The Polyanalgesic Consensus Conference (PACC): Recommendations on Intrathecal Drug Infusion Systems Best Practices and Guidelines.

INTRODUCTION: Pain treatment is best performed when a patient-centric, safety-based philosophy is used to determine an algorithmic process to guide care. Since 2007, the International Neuromodulation Society has organized a group of experts to evaluate evidence and create a Polyanalgesic Consensus Conference (PACC) to guide practice. METHODS: The current PACC update was designed to address the deficiencies and innovations emerging since the previous PACC publication of 2012. An extensive literature search identified publications between January 15, 2007 and November 22, 2015 and authors contributed additional relevant sources. After reviewing the literature, the panel convened to determine evidence levels and degrees of recommendations for intrathecal therapy. This meeting served as the basis for consensus development, which was ranked as strong, moderate or weak. Algorithms were developed for intrathecal medication choices to treat nociceptive and neuropathic pain for patients with cancer, terminal illness, and noncancer pain, with either localized or diffuse pain. RESULTS: The PACC has developed an algorithmic process for several aspects of intrathecal drug delivery to promote safe and efficacious evidence-based care. Consensus opinion, based on expertise, was used to fill gaps in evidence. Thirty-one consensus points emerged from the panel considerations. CONCLUSION: New algorithms and guidance have been established to improve care with the use of intrathecal drug delivery.

The Polyanalgesic Consensus Conference (PACC): Recommendations for Intrathecal Drug Delivery: Guidance for Improving Safety and Mitigating Risks.

INTRODUCTION: Intrathecal therapy is an important part of the pain treatment algorithm for chronic disease states. The use of this option is a viable treatment strategy, but it is inherent for pain physicians to understand risk assessment and mitigation. In this manuscript, we explore evidence and mitigating strategies to improve safety with intrathecal therapy. METHODS: A robust literature search was performed covering January 2011 to October 9, 2016, in PubMed, Embase, MEDLINE, Biomed Central, Google Scholar, Current Contents Connect, and International Pharmaceutical Abstracts. The information was cross-referenced and compiled for evidence, analysis, and consensus review, with the intent to offer weighted recommendations and consensus statements on safety for targeted intrathecal therapy delivery. RESULTS: The Polyanalgesic Consensus Conference has made several best practice recommendations to improve care and reduce morbidity and mortality associated with intrathecal therapy through all phases of management. The United States Prevention Service Task Force evidence level and consensus strength assessments are offered for each recommendation. CONCLUSION: Intrathecal therapy is a viable and relatively safe option for the treatment of cancer- and noncancer-related pain. Continued research and expert opinion are required to improve our current pharmacokinetic and pharmacodynamic model of intrathecal drug delivery, as this will undoubtedly improve safety and efficacy.

The appropriate use of neurostimulation of the spinal cord and peripheral nervous system for the treatment of chronic pain and ischemic diseases: the Neuromodulation Appropriateness Consensus Committee.

INTRODUCTION: The Neuromodulation Appropriateness Consensus Committee (NACC) of the International Neuromodulation Society (INS) evaluated evidence regarding the safety and efficacy of neurostimulation to treat chronic pain, chronic critical limb ischemia, and refractory angina and recommended appropriate clinical applications. METHODS: The NACC used literature reviews, expert opinion, clinical experience, and individual research. Authors consulted the Practice Parameters for the Use of Spinal Cord Stimulation in the Treatment of Neuropathic Pain (2006), systematic reviews (1984 to 2013), and prospective and randomized controlled trials (2005 to 2013) identified through PubMed, EMBASE, and Google Scholar. RESULTS: Neurostimulation is relatively safe because of its minimally invasive and reversible characteristics. Comparison with medical management is difficult, as patients considered for neurostimulation have failed conservative management. Unlike alternative therapies, neurostimulation is not associated with medication-related side effects and has enduring effect. Device-related complications are not uncommon; however, the incidence is becoming less frequent as technology progresses and surgical skills improve. Randomized controlled studies support the efficacy of spinal cord stimulation in treating failed back surgery syndrome and complex regional pain syndrome. Similar studies of neurostimulation for peripheral neuropathic pain, postamputation pain, postherpetic neuralgia, and other causes of nerve injury are needed. International guidelines recommend spinal cord stimulation to treat refractory angina; other indications, such as congestive heart failure, are being investigated. CONCLUSIONS: Appropriate neurostimulation is safe and effective in some chronic pain conditions. Technological refinements and clinical evidence will continue to expand its use. The NACC seeks to facilitate the efficacy and safety of neurostimulation.

