer musculoskeletal pain. Results from systematic reviews have demonstrated a statistically significant reduction in chronic pain conditions with cannabinoids, compared with placebo, although the effects might be considered small and did not reach the minimally important difference. More adverse events were reported in the cannabinoid group than in the placebo group with longer than 2 weeks of treatment. There is a lack of evidence on dependence. With changes to policies, patients' perception has changed to be more positive toward the use of medical cannabis. Current recommendations from North America, Latin America, Europe, Australia and Iran support the use of medical cannabis for chronic, non-cancer pain. Based on the current evidence, it is our position that cannabinoids may be considered as an adjunctive therapy after recommended first- and second-line therapies have failed to provide sufficient efficacy or tolerability. Patients should consider the balance between the desirable and undesirable effects of taking cannabis for chronic pain, and comprehensively consider their own values and preferences, as well as cost-effectiveness factors, based on the information provided by their physician.

Use of cannabidiol (CBD) for the treatment of chronic pain

Chronic pain can be recurrent or constant pain that lasts for longer than 3 months and can result in disability, suffering, and a physical disturbance. Related to the complex nature of chronic pain, treatments have a pharmacological and non-pharmacological approach. Due to the opioid epidemic, alternative therapies have been introduced, and components of the plant Cannabis Sativa, Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) have gained recent interest as a choice of treatment. The exact mechanism for CBD is currently unknown, but unlike the CBD's psychoactive counterpart, THC, the side effects of CBD itself have been shown to be overall much more benign. The current pharmaceutical products for the treatment of chronic pain are known as nabiximols, and they contain a ratio of THC combined with CBD, which has been promising. This review focuses on the treatment efficacy of CBD, THC: CBD-based treatments for chronic pain and adverse events with each.

The Negative Affect of Protracted Opioid Abstinence: Progress and Perspectives From Rodent Models

Opioid use disorder (OUD) is characterized by the development of a negative emotional state that develops after a history of long-term exposure to opioids. OUD represents a true challenge for treatment and relapse prevention. Human research has amply documented emotional disruption in individuals with an opioid substance use disorder, at both behavioral and brain activity levels; however, brain mechanisms underlying this particular facet of OUD are only partially understood. Animal research has been instrumental in elucidating genes and circuits that adapt to long-term opioid use or are modified by acute withdrawal, but research on long-term consequences of opioid exposure and their relevance to the negative affect of OUD remains scarce. In this article, we review the literature with a focus on two questions: 1) Do we have behavioral models in rodents, and what do they tell us? and 2) What do we know about the neuronal populations involved? Behavioral rodent models have successfully recapitulated behavioral signs of the OUD-related negative affect, and several neurotransmitter systems were identified (i.e., serotonin, dynorphin, corticotropin-releasing factor, oxytocin). Circuit mechanisms driving the negative mood of prolonged abstinence likely involve the 5 main reward-aversion brain centers (i.e., nucleus accumbens, bed nucleus of the stria terminalis, amygdala, habenula, and raphe nucleus), all of which express mu opioid receptors and directly respond to opioids. Future work will identify the nature of these mu opioid receptor-expressing neurons throughout reward-aversion networks, characterize their adapted phenotype in opioid abstinent animals, and hopefully position these primary events in the broader picture of mu opioid receptor-associated brain aversion networks.

Anesthesia and Chronic Pain Management

The reasons for development of chronic pain are poorly understood. Chronic postoperative pain is linked to severe acute postoperative pain. Head and neck pain is often a complex phenomenon that requires meticulous diagnosis and treatment. Institution of early multimodal analgesic regimens by multidisciplinary teams may attenuate chronic pain formation and propagation in the otolaryngologic patient.