The Neurostimulation Appropriateness Consensus Committee (NACC): Recommendations for Surgical Technique for Spinal Cord Stimulation.

INTRODUCTION: The field of neurostimulation for the treatment of chronic pain is a rapidly developing area of medicine. Although neurostimulation therapies have advanced significantly as a result of technologic improvements, surgical planning, device placement, and postoperative care are of equal importance to optimize outcomes. This Neurostimulation Appropriateness Consensus Committee (NACC) project intends to provide evidence-based guidance for these often-overlooked areas of neurostimulation practice. MATERIALS AND METHODS: Authors were chosen based on their clinical expertise, familiarity with the peer-reviewed literature, research productivity, and contributions to the neuromodulation literature. Section leaders supervised literature searches of MEDLINE, BioMed Central, Current Contents Connect, Embase, International Pharmaceutical Abstracts, Web of Science, Google Scholar, and PubMed from the last NACC publication in 2017 to the present. Identified studies were graded using the United States Preventive Services Task Force criteria for evidence and certainty of net benefit. Recommendations are based on evidence strength and consensus when evidence was scant. RESULTS: This NACC project provides guidance on preoperative assessment, intraoperative techniques, and postoperative management in the form of consensus points with supportive evidence. These results are based on grade of evidence, strength of consensus, and expert opinion. CONCLUSIONS: The NACC has given guidance for a surgical plan that encompasses the patient journey from the planning stage through the surgical experience and postoperative care. The overall recommendations are designed to improve efficacy and the safety of patients undergoing these neuromodulation procedures and are intended to apply throughout the international community.

A Systematic Literature Review of Dorsal Root Ganglion Neurostimulation for the Treatment of Pain.

OBJECTIVE: To conduct a systematic literature review of dorsal root ganglion (DRG) stimulation for pain. DESIGN: Grade the evidence for DRG stimulation. METHODS: An international, interdisciplinary work group conducted a literature search for DRG stimulation. Abstracts were reviewed to select studies for grading. General inclusion criteria were prospective trials (randomized controlled trials and observational studies) that were not part of a larger or previously reported group. Excluded studies were retrospective, too small, or existed only as abstracts. Studies were graded using the modified Interventional Pain Management Techniques-Quality Appraisal of Reliability and Risk of Bias Assessment, the Cochrane Collaborations Risk of Bias assessment, and the US Preventative Services Task Force level-of-evidence criteria. RESULTS: DRG stimulation has Level II evidence (moderate) based upon one high-quality pivotal randomized controlled trial and two lower-quality studies. CONCLUSIONS: Moderate-level evidence supports DRG stimulation for treating chronic focal neuropathic pain and complex regional pain syndrome.

A Systematic Literature Review of Spine Neurostimulation Therapies for the Treatment of Pain.

OBJECTIVE: To conduct a systematic literature review of spinal cord stimulation (SCS) for pain. DESIGN: Grade the evidence for SCS. METHODS: An international, interdisciplinary work group conducted literature searches, reviewed abstracts, and selected studies for grading. Inclusion/exclusion criteria included randomized controlled trials (RCTs) of patients with intractable pain of greater than one year's duration. Full studies were graded by two independent reviewers. Excluded studies were retrospective, had small numbers of subjects, or existed only as abstracts. Studies were graded using the modified Interventional Pain Management Techniques-Quality Appraisal of Reliability and Risk of Bias Assessment, the Cochrane Collaborations Risk of Bias assessment, and the US Preventative Services Task Force level-of-evidence criteria. RESULTS: SCS has Level 1 evidence (strong) for axial back/lumbar radiculopathy or neuralgia (five high-quality RCTs) and complex regional pain syndrome (one high-quality RCT). CONCLUSIONS: High-level evidence supports SCS for treating chronic pain and complex regional pain syndrome. For patients with failed back surgery syndrome, SCS was more effective than reoperation or medical management. New stimulation waveforms and frequencies may provide a greater likelihood of pain relief compared with conventional SCS for patients with axial back pain, with or without radicular pain.

Trialing and Maintenance Dosing Using a Low-Dose Intrathecal Opioid Method for Chronic Nonmalignant Pain: A Prospective 36-Month Study.

OBJECTIVE: To evaluate low-dose intrathecal opioid trialing and maintenance with regard to analgesia and psychometric functional capacity. MATERIALS AND METHODS: Prospective cohort of subjects offered, trialed and maintained using low-dose opioid therapy via an intrathecal drug delivery system. Analgesia, measured by visual analog scale and the Global Pain Scale, and function, measured by Multidimensional Pain Inventory and Global Pain Scale, are evaluated. Population analysis by age, gender, oral opioid dose, diagnosis, and pain type is reported. RESULTS: Fifty-eight subjects enrolled in the 36-month evaluation period with mean opioid intrathecal opioid dose less than 350 µg per day of morphine equivalent utilized. Primary nociceptive pain type were associated with lower intrathecal opioid doses and improved visual analog scale pain rating and improved pain severity and interference on the Multidimensional Pain Inventory. CONCLUSIONS: This study adds to the growing body of literature suggesting that low-dose intrathecal analgesia without oral opioid supplementation can be efficacious. It appears that this approach may achieve analgesia with lower doses in those with primary nociceptive pain type.

A randomized, double-blind trial comparing continuous thoracic epidural bupivacaine with and without opioid in contrast to a continuous paravertebral infusion of bupivacaine for post-thoracotomy pain.

