Successful Discontinuation of Systemic Opioids After Implantation of an Intrathecal Drug Delivery System

Multimodal management strategies for chronic pain after spinal surgery: a comprehensive review

"Chronic pain after spinal surgery" (CPSS) is a nonspecific term for cases in which the end result of surgery generally does not meet the preoperative expectations of the patient and surgeon. This term has replaced the previous term i.e., failed back surgery syndrome. CPSS is challenging for both patients and doctors. Despite advancements in surgical techniques and technologies, a subset of patients continue to experience persistent or recurrent pain postoperatively. This review provides an overview of the multimodal management for CPSS, ranging from conservative management to revision surgery. Drawing on recent research and clinical experience, we aimed to offer insights into the diverse strategies available to improve the quality of life of CPSS patients.

Chronic pain after spine surgery: Insights into pathogenesis, new treatment, and preventive therapy

Chronic pain after spine surgery (CPSS) is often characterized by intractable low back pain and/or radiating leg pain, and has been reported in 8-40% of patients that received lumbar spine surgery. We conducted a literature search of PubMed, MEDLINE/OVID with a focus on studies about the etiology and treatments of CPSS and low back pain. Our aim was to provide a narrative review that would help us better understand the pathogenesis and current treatment options for CPSS. This knowledge will aid in the development of optimal strategies for managing postoperative pain symptoms and potentially curing the underlying etiologies. Firstly, we reviewed recent advances in the mechanistic study of CPSS, illustrated both structural (e.g., fibrosis and scaring) and non-structural factors (e.g., inflammation, neuronal sensitization, glial activation, psychological factor) causing CPSS, and highlighted those having not been given sufficient attention as the etiology of CPSS. Secondly, we summarized clinical evidence and therapeutic perspectives of CPSS. We also presented new insights about the treatments and etiology of CPSS, in order to raise awareness of medical staff in the identification and management of this complex painful disease. Finally, we discussed potential new targets for clinical interventions of CPSS and future perspectives of mechanistic and translational research. CPSS patients often have a mixed etiology. By reviewing recent findings, the authors advocate that clinicians shall comprehensively evaluate each case to formulate a patient-specific and multi-modal pain treatment, and importantly, consider an early intraoperative intervention that may decrease the risk or even prevent the onset of CPSS.

Translational potential statement

CPSS remains difficult to treat. This review broadens our understanding of clinical therapies and underlying mechanisms of CPSS, and provides new insights which will aid in the development of novel mechanism-based therapies for not only managing the established pain symptoms but also preventing the development of CPSS.

Nanopore Generation in Biodegradable Silk/Magnetic Nanoparticle Membranes by an External Magnetic Field for Implantable Drug Delivery

Implantable devices for localized and controlled drug release are important, e.g., for therapies of cancer and chronic pain. However, most of the existing active implants are limited by the usage of nonbiodegradable materials; thus, surgery is needed to extract them after the treatment, which leads to secondary damage. Here, we show a fully biodegradable composite membrane made from silk fibroin and magnetic nanoparticles (MNPs). The membrane porosity can be remotely modified by an alternating magnetic field, which opens nanopores by local heating of MNPs in the composite allowing a liquid to diffuse through them. The stability of the silk membrane in water can be prolonged up to several months by increasing its β-sheet content through ethanol annealing. We present the following original findings. (a) Nanopores can be generated inside the silk/MNP composite membrane by exposing it to an external alternating magnetic field. (b) A longer exposure time results in more nanopore sites. (c) The controllable release of rhodamine B dye is achieved by tuning the period of exposure to the magnetic field. The obtained results demonstrate the suitability of the investigated silk/MNP composite membrane as a potential functional material for implantable drug delivery.

Efficacy of interventions to reduce long term opioid treatment for chronic non-cancer pain: systematic review and meta-analysis

OBJECTIVE

To review interventions to reduce long term opioid treatment in people with chronic non-cancer pain, considering efficacy on dose reduction and discontinuation, pain, function, quality of life, withdrawal symptoms, substance use, and adverse events.

DESIGN

Systematic review and meta-analysis of randomised controlled trials and non-randomised studies of interventions.

DATA SOURCES

Medline, Embase, PsycINFO, CINAHL, and the Cochrane Library searched from inception to July 2021. Reference lists and previous reviews were also searched and experts were contacted.

ELIGIBILITY CRITERIA FOR STUDY SELECTION

Original research in English. Case reports and cross sectional studies were excluded.

DATA EXTRACTION AND SYNTHESIS

Two authors independently selected studies, extracted data, and used the Cochrane risk-of-bias tools for randomised and non-randomised studies (RoB 2 and ROBINS-I). Authors grouped interventions into five categories (pain self-management, complementary and alternative medicine, pharmacological and biomedical devices and interventions, opioid replacement treatment, and deprescription methods), estimated pooled effects using random effects meta-analytical models, and appraised the certainty of evidence using GRADE (grading of recommendations, assessment, development, and evaluation).

RESULTS

Of 166 studies meeting inclusion criteria, 130 (78%) were considered at critical risk of bias and were excluded from the evidence synthesis. Of the 36 included studies, few had comparable treatment arms and sample sizes were generally small. Consequently, the certainty of the evidence was low or very low for more than 90% (41/44) of GRADE outcomes, including for all non-opioid patient outcomes. Despite these limitations, evidence of moderate certainty indicated that interventions to support prescribers' adherence to guidelines increased the likelihood of patients discontinuing opioid treatment (adjusted odds ratio 1.5, 95% confidence interval 1.0 to 2.1), and that these prescriber interventions as well as pain self-management programmes reduced opioid dose more than controls (intervention v control, mean difference -6.8 mg (standard error 1.6) daily oral morphine equivalent, P<0.001; pain programme v control, -14.31 mg daily oral morphine equivalent, 95% confidence interval -21.57 to -7.05).

