Birds of a Feather Redux: Defining Ways to Stimulate the Peripheral Nervous System.

Peripheral nerve stimulation (PNS) has become an essential component in the pain management plan for individuals suffering from peripheral nerve-mediated pain. The recent surge in interest in PNS can be attributed to the advancements in imaging techniques and the availability of minimally invasive stimulation systems along with a deeper grasp of PNS physiology. These advancements have made PNS more accessible to clinicians and patients alike. However, it is important to note that PNS requires a different set of technical requirements and skills compared to other pain management procedures. The work, knowledge, and surgical and interventional skillset required for PNS are in a class of their own. This article aims to educate and clarify the differences between procedures that may have similar names but are vastly different in terms of technology, expertise, and skill sets necessary for their safe implementation. Some of the procedures that this article will cover include indirect peripheral nerve field stimulation (PNfS), indirect percutaneous electrical nerve stimulation (PENS), PENS-Field Stimulation (PENFS), and transcutaneous electrical nerve stimulation (TENS). By understanding the differences between these procedures, patients and health-care providers can make informed decisions about the best approach for managing pain.

Multidisciplinary simulation of local anaesthetic systemic toxicity improves diagnostic and treatment skills and self-confidence for pain clinic procedural staff.

Local anaesthetic systemic toxicity (LAST) is a rare complication after outpatient interventional pain procedures, which can present as an emergent and life-threatening condition. Proficiency and confidence in managing this rare situation necessitates strategies to ensure team members can perform necessary tasks. The primary objective was to familiarse the pain clinic procedural staff-physicians, nurses, medical assistants, and radiation technologists-with concise and current instruction and an opportunity to practice in a controlled environment. A two-part series was designed and led by the pain physicians, with the assistance of the simulation centre and clinic staff. A 20 min didactic session was held to familiarise the providers with relevant details and information regarding LAST. Then, 2 weeks later, all team members participated in a simulation exercise intended to portray a LAST encounter, tasking participants to recognise and manage the condition in a team-based model. Before and after the didactic and simulation sessions, the staff was administered a questionnaire to assess knowledge of LAST signs, symptoms, management strategies, and priorities. Respondents were better able to identify signs and symptoms of toxicity and prioritise management steps, and felt more confident in recognising symptoms, starting treatment and coordinating care. Furthermore, participants emphasised the positive of debriefing, practicing a rare situation and learning strategies for effective communication, team dynamics and role clarity. FORMAT: Small group didactic session, simulation exercise in a clinical simulation lab. TARGET AUDIENCE: Attending, fellow, and resident physicians, medical students, registered nurses, certified medical assistants, and radiation technologists working in a pain clinic procedure suite. OBJECTIVES: To acquaint the pain clinic procedural staff with current training related to LAST and an opportunity to practice in a controlled environment.

Telemedicine Implementation in Pain Medicine: A Survey Evaluation of Pain Medicine Practices in Spring 2020.

BACKGROUND: The COVID-19 pandemic resulted in a novel challenge for healthcare delivery and implementation in the United States (US) in 2020 and beyond. Telemedicine arose as a significant and effective medium for safe and efficacious physician-patient interactions. Prior to the COVID-19 pandemic, telemedicine while available, had infrequently been utilized in pain medicine practices due to difficulties with reimbursement, the learning curve associated with new technology usage, and the need for new logistical systems in place to implement telemedicine effectively. Given the unique constraints on the healthcare system during the COVID-19 pandemic, the ubiquitous utilization of telemedicine among pain medicine physicians increased, giving insight into potential future roles for the technology beyond the pandemic. OBJECTIVES: To survey and understand the state of implementation of telemedicine into pain medicine practices across practice settings and geographical areas; to identify potential barriers to the implementation of telemedicine in pain medicine practice; and to identify the likelihood of telemedicine continuing beyond the pandemic in pain medicine practice. STUDY DESIGN: Online questionnaire targeting Pain Medicine physicians in the US. Participants were asked questions related to the use of telemedicine during the first peak of the COVID-19 pandemic. SETTING: Online-based questionnaire distributed to academic and private practice pain medicine physicians nationally in the United States. METHODS: A 34 web-based questionnaires were distributed by the American Society of Regional Anesthesia and Pain Medicine and the Spine Intervention Society to all active members. Data were analyzed using SAS v9.4. RESULTS: Between December 3, 2020, and February 18, 2021, 164 participants accessed the survey with a response rate of 14.3%. Overall, academic physicians were more likely to implement telemedicine than private practice physicians. Telemedicine was also more frequently utilized for follow-up appointments rather than initial visits. LIMITATIONS: Although our n = 164, the overall low response rate of 14.3% warrants further investigation into the utilization of telemedicine throughout the COVID-19 pandemic. CONCLUSIONS: Telemedicine as an emerging technology for efficient communication played a key role in mitigating the adverse effects of the COVID -19 pandemic on chronic pain patients. The utilization of telemedicine remarkably increased after the start of the pandemic within 1 to 2 weeks. Overall, private hospital-based centers were significantly less likely to implement telemedicine than academic centers, possibly due to limited access to secure telemedicine platforms and high start-up costs. Telemedicine was used more frequently for follow-up visits than initial visit encounters at most centers. In spite of the unforeseen consequences to the healthcare system and chronic pain practices in the US from COVID-19, telehealth has emerged as a unique model of care for patients with chronic pain. Although it has flaws, telehealth has the ability to increase access to care beyond the end of the pandemic. Further identification of barriers to the use of telemedicine platforms in private practices should be addressed from a policy perspective to facilitate increased care access.