OBJECTIVE: To compare the results of continuous epidural bupivacaine analgesia with and without hydromorphone to continuous paravertebral analgesia with bupivcaine in patients with post-thoracotomy pain. DESIGN: A prospective, randomized, double-blinded trial. SETTING: A teaching hospital. PARTICIPANTS: Patients at a tertiary care teaching hospital undergoing throracotomy for lung cancer. INTERVENTIONS: Subjects were assigned randomly to receive a continuous thoracic epidural or paravertebral infusion. Patients in the epidural group were randomized to receive either bupivacaine alone or in combination with hydromorphone. Visual analog scores as well as incentive spirometery results were obtained before and after thoracotomy. METHODS AND MAIN RESULTS: Seventy-five consecutive patients presenting for thoracotomy were enrolled in this institutional review board-approved study. On the morning of surgery, subjects were randomized to either an epidural group receiving bupvicaine with and without hydromorphone or a paravertebral catheter-infused bupvicaine. Postoperative visual analog scores and incentive spirometry data were measured in the postanesthesia care unit, the evening of the first operative day, and daily thereafter until postoperative day 4. Analgesia on all postoperative days was superior in the thoracic epidural group receiving bupivacaine plus hydromorphone. Analgesia was similar in the epidural and continuous paravertebral groups receiving bupivacaine alone. No significant improvement was noted by combining the continuous infusion of bupivacaine via the paravertebral and epidural routes. Incentive spirometry goals were best achieved in the epidural bupivacaine and hydromorphone group and equal in the group receiving bupivacaine alone either via epidural or continuous paravertebral infusion. CONCLUSIONS: The current study provided data that fill gaps in the current literature in 3 important areas. First, this study found that thoracic epidural analgesia (TEA) with bupivacaine and a hydrophilic opioid, hydromorphone, may provide enhanced analgesia over TEA or continuous paravertebral infusion (CPI) with bupivacaine alone. Second, in the bupivacaine-alone group, the increased basal rates required to achieve analgesia resulted in hypotension more frequently than in the bupivacaine/hydromorphone combination group, underscoring the benefit of the synergistic activity. Finally, in agreement with previous retrospective studies, the current data suggest that CPI of local anesthetic appears to provide acceptable analgesia for post-thoracotomy pain.

Epidural Interventions in the Management of Chronic Spinal Pain: American Society of Interventional Pain Physicians (ASIPP) Comprehensive Evidence-Based Guidelines.

BACKGROUND: Chronic spinal pain is the most prevalent chronic disease with employment of multiple modes of interventional techniques including epidural interventions. Multiple randomized controlled trials (RCTs), observational studies, systematic reviews, and guidelines have been published. The recent review of the utilization patterns and expenditures show that there has been a decline in utilization of epidural injections with decrease in inflation adjusted costs from 2009 to 2018. The American Society of Interventional Pain Physicians (ASIPP) published guidelines for interventional techniques in 2013, and guidelines for facet joint interventions in 2020. Consequently, these guidelines have been prepared to update previously existing guidelines. OBJECTIVE: To provide evidence-based guidance in performing therapeutic epidural procedures, including caudal, interlaminar in lumbar, cervical, and thoracic spinal regions, transforaminal in lumbar spine, and percutaneous adhesiolysis in the lumbar spine. METHODS: The methodology utilized included the development of objective and key questions with utilization of trustworthy standards. The literature pertaining to all aspects of epidural interventions was viewed with best evidence synthesis of available literature and  recommendations were provided. RESULTS: In preparation of the guidelines, extensive literature review was performed. In addition to review of multiple manuscripts in reference to utilization, expenditures, anatomical and pathophysiological considerations, pharmacological and harmful effects of drugs and procedures, for evidence synthesis we have included 47 systematic reviews and 43 RCTs covering all epidural interventions to meet the objectives.The evidence recommendations are as follows: Disc herniation: Based on relevant, high-quality fluoroscopically guided epidural injections, with or without steroids, and results of previous systematic reviews, the evidence is Level I for caudal epidural injections, lumbar interlaminar epidural injections, lumbar transforaminal epidural injections, and cervical interlaminar epidural injections with strong recommendation for long-term effectiveness.The evidence for percutaneous adhesiolysis in managing disc herniation based on one high-quality, placebo-controlled RCT is Level II with moderate to strong recommendation for long-term improvement in patients nonresponsive to conservative management and fluoroscopically guided epidural injections. For thoracic disc herniation, based on one relevant, high-quality RCT of thoracic epidural with fluoroscopic guidance, with or without steroids, the evidence is Level II with moderate to strong recommendation for long-term effectiveness.Spinal stenosis: The evidence based on one high-quality RCT in each category the evidence is Level III to II for fluoroscopically guided caudal epidural injections with moderate to strong recommendation and Level II for fluoroscopically guided lumbar and cervical interlaminar epidural injections with moderate to strong recommendation for long-term effectiveness.The evidence for lumbar transforaminal epidural injections is Level IV to III with moderate recommendation with fluoroscopically guided lumbar transforaminal epidural injections for long-term improvement. The evidence for percutaneous adhesiolysis in lumbar stenosis based on relevant, moderate to high quality RCTs, observational studies, and systematic reviews is Level II with moderate to strong recommendation for long-term improvement after failure of conservative management and fluoroscopically guided epidural injections. Axial discogenic pain: The evidence for axial discogenic pain without facet joint pain or sacroiliac joint pain in the lumbar and cervical spine with fluoroscopically guided caudal, lumbar and cervical interlaminar epidural injections, based on one relevant high quality RCT in each category is Level II with moderate to strong recommendation for long-term improvement, with or without steroids. Post-surgery syndrome: The evidence for lumbar and cervical post-surgery syndrome based on one relevant, high-quality RCT with fluoroscopic guidance for caudal and cervical interlaminar epidural injections, with or without steroids, is Level II with moderate to strong recommendation for long-term improvement. For percutaneous adhesiolysis, based on multiple moderate to high-quality RCTs and systematic reviews, the evidence is Level I with strong recommendation for long-term improvement after failure of conservative management and fluoroscopically guided epidural injections. LIMITATIONS: The limitations of these guidelines include a continued paucity of high-quality studies for some techniques and various conditions including spinal stenosis, post-surgery syndrome, and discogenic pain. CONCLUSIONS: These epidural intervention guidelines including percutaneous adhesiolysis were prepared with a comprehensive review of the literature with methodologic quality assessment and determination of level of evidence with strength of recommendations.