Polyanalgesic Consensus Conference--2012: recommendations to reduce morbidity and mortality in intrathecal drug delivery in the treatment of chronic pain.

INTRODUCTION: Targeted intrathecal drug infusion to treat moderate to severe chronic pain has become a standard part of treatment algorithms when more conservative options fail. This therapy is well established in the literature, has shown efficacy, and is an important tool for the treatment of both cancer and noncancer pain; however, it has become clear in recent years that intrathecal drug delivery is associated with risks for serious morbidity and mortality. METHODS: The Polyanalgesic Consensus Conference is a meeting of experienced implanting physicians who strive to improve care in those receiving implantable devices. Employing data generated through an extensive literature search combined with clinical experience, this work group formulated recommendations regarding awareness, education, and mitigation of the morbidity and mortality associated with intrathecal therapy to establish best practices for targeted intrathecal drug delivery systems. RESULTS: Best practices for improved patient care and outcomes with targeted intrathecal infusion are recommended to minimize the risk of morbidity and mortality. Areas of focus include respiratory depression, infection, granuloma, device-related complications, endocrinopathies, and human error. Specific guidance is given with each of these issues and the general use of the therapy. CONCLUSIONS: Targeted intrathecal drug delivery systems are associated with risks for morbidity and mortality that can be devastating. The panel has given guidance to treating physicians and healthcare providers to reduce the incidence of these problems and to improve outcomes when problems occur.

Polyanalgesic Consensus Conference--2012: consensus on diagnosis, detection, and treatment of catheter-tip granulomas (inflammatory masses).

INTRODUCTION: Continuous intrathecal infusion of drugs to treat chronic pain and spasticity has become a standard part of the algorithm of care. The use of opioids has been associated with noninfectious inflammatory masses at the tip of the intrathecal catheter, which can result in neurologic complications. METHODS: The Polyanalgesic Consensus Conference is a meeting of a group of well-published and experienced practitioners; the purpose of the meeting is to update the standard of care for intrathecal therapies to reflect current knowledge gleaned from literature and clinical experience. An exhaustive literature search was performed, and information from this search was provided to panel members. Analysis of the published literature was coupled with the clinical experience of panel participants to form recommendations regarding intrathecal inflammatory masses or granulomas. RESULTS: The panel has made recommendations for the prevention, diagnosis, and management of intrathecal granulomas. CONCLUSION: The use of chronic infusions of intrathecal opioids is associated with the formation of inflammatory masses at the intrathecal catheter tip in a small minority of treated patients. Nonetheless, the appearance of these space-occupying lesions can lead to devastating neurologic sequelae. The prevention, early detection, and successful treatment of intraspinal granulomas are important considerations when offering intrathecal drug therapy to patients with chronic intractable pain.

Practice choices and challenges in the current intrathecal therapy environment: an online survey.

OBJECTIVE: The objective of this study was to evaluate current practice characteristics, treatment choices, clinical experiences, and economic concerns associated with intrathecal therapy. DESIGN: Health care professionals in the United States, who were known to actively use intrathecal therapy in their practices, were recruited to participate in an online survey; contact information was obtained via Internet searches, university Websites, association memberships, industry databases, and personal contacts. Survey responses were summarized descriptively. RESULTS: Of the 329 practitioners who were contacted, 87 participated in the survey. Most participants specialized in anesthesiology (77.0%), worked in a private practice or private hospital (74.7%), and had been practicing pain management for more than 10 years (64.4%). Morphine was the most frequently used opioid for the initiation of intrathecal therapy (80.7% of practitioners), and 81.9% had used ziconotide in their practice. Most practitioners (63.9%) had treated at least one patient who developed a granuloma, and 66.0% of those practitioners had a patient experience permanent or temporary neurological injury due to a granuloma. Fewer than half of practitioners were satisfied with reimbursement from private insurance companies (25.3%) or workers compensation (34.9%), and 90.5% believed reimbursement rates for filling, refilling, and programming patient pumps are not adequate to cover practice costs. The majority of practitioners (56.6%) use fewer pumps in their practices because of reimbursement issues. CONCLUSIONS: Intrathecal pain management practices continue to evolve as the options for treatment increase, and the body of applicable scientific literature grows; however, economic considerations can influence clinical decisions and may interfere with treatment choice and patient access to therapy.