Challenges in Utilizing Telehealth for Chronic Pain.

PURPOSE OF REVIEW: Chronic pain in the USA has presented with higher prevalence rates among women, older adults, those unemployed, living in poverty, living in rural environments, and adults with public health insurance. The COVID-19 pandemic has heavily played into the biopsychosocial model of pain. Consequently, greater impacts have affected patients with mood disorders, opioid abuse, and chronic pain. Concurrently, telemedicine has become a popular vehicle during the COVID-19 pandemic in continuing to provide quality patient care. The purpose of this article is to review the benefits and challenges related to the delivery of telemedicine for patients with chronic pain. RECENT FINDINGS: The benefits of telemedicine have been examined from patient psychosocial and convenience factors as well in relation to medical practice efficiency. Within chronic pain management, one of telemedicine's most effective utilization is seen via post-injection follow-up and assessment of further necessary interventions. Challenges also exist in this framework, from lack of physical examination and convenient close therapeutic monitoring and drug screening, to technological and resource cost capabilities of older and disadvantaged chronic pain patients, to barriers in establishing patient-provider rapport. During the COVID-19 pandemic, telehealth services were covered at rates comparable to in-person visits. Health insurance coverage and payment were major barriers for implementation of telemedicine prior to the pandemic. It is difficult to predict ongoing coverage and payment of telehealth services, although the benefits in terms of access and patient satisfaction have clearly been demonstrated. While telemedicine has proven to be a very useful tool with a wealth of advantages, the delivery of virtual healthcare for chronic pain poses a set of challenges that will need to be met to ensure the quality and standard of care continue to be upheld.

Sympathetic Blocks for Visceral Pain.

For patients with chronic pain or cancer-related pain, the most common indication for sympathetic block is to control visceral pain arising from malignancies or other alterations of the abdominal and pelvic viscera. When it is recalcitrant to conservative care, or if the patient is intolerant to pharmacotherapy, consideration of sympathetic blocks or neurolytic procedures is considered. Potential advantages of a neurolytic procedure, compared with spinal and epidural anesthetic infusions, include cost savings and avoidance of hardware. Interventional therapies that target afferent visceral innervation via the sympathetic ganglia offer effective and durable analgesia and improve multiple metrics of quality of life.

An evidence-based review of CGRP mechanisms in the propagation of chronic visceral pain.

Chronic pain is typically defined as pain that persists after acute tissue damage and inflammation or as pain that follows a chronic disease process and lasts more than three months. Because of its debilitating impact on the quality of life of patients, recent research aims to investigate the mechanisms behind nociception to discover novel therapeutic agents to alleviate pain. One such target is the neuropeptide calcitonin gene-related peptide (CGRP), which has shown to play an integral role in migraine pathophysiology. Effective treatments of migraines with CGRP antagonists have stimulated our efforts toward checking a possible involvement of CGRP in nonheadache pain conditions such as hypertension, congestive heart failure, Alzheimer's disease, and vascular ischemia. Here, we provide a brief overview of chronic pain, with a particular emphasis on the role of CGRP as a fundamental mediator of nociceptive pain as well as a target for novel therapeutic agents.

Treatment of Chronic Abdominal Pain With 10-kHz Spinal Cord Stimulation: Safety and Efficacy Results From a 12-Month Prospective, Multicenter, Feasibility Study.