Comprehensive Evidence-Based Guidelines for Facet Joint Interventions in the Management of Chronic Spinal Pain: American Society of Interventional Pain Physicians (ASIPP) Guidelines Facet Joint Interventions 2020 Guidelines.

BACKGROUND: Chronic axial spinal pain is one of the major causes of significant disability and health care costs, with facet joints as one of the proven causes of pain. OBJECTIVE: To provide evidence-based guidance in performing diagnostic and therapeutic facet joint interventions. METHODS: The methodology utilized included the development of objectives and key questions with utilization of trustworthy standards. The literature pertaining to all aspects of facet joint interventions, was reviewed, with a best evidence synthesis of available literature and utilizing grading for recommendations.Summary of Evidence and Recommendations:Non-interventional diagnosis: • The level of evidence is II in selecting patients for facet joint nerve blocks at least 3 months after onset and failure of conservative management, with strong strength of recommendation for physical examination and clinical assessment. • The level of evidence is IV for accurate diagnosis of facet joint pain with physical examination based on symptoms and signs, with weak strength of recommendation. Imaging: • The level of evidence is I with strong strength of recommendation, for mandatory fluoroscopic or computed tomography (CT) guidance for all facet joint interventions. • The level of evidence is III with weak strength of recommendation for single photon emission computed tomography (SPECT) . • The level of evidence is V with weak strength of recommendation for scintography, magnetic resonance imaging (MRI), and computed tomography (CT) .Interventional Diagnosis:Lumbar Spine: • The level of evidence is I to II with moderate to strong strength of recommendation for lumbar diagnostic facet joint nerve blocks. • Ten relevant diagnostic accuracy studies with 4 of 10 studies utilizing controlled comparative local anesthetics with concordant pain relief criterion standard of ≥80% were included. • The prevalence rates ranged from 27% to 40% with false-positive rates of 27% to 47%, with ≥80% pain relief.Cervical Spine: • The level of evidence is II with moderate strength of recommendation. • Ten relevant diagnostic accuracy studies, 9 of the 10 studies with either controlled comparative local anesthetic blocks or placebo controls with concordant pain relief with a criterion standard of ≥80% were included. • The prevalence and false-positive rates ranged from 29% to 60% and of 27% to 63%, with high variability. Thoracic Spine: • The level of evidence is II with moderate strength of recommendation. • Three relevant diagnostic accuracy studies, with controlled comparative local anesthetic blocks, with concordant pain relief, with a criterion standard of ≥80% were included. • The prevalence varied from 34% to 48%, whereas false-positive rates varied from 42% to 58%.Therapeutic Facet Joint Interventions: Lumbar Spine: • The level of evidence is II with moderate strength of recommendation for lumbar radiofrequency ablation with inclusion of 11 relevant randomized controlled trials (RCTs) with 2 negative studies and 4 studies with long-term improvement. • The level of evidence is II with moderate strength of recommendation for therapeutic lumbar facet joint nerve blocks with inclusion of 3 relevant randomized controlled trials, with long-term improvement. • The level of evidence is IV with weak strength of recommendation for lumbar facet joint intraarticular injections with inclusion of 9 relevant randomized controlled trials, with majority of them showing lack of effectiveness without the use of local anesthetic. Cervical Spine: • The level of evidence is II with moderate strength of recommendation for cervical radiofrequency ablation with inclusion of one randomized controlled trial with positive results and 2 observational studies with long-term improvement. • The level of evidence is II with moderate strength of recommendation for therapeutic cervical facet joint nerve blocks with inclusion of one relevant randomized controlled trial and 3 observational studies, with long-term improvement. • The level of evidence is V with weak strength of recommendation for cervical intraarticular facet joint injections with inclusion of 3 relevant randomized controlled trials, with 2 observational studies, the majority showing lack of effectiveness, whereas one study with 6-month follow-up, showed lack of long-term improvement. Thoracic Spine: • The level of evidence is III with weak to moderate strength of recommendation with emerging evidence for thoracic radiofrequency ablation with inclusion of one relevant randomized controlled trial and 3 observational studies. • The level of evidence is II with moderate strength of recommendation for thoracic therapeutic facet joint nerve blocks with inclusion of 2 randomized controlled trials and one observational study with long-term improvement. • The level of evidence is III with weak to moderate strength of recommendation for thoracic intraarticular facet joint injections with inclusion of one randomized controlled trial with 6 month follow-up, with emerging evidence. Antithrombotic Therapy: • Facet joint interventions are considered as moderate to low risk procedures; consequently, antithrombotic therapy may be continued based on overall general status. Sedation: • The level of evidence is II with moderate strength of recommendation to avoid opioid analgesics during the diagnosis with interventional techniques. • The level of evidence is II with moderate strength of recommendation that moderate sedation may be utilized for patient comfort and to control anxiety for therapeutic facet joint interventions. LIMITATIONS: The limitations of these guidelines include a paucity of high-quality studies in the majority of aspects of diagnosis and therapy. CONCLUSIONS: These facet joint intervention guidelines were prepared with a comprehensive review of the literature with methodologic quality assessment with determination of level of evidence and strength of recommendations. KEY WORDS: Chronic spinal pain, interventional techniques, diagnostic blocks, therapeutic interventions, facet joint nerve blocks, intraarticular injections, radiofrequency neurolysis.