Management of intrathecal catheter-tip inflammatory masses: an updated 2007 consensus statement from an expert panel.

Background. Expert panel of physicians and nonphysicians, all expert in intrathecal (IT) therapies, convened in the years 2000 and 2003 to make recommendations for the rational use of IT analgesics based on the preclinical and clinical literature known up to those times, presentations of the expert panel, discussions on current practice and standards, and the result of surveys of physicians using IT agents. An expert panel of physicians and convened in 2007 to review previous recommendations and to form recommendations for the rational use of IT agents as they pertain to new scientific and clinical information regarding the etiology, prevention and treatment for IT granuloma. Method. A review of preclinical and clinical literature from 2000 to 2006 was undertaken and disseminated to an expert panel of physicians. Focused discussions concerning the rational use of IT agents and its relationship to the etiology of, prevention of, and treatment of IT granuloma were held. Results. This report presents here new knowledge of the etiology of catheter tip granuloma and guidelines for its prevention and treatment.

Future directions for intrathecal pain management: a review and update from the interdisciplinary polyanalgesic consensus conference 2007.

Background. Expert panels of physicians and nonphysicians, all expert in intrathecal (IT) therapies, convened in the years 2000 and 2003 to make recommendations for the rational use of IT analgesics, based on the preclinical and clinical literature known up to those times, presentations of the expert panels, discussions on current practice and standards, and the result of surveys of physicians using IT agents. An expert panel of physicians and nonphysicians has convened in 2007 to update information known regarding IT therapies and to update information on new and novel opioid and nonopioid analgesic compounds that might show promise for IT use. Methods. A review of preclinical and clinical published relevant studies from 2000 to 2006 was undertaken and disseminated to a convened expert panel of physicians and nonphysicians to discuss new and novel analgesic agents for IT use. Results. The panelists identified several agents that were worthy of future studies for the clinical and rational use of IT agents that are presented in this article. Conclusions. A list of nonopioid IT analgesics, including gabapentin, adenosine, octreotide, the χ-conopeptide, Xen2174, the conopeptide, neurotensis 1 agonist, CGX-1160, the ω-conotoxin, AM-336, and physostigmine, were identified as worthy of future research by the panelists.

Spinal cord stimulation has comparable efficacy in common pain etiologies.

Objectives. The probability of success with spinal cord stimulation (SCS) depends largely on appropriate patient selection. Here, we have assessed the predictive value of pain etiology as it relates to pain relief with SCS as part of a prospective multicenter clinical trial. Methods. Sixty-five subjects with chronic and intractable pain tested an epidural SCS system. Subjects reported pain ratings (visual analog scale) with stimulation off and stimulation on at scheduled follow-up visits for up to 18 months after activation of the system. Visual analog scale scores were averaged and stratified by dominant pain etiologies, comprising failed back surgery syndrome, complex regional pain syndrome, and a subgroup of subjects with miscellaneous other pain etiologies. Results. More than 70% of subjects in each subgroup had successful outcomes during the temporary trial period and similar percentages of subjects from each etiology subgroup subsequently went on to permanent implantation. After permanent implantation, all subgroups reported more than 50% pain relief, on average, at each follow-up time point. No predictive value of pain etiology was observed. Conclusions. Spinal cord stimulation is an effective therapy for neuropathic pain arising from a variety of causes. Failed back surgery syndrome, complex regional pain syndrome, and pain of other etiologies responded equally well to SCS.

Sciatica of nondisc origin and piriformis syndrome: diagnosis by magnetic resonance neurography and interventional magnetic resonance imaging with outcome study of resulting treatment.