INTRODUCTION: Chronic abdominal pain (CAP) can arise from multiple conditions, including inflammatory disorders, trauma because of injury or surgery, or structural or functional causes. This prospective, single-arm study was designed to evaluate the safety and efficacy of 10-kHz spinal cord stimulation (SCS) in patients with intractable CAP over a 12-month follow-up period. METHODS: Subjects with CAP who had been refractory to conventional medical treatment for at least 3 months resulting in self-reported pain scores of ≥5 cm on a 10-cm visual analog scale were enrolled at 4 centers in the United States. Study subjects underwent a trial stimulation lasting up to 14 days with epidural leads implanted from the vertebral levels T4 through T8. Subjects who had ≥40% pain relief during the trial stimulation period were implanted with a Senza system (Nevro Corp., Redwood City, CA) and followed up to 12 months after surgery. RESULTS: Twenty-three of 24 subjects (95.8%) had a successful trial stimulation and proceeded to a permanent implant. After 12 months of treatment with 10-kHz SCS, 78.3% of subjects were responders (pain relief of ≥50%) and 14 of 22 subjects (63.6%) were remitters (sustained ≤3.0-cm visual analog scale scores). Secondary outcomes, including assessments of disability, mental and physical well-being, sleep quality, perception of improvement, and satisfaction, showed that 10-kHz SCS greatly improved the quality of life of patients with CAP. Observationally, most subjects also reported concurrent reduction or resolution of nausea and/or vomiting. DISCUSSION: 10-kHz SCS can provide durable pain relief and improve the quality of life in patients with CAP.

Consensus practice guidelines on interventions for lumbar facet joint pain from a multispecialty, international working group.

BACKGROUND: The past two decades have witnessed a surge in the use of lumbar facet blocks and radiofrequency ablation (RFA) to treat low back pain (LBP), yet nearly all aspects of the procedures remain controversial. METHODS: After approval by the Board of Directors of the American Society of Regional Anesthesia and Pain Medicine, letters were sent to a dozen pain societies, as well as representatives from the US Departments of Veterans Affairs and Defense. A steering committee was convened to select preliminary questions, which were revised by the full committee. Questions were assigned to 4-5 person modules, who worked with the Subcommittee Lead and Committee Chair on preliminary versions, which were sent to the full committee. We used a modified Delphi method, whereby the questions were sent to the committee en bloc and comments were returned in a non-blinded fashion to the Chair, who incorporated the comments and sent out revised versions until consensus was reached. RESULTS: 17 questions were selected for guideline development, with 100% consensus achieved by committee members on all topics. All societies except for one approved every recommendation, with one society dissenting on two questions (number of blocks and cut-off for a positive block before RFA), but approving the document. Specific questions that were addressed included the value of history and physical examination in selecting patients for blocks, the value of imaging in patient selection, whether conservative treatment should be used before injections, whether imaging is necessary for block performance, the diagnostic and prognostic value of medial branch blocks (MBB) and intra-articular (IA) injections, the effects of sedation and injectate volume on validity, whether facet blocks have therapeutic value, what the ideal cut-off value is for a prognostic block, how many blocks should be performed before RFA, how electrodes should be oriented, the evidence for larger lesions, whether stimulation should be used before RFA, ways to mitigate complications, if different standards should be applied to clinical practice and clinical trials and the evidence for repeating RFA (see table 12 for summary). CONCLUSIONS: Lumbar medial branch RFA may provide benefit to well-selected individuals, with MBB being more predictive than IA injections. More stringent selection criteria are likely to improve denervation outcomes, but at the expense of more false-negatives. Clinical trials should be tailored based on objectives, and selection criteria for some may be more stringent than what is ideal in clinical practice.

Postoperative oxycodone toxicity in a patient with chronic pain and end-stage renal disease.

We present this case to review the metabolism of oxycodone and the effects of end-stage renal disease on the elimination of oxycodone and its metabolites. A 42-year-old female with end-stage renal disease who was dependent on hemodialysis presented for left hamstring posterior capsule release. She had been receiving methadone for 2 years for chronic leg pain. On postoperative day 1, the patient's medication was changed from IV hydromorphone to oral oxycodone to treat breakthrough pain. By the next day, the patient was unarousable with notable respiratory depression. She did not fully recover after urgent hemodialysis but did have full recovery after receiving an IV naloxone infusion for 22 hours. Further study of the safety of oxycodone in hemodialysis patients is warranted.