ASIPP Guidelines for Sedation and Fasting Status of Patients Undergoing Interventional Pain Management Procedures.

Many of the patients undergoing interventional procedures have daily regimens of medications including analgesics, muscle relaxants, and other drugs that can have significant additive/synergistic effects during the perioperative period. Further, many patients also present with comorbid states, including obesity, cardiovascular, and pulmonary disease. Consequently, in the perioperative period, a significant number of patients have suffered permanent neurologic injury, hypoxic brain injury, and even death as a result of over sedation, hypoventilation, and spinal cord injury. In addition, physicians are concerned about aspiration, subsequent complications, and as a result, they ask patients to fast for several hours prior to the procedures. Based on extensive literature and consensus, a minimum fasting period is established as 2 hours before a procedure for clear liquids and 4 hours before procedure for light meals, rather than having all patients fast for 8 hours or even fasting beginning at midnight the night before the procedure. Gastrointestinal stimulants, gastric acid secretion blockers, and antacids may be used, even though not routinely recommended. Due to the nature of chronic pain and anxiety, many patients undergoing interventional techniques may require mild to moderate sedation. Deep sedation and/or general anesthesia for most interventional procedures is considered as unsafe, since the patient cannot communicate acute changes in symptoms, thus, resulting in morbidity and mortality, as well as creating compliance issues. We are adapting the published standards of the American Society of Anesthesiologists for monitoring patients under sedation, regardless of the location of the procedure, either office-based, in a surgery center, or a hospital outpatient department. These standards include monitoring of blood pressure, cardiac rhythm, temperature, pulse oximetry, and continuous quantitative end tidal CO2 monitoring. Sedation must be provided either by qualified anesthesia or non-anesthesia providers, with appropriate understanding of the medications, drug interactions, and resuscitative protocols.KEY WORDS: Guidelines, sedation, fasting status, monitoring, neurological complications.

Responsible, Safe, and Effective Use of Antithrombotics and Anticoagulants in Patients Undergoing Interventional Techniques: American Society of Interventional Pain Physicians (ASIPP) Guidelines.

BACKGROUND: Interventional pain management involves diagnosis and treatment of chronic pain. This specialty utilizes minimally invasive procedures to target therapeutics to the central nervous system and the spinal column. A subset of patients encountered in interventional pain are medicated using anticoagulant or antithrombotic drugs to mitigate thrombosis risk. Since these drugs target the clotting system, bleeding risk is a consideration accompanying interventional procedures. Importantly, discontinuation of anticoagulant or antithrombotic drugs exposes underlying thrombosis risk, which can lead to significant morbidity and mortality especially in those with coronary artery or cerebrovascular disease. This review summarizes the literature and provides guidelines based on best evidence for patients receiving anti-clotting therapy during interventional pain procedures. STUDY DESIGN: Best evidence synthesis. OBJECTIVE: To provide a current and concise appraisal of the literature regarding an assessment of the bleeding risk during interventional techniques for patients taking anticoagulant and/or antithrombotic medications. METHODS: A review of the available literature published on bleeding risk during interventional pain procedures, practice patterns and perioperative management of anticoagulant and antithrombotic therapy was conducted. Data sources included relevant literature identified through searches of EMBASE and PubMed from 1966 through August 2018 and manual searches of the bibliographies of known primary and review articles. RESULTS: 1. There is good evidence for risk stratification by categorizing multiple interventional techniques into low-risk, moderate-risk, and high-risk. Also, their risk should be upgraded based on other risk factors.2. There is good evidence for the risk of thromboembolic events in patients who interrupt antithrombotic therapy. 3. There is good evidence supporting discontinuation of low dose aspirin for high risk and moderate risk procedures for at least 3 days, and there is moderate evidence that these may be continued for low risk or some intermediate risk procedures.4. There is good evidence that discontinuation of anticoagulant therapy with warfarin, heparin, dabigatran (Pradaxa®), argatroban (Acova®), bivalirudin (Angiomax®), lepirudin (Refludan®), desirudin (Iprivask®), hirudin, apixaban (Eliquis®), rivaroxaban (Xarelto®), edoxaban (Savaysa®, Lixiana®), Betrixaban(Bevyxxa®), fondaparinux (Arixtra®) prior to interventional techniques with individual consideration of pharmacokinetics and pharmacodynamics of the drugs and individual risk factors increases safety.5. There is good evidence that diagnosis of epidural hematoma is based on severe pain at the site of the injection, rapid neurological deterioration, and MRI with surgical decompression with progressive neurological dysfunction to avoid neurological sequelae.6. There is good evidence that if thromboembolic risk is high, low molecular weight heparin bridge therapy can be instituted during cessation of the anticoagulant, and the low molecular weight heparin can be discontinued 24 hours before the pain procedure.7. There is fair evidence that the risk of thromboembolic events is higher than that of epidural hematoma formation with the interruption of antiplatelet therapy preceding interventional techniques, though both risks are significant.8. There is fair evidence that multiple variables including anatomic pathology with spinal stenosis and ankylosing spondylitis; high risk procedures and moderate risk procedures combined with anatomic risk factors; bleeding observed during the procedure, and multiple attempts during the procedures increase the risk for bleeding complications and epidural hematoma.9. There is fair evidence that discontinuation of phosphodiesterase inhibitors is optional (dipyridamole [Persantine], cilostazol [Pletal]. However, there is also fair evidence to discontinue Aggrenox [dipyridamole plus aspirin]) 3 days prior to undergoing interventional techniques of moderate and high risk. 10. There is fair evidence to make shared decision making between the patient and the treating physicians with the treating physician and to consider all the appropriate risks associated with continuation or discontinuation of antithrombotic or anticoagulant therapy.11. There is fair evidence that if thromboembolic risk is high antithrombotic therapy may be resumed 12 hours after the interventional procedure is performed.12. There is limited evidence that discontinuation of antiplatelet therapy (clopidogrel [Plavix®], ticlopidine [Ticlid®], Ticagrelor [Brilinta®] and prasugrel [Effient®]) avoids complications of significant bleeding and epidural hematomas.13. There is very limited evidence supporting the continuation or discontinuation of most NSAIDs, excluding aspirin, for 1 to 2 days and some 4 to 10 days, since these are utilized for pain management without cardiac or cerebral protective effect. LIMITATIONS: The continued paucity of the literature with discordant recommendations. CONCLUSION: Based on the survey of current literature, and published clinical guidelines, recommendations for patients presenting with ongoing antithrombotic therapy prior to interventional techniques are variable, and are based on comprehensive analysis of each patient and the risk-benefit analysis of intervention. KEY WORDS: Perioperative bleeding, bleeding risk, practice patterns, anticoagulant therapy, antithrombotic therapy, interventional techniques, safety precautions, pain.

