Eastern Pain Association Annual Meeting 2019 Abstract Session Award Winners [Meeting Abstract]
(1) Spinal Cord Microglial Phenotypic Changes Following Sciatic Nerve Crush in CD137LKO Mice / David Nicholas, Kinuyo Ohara, Ling Cao -- (2) Notalgia Paresthetica Successfully Treated with Cervical Epidural Injection and Occipital Nerve Block: A Case Report / Fabienne Saint-Preux, Justin Mendoza, Salvador Portugal
Long-term treatment with capsaicin 8% patches: A subgroup analysis in patients with postherpetic neuralgia from an open-label study [Meeting Abstract]
Purpose Painful neuropathy or peripheral neuropathic pain (PNP) is a common neurological condition estimated to affect ~7-8% of the general population in Europe. Managing patients with PNP is challenging; it often becomes chronic and can have a significant impact on quality of life. According to the revised International Association for the Study of Pain (IASP) recommendations for ICD11, PNP is considered to be a distinct chronic pain condition (Scholz et al., 2019)1. Postherpetic neuralgia (PHN) following shingles infection, has specifically been named as one of the PNP conditions. High concentration 8% capsaicin patch (HCCP) is commonly recommended as a second line therapy for PHN. HCCP is indicated for the treatment of peripheral neuropathic pain (PNP) in the EU and for the treatment of neuropathic pain associated with postherpetic neuralgia (PHN) and for neuropathic pain associated with diabetic peripheral neuropathy (DPN) of the feet in the US. Capsaicin is a highly selective, potent and highaffinity exogenous agonist for the transient receptor potential cation channel subfamily V member 1 (TRPV1) receptors which, through a combination of activities, defunctionalizes nociceptor fibers and reduces cutaneous hypersensitivity. As a result, capsaicin is an attractive peripherally acting treatment to control localized pain, hyperalgesia, or allodynia (Anand and Bley, 2011)2. The HCCP delivers the drug effectively and directly to the skin while limiting the risk of systemic effects and drug interactions. Whilst controlled trials have demonstrated the safety and effectiveness of capsaicin patches, the STRIDE study was designed to investigate the long-term safety of repeated patch administration in patients with non-diabetic neuropathic pain (Galvez et al., 2017)3. The present analysis considers the effect on treatment outcomes among a subgroup of patients with PHN included in the STRIDE study. Methods The STRIDE study was an open-label, multicenter, 52-week observational trial conducted in Europe. A diagnosis of PHNwas based on pain persisting since shingles vesicle crusting, for a minimum of 3 months. Prior treatment with capsaicin patches and a history of diabetes were among the exclusion criteria. Patients received up to 6 capsaicin 640 g/cm2 (8% weight for weight) HCCP treatments at 9-to 12-week intervals. At each application visit, a maximum of 4 patches equivalent to an area of up to 1120 cm2 were applied for 60 minutes. HCCP retreatment was at the investigator's discretion and according to patient feedback. Long-term tolerability and safety were the primary objectives of the study. In addition, areas of spontaneous pain and allodynia were monitored, and various scales were used to assess pain, quality of life and overall treatment outcome at each retreatment assessment timepoint. Descriptive statistics (including means and standard deviations) are presented; missing observations were not imputed. Results Of the 107 PHN patients included in the study, 66 completed the trial. The reason for withdrawal was lack of efficacy (14.95%), adverse events in (4.67%) and other reasons (18.69%). HCCP was applied once in 22 patients, twice in 26, three times in 24 and >=4 times in 35. All but 1 patient used preapplication topical anesthesia during the study, and 79.4% used concomitant medications for neuropathic pain. 73% of patients experienced possible or probable drugrelated adverse events, mostly associated with transient application site reactions (57.9%). The maximum severity was mild or moderate in 57% of cases, and only 1 drug-related event required treatment discontinuation. The average daily pain score was reduced from a baseline value of 6.6 (SD, 1.46) to 5.0 (1.99) after 6 months and 4.6 (2.18) after 12 months. The overall change in mean daily pain intensity by the end of study was approximately -1.7. The proportion of responders (>=30% decrease from baseline on a Numerical Pain Rating Scale) progressively increased during the study, to 22.7% after 3 months, and 33.3% and 39.7% after 6 and 12 months, respectively. Over 50% of patients showed at least minimal improvement according to the assessment of their condition by the end of study. The area of allodynia/ hyperplasia and the extent of spontaneous pain (reported in most patients at baseline, mainly on the torso) decreased during the study by just over 20%. Conclusions HCCP repeat application over 12 months in patients with PHN was well tolerated, with mostly transient local adverse events directly linked to the site of application. Progressive and sustained reduction in pain intensity was achieved, as well as reductions in the area of allodynia and spontaneous pain. Overall, the findings from this study demonstrate that repeated HCCP application is a well-tolerated and effective long-term treatment option in patients with PHN