Safeguards to prevent neurologic complications after epidural steroid injections: consensus opinions from a multidisciplinary working group and national organizations.

BACKGROUND: Epidural corticosteroid injections are a common treatment for radicular pain caused by intervertebral disc herniations, spinal stenosis, and other disorders. Although rare, catastrophic neurologic injuries, including stroke and spinal cord injury, have occurred with these injections. METHODS: A collaboration was undertaken between the U.S. Food and Drug Administration Safe Use Initiative, an expert multidisciplinary working group, and 13 specialty stakeholder societies. The goal of this collaboration was to review the existing evidence regarding neurologic complications associated with epidural corticosteroid injections and produce consensus procedural clinical considerations aimed at enhancing the safety of these injections. U.S. Food and Drug Administration Safe Use Initiative representatives helped convene and facilitate meetings without actively participating in the deliberations or decision-making process. RESULTS: Seventeen clinical considerations aimed at improving safety were produced by the stakeholder societies. Specific clinical considerations for performing transforaminal and interlaminar injections, including the use of nonparticulate steroid, anatomic considerations, and use of radiographic guidance are given along with the existing scientific evidence for each clinical consideration. CONCLUSION: Adherence to specific recommended practices when performing epidural corticosteroid injections should lead to a reduction in the incidence of neurologic injuries.

Sacroiliac joint radiofrequency ablation with a multilesion probe: a case series of 60 patients.

This retrospective case series of patients with refractory sacroiliac joint (SIJ) pain presents our first 77 SIJ radiofrequency ablation (RFA) procedures performed with a multilesion probe. Of these, 16 (20.8%) provided no relief; 55 (71.4%) provided >50% pain relief at 6 weeks; 42 (54.5%, 95% confidence interval, 42.8%-65.8%) provided >50% pain relief at 6 months; and 12 (15.6%) continued to provide >50% pain relief at 1 year. These results compare favorably to those published using other RFA techniques. In conclusion, more than half of our patients with refractory SIJ pain received some pain relief for at least 6 months after RFA.

Interventional procedures for facial pain.

Interventional pain procedures are critical in the diagnosis and management of a variety of facial pain conditions. Trigeminal neuralgia (TN) is the most frequent diagnosis for facial pain, with a reported prevalence 10 times greater than persistent idiopathic facial pain (PIFP). Although pharmacological treatments and psychological interventions benefit many patients with these diagnoses, the pain remains disabling for a significant portion of others. Percutaneous interventions targeting the gasserian ganglion and its branches have proven effective in the management of TN, while there is also supportive evidence for treating the sphenopalatine ganglion in PIFP.

Beyond opioid patient-controlled analgesia: a systematic review of analgesia after major spine surgery.

Postoperative pain control in patients undergoing spine surgery remains a challenge for the anesthesiologist. In addition to incisional pain, these patients experience pain arising from deeper tissues such as bones, ligaments, muscles, intervertebral disks, facet joints, and damaged nerve roots. The pain from these structures may be more severe and can lead to neural sensitization and release of mediators both peripherally and centrally. The problem is compounded by the fact that many of these patients are either opioid dependent or opioid tolerant, making them less responsive to the most commonly used therapy for postoperative pain (opioid-based intermittent or patient-controlled analgesia). The purpose of this review was to compare all published treatment options available that go beyond intravenous opiates and attempt to find the best possible treatment modality.

Spontaneous resolution of nausea induced by spinal cord stimulation for failed back surgery syndrome.

INTRODUCTION: Spinal cord stimulation (SCS) is used for treatment of pain arising from a variety of pathologies. Reported side-effects related to SCS are most commonly technical complications including malfunction, lead migration, or severance. Up to date, only a few cases of gastrointestinal side-effects have been reported. MATERIALS AND METHODS: A 54-year-old man with a 20-year history of low back pain developed persistent and refractory nausea following spinal cord stimulator implantation. RESULTS: The nausea resolved spontaneously within eight weeks allowing continued use of the spinal cord stimulator. CONCLUSIONS: In this case report, we described the uncommon side-effect of nausea because of SCS that resolved over time allowing continued neurostimulation therapy in a patient with arachnoiditis and failed lumbar back surgery syndrome. We encourage other providers to report similar cases to help elucidate the mechanism of these seemingly underreported side-effects to allow continuation of the therapeutic effects of SCS.