Anesthetic Considerations and Perioperative Management of Spinal Cord Stimulators: Literature Review and Initial Recommendations.

BACKGROUND: Patients with implanted spinal cord stimulators (SCS) present to the anesthesia care team for management at many different points along the care continuum. Currently, the literature is sparse on the perioperative management. What is available is confusing; monopolar electrocautery is contraindicated but often used, full body magnetic resonance imaging (MRI) is safe with particular systems but with other manufactures only head and specific extremities exams are safe. Moreover, there are anesthetizing locations outside of the operating room where implanted SCS can interact with surrounding medical equipment and pose significant risk to patient and device. OBJECTIVES: The objective of this review is to present relevant known literature about the safe management of SCS in the perioperative period and to begin to develop recommendations. STUDY DESIGN: A review of current literature and each manufacturers' labeling was performed to assess risk of interference and patient harm between SCS and technology used in and around typical anesthetizing locations. METHODS: A systematic search of the literature was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. A computerized search was conducted for English articles in print up to April 2016 via PubMed www.ncbi.nlm.nih.gov/pubmed; EMBASE www.embase.com; and Cochrane Library www.thecochranelibrary.com. Search terms included "spinal cord stimulator AND MRI," "spinal cord stimulator AND ECG," "spinal cord stimulator AND implanted cardiac device," "spinal cord stimulator AND electrocautery," and "spinal cord stimulator AND obstetrics." In addition, a search of Google and Google Scholar was performed. Websites of SCS manufactures were reviewed. RESULTS: Generalized recommendations include turning the amplitude of the SCS to the lowest possible SETTING and turning off prior to any procedure. Monopolar electrocautery is contraindicated but is still often utilized; placing grounding pads as far away from the device can reduce the risk to device and patient. Bipolar cautery is favored. Implanted cardiac devices can interfere with SCS, but risks can be minimized. Neuraxial anesthesia can be attempted in a patient with implanted SCS, provided the device is not in the expected path. MRI labeling differences present the biggest difference among SCS manufactures. Medtronic's SureScan SCS, Boston Scientific's Precision system, St. Jude's Proclaim, and Stimwave's Freedome SCS are full body MRI compatible under specific conditions, while other manufacturers have labeling that restricts exams of the trunk and certain extremities. LIMITATIONS: This review was intended to be a comprehensive, cumulative review of recommendations for perioperative SCS management; however, the limitations of a review of this nature is the complete reliance on previously published research and the availability of these studies using the methods outlined. CONCLUSIONS: SCS is being used earlier in the treatment algorithm for patients with chronic pain. The anesthesia care team needs working knowledge of where the device resides in the neuraxial space and what risks different medical technologies pose to the patient and device. This understanding will lead to appropriate perioperative management which can reduce risk and improve patient outcomes.

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."

Protection by GDNF and other trophic factors against the dopamine-depleting effects of neurotoxic doses of methamphetamine.