Variations of Technique in Transforaminal Epidural Steroid Injections and Periprocedural Practices by Interventional Pain Medicine Physicians in the United States
BACKGROUND:Interlaminar and transforaminal epidural steroid injections (ILESI and TFESI) are commonly performed procedures. However, the United States Food and Drug Administration has required the addition of drug warning labels for injectable corticosteroids. Updated evidence and scrutiny from regulatory agencies may affect practice patterns. OBJECTIVE:To characterize TFESI practices as well as to provide an update on periprocedural practices for any type of epidural steroid injection (ESI), we surveyed pain medicine physicians in the United States. STUDY DESIGN AND SETTING/METHODS:This was a cross-sectional survey of pain medicine physicians in the United States. METHODS:A web-based survey was distributed to pain medicine physicians in the United States selected from the Accreditation Council for Graduate Medical Education accredited pain medicine fellowship program list as well as the American Society of Interventional Pain Physicians membership database. Physicians were queried about TFESI practices, including needle size, use of image guidance, methods to detect vascular uptake, and preference for injectate. RESULTS:A total of 249 responses were analyzed. Only a minority of respondents reported performing cervical TFESI. There were variations in needle size, methods to detect vascular uptake, and choice of injectate. There were also variations in monitoring practices. LIMITATIONS/CONCLUSIONS:The response rate is a limitation. Thus the results may not be representative of all US pain medicine physicians. CONCLUSIONS:Though all respondents used image guidance for TFESI, variations in other TFESI practices exist. There are also differences in periprocedural practices. Since the closure of this survey, a multisociety pain workgroup published recommendations regarding ESI practices. Our survey findings support the need for more evidence-based guidelines regarding ESI. KEY WORDS/UNASSIGNED:Epidrual steroid injections, transforaminal epidural steroid injection, steroids, local anesthetic, survey, interventional pain.
The Role of Lofexidine in Management of Opioid Withdrawal
Fear of withdrawal symptoms has been cited by survey respondents as the main reason that they continued to use opioids. Lofexidine is an Î±2-adrenergic agonist that decreases the sympathetic outflow that results in the characteristic symptoms of opioid withdrawal. A structural analog of clonidine, lofexidine has a higher affinity and specificity for the Î±2a receptors and does not reinforce opioid dependence. Withdrawal symptoms correlate approximately to the half-life of the opioid; patient factors such as age, duration of opioid exposure, physical status, and other considerations may influence the nature and duration of withdrawal symptoms. For patients with opioid use disorder and psychiatric comorbidities, withdrawal may be destabilizing and may exacerbate mental health status. Lofexidine has been shown in clinical trials to be safe and effective in helping to manage the symptoms of withdrawal and has been recommended in guidelines for this purpose. Adverse events associated with lofexidine include QT prolongation, hypotension, orthostasis, and bradycardia. The maximum course of treatment is 14Â days, and doses should be titrated, with the recommended maximum dose to coincide with the most severe withdrawal symptoms (about 5-7Â days after opioid discontinuation).
The MIST Guidelines: The Lumbar Spinal Stenosis Consensus Group Guidelines for Minimally Invasive Spine Treatment
BACKGROUND:Lumbar spinal stenosis (LSS) can lead to compression of neural elements and manifest as low back and leg pain. LSS has traditionally been treated with a variety of conservative (pain medications, physical therapy, epidural spinal injections) and invasive (surgical decompression) options. Recently, several minimally invasive procedures have expanded the treatment options. METHODS:The Lumbar Spinal Stenosis Consensus Group convened to evaluate the peer-reviewed literature as the basis for making Minimally Invasive Spine Treatment (MIST) recommendations. Eleven consensus points were clearly defined with evidence strength, recommendation grade, and consensus level using United States Preventive Services Task Force (USPSTF) criteria. The Consensus Group also created a treatment algorithm. Literature searches found 9 studies (2 randomized controlled trials or RCTs; 7 observational studies, 4 prospective and 3 retrospective) of minimally invasive spine treatments, and 1 RCT for spacers. RESULTS:The LSS treatment choice is dependent on the degree, spinal or anatomic level, and architecture of the stenosis, the severity of the symptoms, failed, past, less-invasive treatments, previous fusions or other open surgical approaches, and patient comorbidities. There is Level I evidence for percutaneous image-guided lumbar decompression (PILD) as superior to lumbar epidural steroid injection, and 1 RCT supporting spacer use in a non-inferiority study comparing 2 spacer products currently available. CONCLUSIONS:Minimally invasive spine treatments should be used in a judicious and algorithmic fashion to treat LSS, based on the evidence of efficacy and safety in the peer-reviewed literature. The MIST Consensus Group recommend that these procedures be used in a multimodal fashion as part of an evidence-based decision algorithm.