OBJECT: Because lumbar magnetic resonance (MR) imaging fails to identify a treatable cause of chronic sciatica in nearly 1 million patients annually, the authors conducted MR neurography and interventional MR imaging in 239 consecutive patients with sciatica in whom standard diagnosis and treatment failed to effect improvement. METHODS: After performing MR neurography and interventional MR imaging, the final rediagnoses included the following: piriformis syndrome (67.8%), distal foraminal nerve root entrapment (6%), ischial tunnel syndrome (4.7%), discogenic pain with referred leg pain (3.4%), pudendal nerve entrapment with referred pain (3%), distal sciatic entrapment (2.1%), sciatic tumor (1.7%), lumbosacral plexus entrapment (1.3%), unappreciated lateral disc herniation (1.3%), nerve root injury due to spinal surgery (1.3%), inadequate spinal nerve root decompression (0.8%), lumbar stenosis (0.8%), sacroiliac joint inflammation (0.8%), lumbosacral plexus tumor (0.4%), sacral fracture (0.4%), and no diagnosis (4.2%). Open MR-guided Marcaine injection into the piriformis muscle produced the following results: no response (15.7%), relief of greater than 8 months (14.9%), relief lasting 2 to 4 months with continuing relief after second injection (7.5%), relief for 2 to 4 months with subsequent recurrence (36.6%), and relief for 1 to 14 days with full recurrence (25.4%). Piriformis surgery (62 operations; 3-cm incision, transgluteal approach, 55% outpatient; 40% with local or epidural anesthesia) resulted in excellent outcome in 58.5%, good outcome in 22.6%, limited benefit in 13.2%, no benefit in 3.8%, and worsened symptoms in 1.9%. CONCLUSIONS: This Class A quality evaluation of MR neurography's diagnostic efficacy revealed that piriformis muscle asymmetry and sciatic nerve hyperintensity at the sciatic notch exhibited a 93% specificity and 64% sensitivity in distinguishing patients with piriformis syndrome from those without who had similar symptoms (p < 0.01). Evaluation of the nerve beyond the proximal foramen provided eight additional diagnostic categories affecting 96% of these patients. More than 80% of the population good or excellent functional outcome was achieved.

Spinal cord stimulation: mechanisms of action.

STUDY DESIGN: A literature review and synthesis were performed. OBJECTIVE: To present the current understanding of the mechanisms of spinal cord stimulation in relation to the physiology of pain. SUMMARY OF BACKGROUND DATA: Spinal cord stimulation has been used for more than 30 years in the armamentarium of the interventional pain specialist to treat a variety of pain syndromes. Traditionally used for persisting leg pain after lumbar spinal surgery, it has been applied successfully in the treatment of angina pectoris, ischemic pain in the extremity, complex regional pain syndrome Types 1 and 2, and a variety of other pain states. This review presents the current status of what is known concerning how electrical stimulation of the spinal cord may achieve pain relief. METHODS: A literature review was conducted. RESULTS: The literature supports the theory that the mechanism of spinal cord stimulation cannot be completely explained by one model. It is likely that multiple mechanisms operate sequentially or simultaneously. CONCLUSION: Some clinical or experimental support can be found in the literature for 10 specific mechanisms or proposed mechanisms of spinal cord stimulation.

Neuraxial medication delivery: the development and maturity of a concept for treating chronic pain of spinal origin.

STUDY DESIGN: A literature review and synthesis were performed. OBJECTIVE: To summarize the history, use, and innovation related to neuraxial drug delivery for the treatment of intractable back pain. SUMMARY OF BACKGROUND DATA: The discovery of opioid receptors in the early 1970s provided a rational basis for the delivery of opioid drugs intraspinally. Epidural or intrathecal infusions deliver drugs directly to opioid receptors, limit systemic exposure, and by decreasing the opioid dosage required for pain relief, generally reduce side effects. The benefits of short-term spinal analgesia led to investigation of longer-term continuous subarachnoid opioid infusions for the management of both cancer pain and noncancer pain, such as that of spinal origin. RESULTS: Unique features of this article include an updated pain continuum, updated indications for intrathecal therapy, a detailed comparison of trial techniques, a detailed comparison of the advantages of different types of pumps, a synopsis of troubleshooting for inadequate efficacy, and an updated statement regarding intrathecal pumps and radiologic procedures, including MRI scanning. Some challenges remain. Large-scale well-controlled studies could answer some perplexing questions regarding efficacy in patients with noncancer or neuropathic pain. Patient selection criteria undoubtedly will be refined and validated as more patients are treated. In addition, further investigation of specifically targeted medications or drug combinations for intraspinal use could increase efficacy, reduce side effects, and expand indications. CONCLUSIONS: Intraspinal medication delivery has become an effective technique for control of intractable pain in appropriately selected patients seen by spine surgeons.