Repeated methamphetamine (METH) administration to animals can result in long-lasting decreases in striatal dopamine (DA) content. It has previously been shown that glial cell line-derived neurotrophic factor (GDNF) can reduce the DA-depleting effects of neurotoxic doses of METH. However, there are several other trophic factors that are protective against dopaminergic toxins. Thus, the present experiments further investigated the protective effect of GDNF as well as the protective effects of several other trophic factors. Male Fischer-344 rats were given an intracerebral injection of trophic factor (2-10 microg) 1 day before METH (5 mg/kg, s.c., 4 injections at 2-h intervals). Seven days later DA levels in the striatum were measured using high-performance liquid chromatography (HPLC). Initial experiments indicated that only intrastriatal GDNF, and not intranigral GDNF, was protective. Thereafter, all other trophic factors were administered into the striatum. Members of the GDNF family (GDNF, neurturin, and artemin) all provided significant protection against the DA-depleting effects of METH, with GDNF providing the greatest protection. Brain-derived neurotrophic factor, neurotrophin-3, acidic fibroblast growth factor, basic fibroblast growth factor, ciliary neurotrophic factor, transforming growth factor-alpha (TGF-alpha), heregulin beta1 (HRG-beta1), and amphiregulin (AR) provided no significant protection at the doses examined. These results suggest that the GDNF family of trophic factors can provide significant protection against the DA-depleting effects of neurotoxic doses of METH.

Effectiveness of Spinal Cord Stimulation in Chronic Spinal Pain: A Systematic Review.

BACKGROUND: Chronic neuropathic pain has been recognized as contributing to a significant proportion of chronic pain globally. Among these, spinal pain is of significance with failed back surgery syndrome (FBSS), generating considerable expense for the health care systems with increasing prevalence and health impact. OBJECTIVE: To assess the role and effectiveness of spinal cord stimulation (SCS) in chronic spinal pain. STUDY DESIGN: A systematic review of randomized controlled trials (RCTs) of SCS in chronic spinal pain. METHODS: The available literature on SCS was reviewed. The quality assessment criteria utilized were Cochrane review criteria to assess sources of risk of bias and Interventional Pain Management Techniques - Quality Appraisal of Reliability and Risk of Bias Assessment (IPM - QRB) criteria for randomized trials.The level of evidence was based on a best evidence synthesis with modified grading of qualitative evidence from Level I to Level V.Data sources included relevant literature published from 1966 through March 2015 that were identified through searches of PubMed and EMBASE, manual searches of the bibliographies of known primary and review articles, and all other sources. OUTCOME MEASURES: RCTs of efficacy with a minimum 12-month follow-up were considered for inclusion. For trials of adaptive stimulation, high frequency stimulation, and burst stimulation, shorter follow-up periods were considered. RESULTS: Results showed 6 RCTs with 3 efficacy trials and 3 stimulation trials. There were also 2 cost effectiveness studies available. Based on a best evidence synthesis with 3 high quality RCTs, the evidence of efficacy for SCS in lumbar FBSS is Level I to II. The evidence for high frequency stimulation based on one high quality RCT is Level II to III. Based on a lack of high quality studies demonstrating the efficacy of adaptive stimulation or burst stimulation, evidence is limited for these 2 modalities. LIMITATIONS: The limitations of this systematic review continue to require future studies illustrating effectiveness and also the superiority of high frequency stimulation and potentially burst stimulation. CONCLUSION: There is significant (Level I to II) evidence of the efficacy of spinal cord stimulation in lumbar FBSS; whereas, there is moderate (Level II to III) evidence for high frequency stimulation; there is limited evidence for adaptive stimulation and burst stimulation.

Enhanced effects of 6-hydroxydopamine on evoked overflow of striatal dopamine in aged rats.

Nigrostriatal dopamine neurons degenerate during aging, and the excessive loss of dopamine neurons that occurs with Parkinson's disease is usually confined to older individuals. Although 6-hydroxydopamine lesioning of the nigrostriatal dopamine system is a common method for producing animal models of dopamine neuron degeneration, there have been relatively few studies that have examined the effects of 6-hydroxydopamine on the dopamine systems of aged animals. The present experiments were designed to determine if nigrostriatal dopamine neurons in aged rats are more sensitive to the neurotoxic effects of 6-hydroxydopamine than those of younger rats. Young (4-month-old), middle-aged (14-month-old) and aged (24-month-old) Fischer-344 rats were given a single injection of vehicle, 50 or 100 microg 6-hydroxydopamine into the right lateral ventricle. Three to four weeks later in vivo electrochemistry was used to measure potassium-evoked overflow of dopamine in the striatum. In the young rats the 50-microg dose had no significant effect on evoked overflow of dopamine in the striatum or on post-mortem levels of dopamine in the striatum or substantia nigra. The higher dose in the young animals diminished evoked overflow of dopamine as well as tissue levels of dopamine. In the aged rats both doses of 6-hydroxydopamine led to significant decreases in evoked overflow of striatal dopamine and in tissue levels of dopamine in the striatum and substantia nigra. These results suggest that dopamine neurons of aged Fischer-344 rats are more susceptible to the toxic effects of 6-hydroxydopamine than those of younger animals.

HIV-1 protein Tat potentiation of methamphetamine-induced decreases in evoked overflow of dopamine in the striatum of the rat.