Variations in Interlaminar Epidural Steroid Injection Practice Patterns by Interventional Pain Management Physicians in the United States
BACKGROUND:Previous surveys have identified variations in practice patterns related to epidural steroid injections. Since then, the United States Food and Drug Administration (FDA) has required the addition of drug warning labels for injectable corticosteroids. Updated evidence, as well as scrutiny from regulatory agencies, may affect practice patterns. OBJECTIVE:To provide an update on interlaminar epidural steroid injection (ILESI) practice patterns, we surveyed interventional pain management (IPM) physicians in the United States. STUDY DESIGN AND SETTING/METHODS:This was a cross-sectional survey of IPM physicians in the United States. METHODS:A web-based survey was distributed to IPM physicians in the United States selected from the Accreditation Council for Graduate Medical Education accredited pain medicine fellowship program list as well as the American Society of Interventional Pain Physicians membership database. Physicians were queried about ILESI practices, including needle size, use of image guidance, level of injection, identification of the epidural space, and preference for injectate. RESULTS:A total of 249 responses were analyzed. All respondents used image guidance for ILESI. There were variations in needle size, use of contrast, number of fluoroscopic views utilized, technique for identifying the epidural space, and choice of injectate. LIMITATIONS/CONCLUSIONS:The response rate is a limitation, thus the results may not be representative of all United States IPM physicians. CONCLUSIONS:Though all respondents used image guidance for ILESI, variations in other ILESI practices still exist. Since the closure of this survey, a multi-society pain workgroup published recommendations regarding ESI practices. Our survey findings support the need for more evidence-based guidelines regarding ESI. KEY WORDS/UNASSIGNED:Epidural injection, epidural steroids, survey, low back pain, neck pain, technique.
Opioid-sparing Effects of SoluMatrix Indomethacin in a Phase 3 Study in Patients with Acute Postoperative Pain
OBJECTIVES: To report the opioid-sparing effects of SoluMatrix indomethacin, developed using SoluMatrix Fine Particle Technology, in a phase 3 study in patients with acute pain following bunionectomy. METHODS: This phase 3, placebo-controlled study randomized 462 patients with moderate-to-severe pain following bunionectomy surgery to receive SoluMatrix indomethacin 40 mg three times daily, SoluMatrix indomethacin 40 mg twice daily, SoluMatrix indomethacin 20 mg three times daily, celecoxib 400-mg loading dose followed by 200 mg twice daily, or placebo. Patients were permitted to receive opioid-containing rescue medication throughout the study. The proportion of patients who used rescue medication and the amount of rescue medication used on the first (0-24 h) and second (>24-48 h) days following initial dose of study medication, as well as time to first rescue medication use, were assessed. RESULTS: Significantly fewer patients who received SoluMatrix indomethacin 40 mg or 20 mg three times daily used opioid-containing rescue medication on day 1 compared with those receiving placebo (P=0.034), and fewer patients in all active treatment groups used rescue medication during the second day compared with those in the placebo group (P<0.001). All active treatment groups used significantly fewer rescue medication tablets on days 1 and 2 following randomization compared with placebo (P<0.001). The most common adverse events were nausea, postprocedural edema, and headache. DISCUSSION: SoluMatrix indomethacin was associated with opioid-sparing effects in patients with acute postoperative pain.
New York Physicians' Perspectives and Knowledge of the State Medical Marijuana Program
Introduction: In 2014, New York (NY) became the 23rd state to legalize medical marijuana (MMJ). The purpose of this survey was to collect data about practicing NY physicians' comfort level, opinions, and experience in recommending or supporting patient use of MMJ. Materials and Methods: An anonymous web-based survey was distributed to medical societies and to academic departments in medical schools within NY. Results: A total of 164 responses were analyzed. Physician participants were primarily located in New York City and surrounding areas. The majority (71%) agreed that MMJ should be an option available to patients. Most respondents were not registered to certify MMJ in NY, but were willing to refer patients to registered physicians. Common reasons for not registering included specialty and federal status of cannabis. More than 75% reported having patients who used cannabis for symptom control, and 50% reported having patients who inquired about MMJ within the past year. Most respondents are willing to discuss MMJ with their patients, but had little familiarity with the state program and a modest knowledge of the endocannabinoid system. Pain was a common symptom for which cannabis was recommended by registered physicians (69%) and purportedly used by patients (83%). Most respondents would consider MMJ as an adjuvant to opioids, and 84% believed opioids have greater risks than MMJ. Conclusion: Given that the majority of surveyed physicians support MMJ as an option for patients, few are registered and have adequate knowledge of MMJ. Although our study sample is small and geographically limited, our survey results highlight key physician issues that are likely applicable to practitioners in other states. Concerted efforts are needed at the federal, state, and academic levels to provide practitioners with evidence-based guidelines for the safe use of MMJ.
Endoscopic pulsed radiofrequency ablation of genicular nerves for the treatment of chronic knee pain
Chronic knee pain is the second most common cause of chronic pain in the United States. Occasionally, patients become refractory to conventional treatments such as intraarticular cortisone injections and viscosupplementation. Patients who have exhausted these therapies or have a contraindication to the therapies may be candidates for diagnostic genicular nerve block and if successful, subsequent radiofrequency ablation (RFA). For patients who have undergone image-guided genicular nerve radiofrequency ablation with fluoroscopic or ultrasound guidance without success, an endoscopic approach can be used as an alternative modality with success. With direct visualization of the genicular nerves, the likelihood of success with an endoscopic approach increases as some patients can have varying anatomy of the genicular nerves for which cannot always be detected with fluoroscopy or ultrasound. The purpose of this study is to demonstrate the utilization of a direct endoscopic approach for genicular nerve RFA for patients with chronic knee pain that have failed to improve after image-guided genicular RFA with fluoroscopic or ultrasound guidance. Two patients who had underwent successful diagnostic genicular nerve blocks were assessed for pre-procedure and post-procedure visual analog scale (VAS) scores following endoscopic genicular nerve RFA after failure of the conventional image guided approach at 6 and 12 months. Both patients reported greater than 80% reduction in VAS score and improvement in function at 6 and 12 months Limitations of the current study is a limited number of patients, and lack of the use of a formal functional scale to demonstrate improvement. Ultimately, the conclusion was drawn that an endoscopically-guided genicular nerve RFA can be utilized successfully due to direct visualization of the genicular nerves when conventional approaches with Fluoroscopic/ultrasound guidance has failed to achieve analgesia and functional improvement.
Responsible, Safe, and Effective Prescription of Opioids for Chronic Non-Cancer Pain: American Society of Interventional Pain Physicians (ASIPP) Guidelines
BACKGROUND: Opioid use, abuse, and adverse consequences, including death, have escalated at an alarming rate since the 1990s. In an attempt to control opioid abuse, numerous regulations and guidelines for responsible opioid prescribing have been developed by various organizations. However, the US opioid epidemic is continuing and drug dose deaths tripled during 1999 to 2015. Recent data show a continuing increase in deaths due to natural and semisynthetic opioids, a decline in methadone deaths, and an explosive increase in the rates of deaths involving other opioids, specifically heroin and illicit synthetic fentanyl. Contrary to scientific evidence of efficacy and negative recommendations, a significant proportion of physicians and patients (92%) believe that opioids reduce pain and a smaller proportion (57%) report better quality of life. In preparation of the current guidelines, we have focused on the means to reduce the abuse and diversion of opioids without jeopardizing access for those patients suffering from non-cancer pain who have an appropriate medical indication for opioid use. OBJECTIVES: To provide guidance for the prescription of opioids for the management of chronic non-cancer pain, to develop a consistent philosophy among the many diverse groups with an interest in opioid use as to how appropriately prescribe opioids, to improve the treatment of chronic