HIV-1 infection of the brain can lead to the development of clinical syndromes reminiscent of Parkinson's disease, suggesting that HIV infection may damage nigrostriatal dopamine (DA) neurons. Although the responsible mechanisms have not been well defined, neurotoxic viral proteins, such as Tat, released from infected cells may be involved. Drug abuse is a major risk factor for contracting HIV infection. Methamphetamine (METH), a psychostimulant with high abuse potential, may also be toxic to brain DA neurons. Thus, the combination of METH abuse and HIV infection may lead to substantial alterations in DA neuron functioning. The present experiments examined how Tat, alone and with METH, affects DA release in the striatum. Male rats were given an intrastriatal injection of Tat (25 micro g) or vehicle 24 h before treatment with saline or neurotoxic doses of METH. Seven days later microdialysis studies were carried out to measure potassium- and amphetamine-evoked overflow of DA from the striatum. The Tat treatment alone led to no change in potassium-evoked overflow of DA, a 20% decrease in amphetamine-evoked overflow of DA, and a 16% decrease in striatal DA content. The METH alone led to a 37-42% decrease in striatal DA overflow and content. The combined treatment with Tat and METH led to significantly greater 70-78% decreases in striatal DA overflow and content. These results indicate that Tat enhances METH-induced reductions in striatal DA release and content, possibly in a synergistic manner, and suggest that METH abusers infected with HIV may be at increased risk for basal ganglia dysfunction.

Trialing of intrathecal baclofen therapy for refractory stiff-person syndrome.

OBJECTIVE: Stiff-person syndrome (SPS) is a rare disorder of the central nervous system characterized by stiffness and muscle spasms that may be progressive in nature. When oral medication is inadequate to control muscle spasticity, intrathecal baclofen may be used. We report a patient with severe SPS and glutamate decarboxylase negative [GAD(-)] (note: GAD(-) indicates the patient has no antibodies to GAD), refractory to oral standard therapies. The patient was effectively trialed with an intrathecal catheter and subsequently treated with chronic intrathecal baclofen, which provided significant relief of spasticity symptoms. CASE REPORT: A 48-year-old white man with a history consistent with SPS presented to the clinic. His previous history showed that he met several diagnostic criteria for GAD(-) SPS and had a muscle biopsy positive for myositis. Oral medications were unable to control his muscle spasticity, preventing him from working. The patient received an intrathecal trial using a lumbar approach for placement of a thoracic catheter with an initial baclofen dose of 50 µg/d. Gradual titration to symptom relief was performed up to 150 µg/d. Functional evaluation by our physical therapist showed improved motor function, the temporary catheter was removed, and a permanent intrathecal pump placed for intrathecal baclofen infusion. The patient reported excellent symptom relief over the next 6 months and improved activity. CONCLUSIONS: Refractory SPS is difficult to treat and has few therapeutic options. We report a GAD(-) patient with SPS and resulting debilitating spasticity that was refractory to oral medications who underwent successful continuous intrathecal catheter trial of baclofen over 4 days and subsequently went on to implantation of intrathecal pump. The literature reports only 5 cases of GAD(-) SPS patients treated with intrathecal baclofen therapy, and these resulted in poor long-term success. Our patient completed a 4-day trial of intrathecal baclofen titrated to effect before pump implantation. We advocate continuous intrathecal trialing, as opposed to single-injection technique, to possibly better determine the effective therapeutic dose and ensure posttrialing successful therapy.

American Society of Interventional Pain Physicians (ASIPP) guidelines for responsible opioid prescribing in chronic non-cancer pain: Part I--evidence assessment.

BACKGROUND: Opioid abuse has continued to increase at an alarming rate since the 1990 s. As documented by different medical specialties, medical boards, advocacy groups, and the Drug Enforcement Administration, available evidence suggests a wide variance in chronic opioid therapy of 90 days or longer in chronic non-cancer pain. Part 1 describes evidence assessment. OBJECTIVES: The objectives of opioid guidelines as issued by the American Society of Interventional Pain Physicians (ASIPP) are to provide guidance for the use of opioids for the treatment of chronic non-cancer pain, to produce consistency in the application of an opioid philosophy among the many diverse groups involved, to improve the treatment of chronic non-cancer pain, and to reduce the incidence of abuse and drug diversion. The focus of these guidelines is to curtail the abuse of opioids without jeopardizing non-cancer pain management with opioids. RESULTS: 1) There is good evidence that non-medical use of opioids is extensive; one-third of chronic pain patients may not use prescribed opioids as prescribed or may abuse them, and illicit drug use is significantly higher in these patients. 2) There is good evidence that opioid prescriptions are increasing rapidly, as the majority of prescriptions are from non-pain physicians, many patients are on long-acting opioids, and many patients are provided with combinations of long-acting and short-acting opioids. 3) There is good evidence that the increased supply of opioids, use of high dose opioids, doctor shoppers, and patients with multiple comorbid factors contribute to the majority of the fatalities. 4) There is fair evidence that long-acting opioids and a combination of long-acting and short-acting opioids contribute to increasing fatalities and that even low-doses of 40 mg or 50 mg of daily morphine equivalent doses may be responsible for emergency room admissions with overdoses and deaths. 5) There is good evidence that approximately 60% of fatalities originate from opioids prescribed within the guidelines, with approximately 40% of fatalities occurring in 10% of drug abusers. 6) The short-term effectiveness of opioids is fair, whereas the long-term effectiveness of opioids is limited due to a lack of long-term (> 3 months) high quality studies, with fair evidence with no significant difference between long-acting and short-acting opioids. 7) Among the individual drugs, most opioids have fair evidence for short-term and limited evidence for long-term due to a lack of quality studies. 8) The evidence for the effectiveness and safety of chronic opioid therapy in the elderly for chronic non-cancer pain is fair for short-term and limited for long-term due to lack of high quality studies; limited in children and adolescents and patients with comorbid psychological disorders due to lack of quality studies; and the evidence is poor in pregnant women. 9) There is limited evidence for reliability and accuracy of screening tests for opioid abuse due to lack of high quality studies. 10) There is fair evidence to support the identification of patients who are non-compliant or abusing prescription drugs or illicit drugs through urine drug testing and prescription drug monitoring programs, both of which can reduce prescription drug abuse or doctor shopping. DISCLAIMER: 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."

American Society of Interventional Pain Physicians (ASIPP) guidelines for responsible opioid prescribing in chronic non-cancer pain: Part 2--guidance.

RESULTS: Part 2 of the guidelines on responsible opioid prescribing provides the following recommendations for initiating and maintaining chronic opioid therapy of 90 days or longer. 1. A) Comprehensive assessment and documentation is recommended before initiating opioid therapy, including documentation of comprehensive history, general medical condition, psychosocial history, psychiatric status, and substance use history. ( EVIDENCE: good) B) Despite limited evidence for reliability and accuracy, screening for opioid use is recommended, as it will identify opioid abusers and reduce opioid abuse. ( EVIDENCE: limited) C) Prescription monitoring programs must be implemented, as they provide data on patterns of prescription usage, reduce prescription drug abuse or doctor shopping. ( EVIDENCE: good to fair) D) Urine drug testing (UDT) must be implemented from initiation along with subsequent adherence monitoring to decrease prescription drug abuse or illicit drug use when patients are in chronic pain management therapy. ( EVIDENCE: good) 2. A) Establish appropriate physical diagnosis and psychological diagnosis if available prior to initiating opioid therapy. ( EVIDENCE: good) B) Caution must be exercised in ordering various imaging and other evaluations, interpretation and communication with the patient, to avoid increased fear, activity restriction, requests for increased opioids, and maladaptive behaviors. ( EVIDENCE: good) C) Stratify patients into one of the 3 risk categories - low, medium, or high risk. D) A pain management consultation, may assist non-pain physicians, if high-dose opioid therapy is utilized. ( EVIDENCE: fair) 3. Essential to establish medical necessity prior to initiation or maintenance of opioid therapy. ( EVIDENCE: good) 4. Establish treatment goals of opioid therapy with regard to pain relief and improvement in function. ( EVIDENCE: good) 5. A) Long-acting opioids in high doses are recommended only in specific circumstances with severe intractable pain that is not amenable to short-acting or moderate doses of long-acting opioids, as there is no significant difference between long-acting and short-acting opioids for their effectiveness or adverse effects. ( EVIDENCE: fair) B) The relative and absolute contraindications to opioid use in chronic non-cancer pain must be evaluated including respiratory instability, acute psychiatric instability, uncontrolled suicide risk, active or history of alcohol or substance abuse, confirmed allergy to opioid agents, coadministration of drugs capable of inducing life-limiting drug interaction, concomitant use of benzodiazepines, active diversion of controlled substances, and concomitant use of heavy doses of central nervous system depressants. ( EVIDENCE: fair to limited) 6. A robust agreement which is followed by all parties is essential in initiating and maintaining opioid therapy as such agreements reduce overuse, misuse, abuse, and diversion. ( EVIDENCE: fair) 7. A) Once medical necessity is established, opioid therapy may be initiated with low doses and short-acting drugs with appropriate monitoring to provide effective relief and avoid side effects. ( EVIDENCE: fair for short-term effectiveness, limited for long-term effectiveness) B) Up to 40 mg of morphine equivalent is considered as low dose, 41 to 90 mg of morphine equivalent as a moderate dose, and greater than 91 mg of morphine equivalence as high dose. ( EVIDENCE: fair) C) In reference to long-acting opioids, titration must be carried out with caution and overdose and misuse must be avoided. ( EVIDENCE: good) 8. A) Methadone is recommended for use in late stages after failure of other opioid therapy and only by clinicians with specific training in the risks and uses. ( EVIDENCE: limited) B) Monitoring recommendation for methadone prescription is that an electrocardiogram should be obtained prior to initiation, at 30 days and yearly thereafter. ( EVIDENCE: fair) 9. In order to reduce prescription drug abuse and doctor shopping, adherence monitoring by UDT and PMDPs provide evidence that is essential to the identification of those patients who are non-compliant or abusing prescription drugs or illicit drugs. ( EVIDENCE: fair) 10. Constipation must be closely monitored and a bowel regimen be initiated as soon as deemed necessary. ( EVIDENCE: good) 11. Chronic opioid therapy may be continued, with continuous adherence monitoring, in well-selected populations, in conjunction with or after failure of other modalities of treatments with improvement in physical and functional status and minimal adverse effects. ( EVIDENCE: fair). DISCLAIMER: 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."

Transient neurologic syndrome: a benign but confusing clinical problem.

Spinal anesthesia has been a safe and popular anesthetic option for patients undergoing outpatient surgical procedures of the trunk and lower extremities. Occasionally, after a spinal anesthetic, patients can develop moderate-to-severe pain in the back, hips, and legs without neurologic deficit. They will often present to the emergency department with complaints of pain and require an extensive diagnostic workup to rule out other more ominous possibilities such as spinal hematoma, infection, or nerve injury. After a negative workup and with a history of recent spinal anesthetic the patient will be diagnosed with transient neurologic syndrome. While often causing significant distress to both the patient and health care provider, transient neurologic syndrome is a benign, self-limited entity that requires only conservative therapy and usually resolves within a couple of days without intervention.