non-cancer pain and to reduce the likelihood of drug abuse and diversion. These guidelines are intended to provide a systematic and standardized approach to this complex and difficult arena of practice, while recognizing that every clinical situation is unique. METHODS: The methodology utilized included the development of objectives and key questions. The methodology also utilized trustworthy standards, appropriate disclosures of conflicts of interest, as well as a panel of experts from various specialties and groups. The literature pertaining to opioid use, abuse, effectiveness, and adverse consequences was reviewed, with a best evidence synthesis of the available literature, and utilized grading for recommendation as described by the Agency for Healthcare Research and Quality (AHRQ).Summary of Recommendations:i. Initial Steps of Opioid Therapy 1. Comprehensive assessment and documentation. (Evidence: Level I; Strength of Recommendation: Strong) 2. Screening for opioid abuse to identify opioid abusers. (Evidence: Level II-III; Strength of Recommendation: Moderate) 3. Utilization of prescription drug monitoring programs (PDMPs). (Evidence: Level I-II; Strength of Recommendation: Moderate to strong) 4. Utilization of urine drug testing (UDT). (Evidence: Level II; Strength of Recommendation: Moderate) 5. Establish appropriate physical diagnosis and psychological diagnosis if available. (Evidence: Level I; Strength of Recommendation: Strong) 6. Consider appropriate imaging, physical diagnosis, and psychological status to collaborate with subjective complaints. (Evidence: Level III; Strength of Recommendation: Moderate) 7. Establish medical necessity based on average moderate to severe (>/= 4 on a scale of 0 - 10) pain and/or disability. (Evidence: Level II; Strength of Recommendation: Moderate) 8. Stratify patients based on risk. (Evidence: Level I-II; Strength of Recommendation: Moderate) 9. Establish treatment goals of opioid therapy with regard to pain relief and improvement in function. (Evidence: Level I-II; Strength of Recommendation: Moderate) 10. Obtain a robust opioid agreement, which is followed by all parties. (Evidence: Level III; Strength of Recommendation: Moderate)ii. Assessment of Effectiveness of Long-Term Opioid Therapy 11. Initiate opioid therapy with low dose, short-acting drugs, with appropriate monitoring. (Evidence: Level II; Strength of Recommendation: Moderate) 12. Consider up to 40 morphine milligram equivalent (MME) as low dose, 41 to 90 MME as a moderate dose, and greater than 91 MME as high dose. (Evidence: Level II; Strength of Recommendation: Moderate) 13. Avoid long-acting opioids for the initiation of opioid therapy. (Evidence: Level I; Strength of Recommendation: Strong) 14. Recommend methadone only for use after failure of other opioid therapy and only by clinicians with specific training in its risks and uses, within FDA recommended doses. (Evidence: Level I; Strength of Recommendation: Strong) 15. Understand and educate the patients of the effectiveness and adverse consequences. (Evidence: Level I; Strength of Recommendation: Strong) 16. Similar effectiveness for long-acting and short-acting opioids with increased adverse consequences of long-acting opioids. (Evidence: Level I-II; Strength of recommendation: Moderate to strong) 17. Periodically assess pain relief and/or functional status improvement of >/= 30% without adverse consequences. (Evidence: Level II; Strength of recommendation: Moderate) 18. Recommend long-acting or high dose opioids only in specific circumstances with severe intractable pain. (Evidence: Level I; Strength of Recommendation: Strong)iii. Monitoring for Adherence and Side Effects 19. Monitor for adherence, abuse, and noncompliance by UDT and PDMPs. (Evidence: Level I-II; Strength of Recommendation: Moderate to strong) 20. Monitor patients on methadone with an electrocardiogram periodically. (Evidence: Level I; Strength of Recommendation: Strong). 21. Monitor for side effects including constipation and manage them appropriately, including discontinuation of opioids when indicated. (Evidence: Level I; Strength of Recommendation: Strong)iv. Final Phase 22. May continue with monitoring with continued medical necessity, with appropriate outcomes. (Evidence: Level I-II; Strength of Recommendation: Moderate) 23. Discontinue opioid therapy for lack of response, adverse consequences, and abuse with rehabilitation. (Evidence: Level III; Strength of Recommendation: Moderate) CONCLUSIONS: These guidelines were developed based on comprehensive review of the literature, consensus among the panelists, in consonance with patient preferences, shared decision-making, and practice patterns with limited evidence, based on randomized controlled trials (RCTs) to improve pain and function in chronic non-cancer pain on a long-term basis. Consequently, chronic opioid therapy should be provided only to patients with proven medical necessity and stability with improvement in pain and function, independently or in conjunction with other modalities of treatments in low doses with appropriate adherence monitoring and understanding of adverse events.Key words: Chronic pain, persistent pain, non-cancer pain, controlled substances, substance abuse, prescription drug abuse, dependency, opioids, prescription monitoring, drug testing, adherence monitoring, diversionDisclaimer: The guidelines are based on the best available evidence and do not constitute inflexible treatment recommendations. Due to the changing body of evidence, this document is not intended to be a "standard of care."