CONCLUSIONS

Evidence on the reduction of long term opioid treatment for chronic pain continues to be constrained by poor study methodology. Of particular concern is the lack of evidence relating to possible harms. Agreed standards for designing and reporting studies on the reduction of opioid treatment are urgently needed.

REVIEW REGISTRATION

PROSPERO CRD42020140943.

Functional Profile of Systemic and Intrathecal Cebranopadol in Nonhuman Primates

BACKGROUND

Cebranopadol, a mixed nociceptin/opioid receptor full agonist, can effectively relieve pain in rodents and humans. However, it is unclear to what degree different opioid receptor subtypes contribute to its antinociception and whether cebranopadol lacks acute opioid-associated side effects in primates. The authors hypothesized that coactivation of nociceptin receptors and μ receptors produces analgesia with reduced side effects in nonhuman primates.

METHODS

The antinociceptive, reinforcing, respiratory-depressant, and pruritic effects of cebranopadol in adult rhesus monkeys (n = 22) were compared with μ receptor agonists fentanyl and morphine using assays, including acute thermal nociception, IV drug self-administration, telemetric measurement of respiratory function, and itch-scratching responses.

RESULTS

Subcutaneous cebranopadol (ED50, 2.9 [95% CI, 1.8 to 4.6] μg/kg) potently produced antinociception compared to fentanyl (15.8 [14.6 to 17.1] μg/kg). Pretreatment with antagonists selective for nociceptin and μ receptors, but not δ and κ receptor antagonists, caused rightward shifts of the antinociceptive dose-response curve of cebranopadol with dose ratios of 2 and 9, respectively. Cebranopadol produced reinforcing effects comparable to fentanyl, but with decreased reinforcing strength, i.e., cebranopadol (mean ± SD, 7 ± 3 injections) versus fentanyl (12 ± 3 injections) determined by a progressive-ratio schedule of reinforcement. Unlike fentanyl (8 ± 2 breaths/min), systemic cebranopadol at higher doses did not decrease the respiratory rate (17 ± 2 breaths/min). Intrathecal cebranopadol (1 μg) exerted full antinociception with minimal scratching responses (231 ± 137 scratches) in contrast to intrathecal morphine (30 μg; 3,009 ± 1,474 scratches).

CONCLUSIONS

In nonhuman primates, the μ receptor mainly contributed to cebranopadol-induced antinociception. Similar to nociceptin/μ receptor partial agonists, cebranopadol displayed reduced side effects, such as a lack of respiratory depression and pruritus. Although cebranopadol showed reduced reinforcing strength, its detectable reinforcing effects and strength warrant caution, which is critical for the development and clinical use of cebranopadol.

EDITOR’S PERSPECTIVE

Patient Satisfaction Following Intrathecal Targeted Drug Delivery for Benign Chronic Pain: Results of a Single-Center Survey Study

OBJECTIVES

Targeted Drug Delivery (TDD) is commonly used for the management of patients with intractable pain. Past studies have proven efficacy in pain relief and reduction in opioid use and cost-effectiveness in long-term pain management. There are few studies investigating satisfaction among patients with implanted pain pumps that are managed with targeted intrathecal medications.

MATERIAL AND METHODS

Patients in a single medical practice implanted with pain pumps for relief of intractable pain were identified and extracted from the electronic health record (EHR). Six hundred and ten active TDD patients were identified and an anonymous 18-question survey was administered to determine satisfaction with TDD therapy. During an 18-month period from May 2018 to August 2019, patients were invited to take a satisfaction survey. Both primary and secondary outcomes were reported as proportions; P < 0.05 was considered significant.

RESULTS

Four hundred and forty-three patients (74% of the active pump population) completed the survey. The majority of patients reported improvement in pain, improvement of physical function, improvement in quality of life and reduction in opioid use. Complete discontinuation of oral opioid intake was reported in 38.9% of patients. The majority of patients had a 40 cc reservoir implanted in an upper buttock pocket site and overall, 91% of patients were happy with pump pocket location.

CONCLUSION

Intrathecal TDD therapy can relieve pain and improve quality of life in patients with intractable pain and offers a reasonable alternative to long-term oral or skin patch opioid management. Patients utilizing TDD therapy reported high degrees of satisfaction.

Antinociceptive, reinforcing, and pruritic effects of the G-protein signalling-biased mu opioid receptor agonist PZM21 in non-human primates

BACKGROUND

A novel G-protein signalling-biased mu opioid peptide (MOP) receptor agonist, PZM21, was recently developed with a distinct chemical structure. It is a potent G_i/o activator with minimal β-arrestin-2 recruitment. Despite intriguing activity in rodent models, PZM21 function in non-human primates is unknown. The aim of this study was to investigate PZM21 actions after systemic or intrathecal administration in primates.

METHODS

Antinociceptive, reinforcing, and pruritic effects of PZM21 were compared with those of the clinically used MOP receptor agonists oxycodone and morphine in assays of acute thermal nociception, capsaicin-induced thermal allodynia, itch scratching responses, and drug self-administration in gonadally intact, adult rhesus macaques (10 males, six females).

RESULTS

After subcutaneous administration, PZM21 (1.0-6.0 mg kg^-1) and oxycodone (0.1-0.6 mg kg^-1) induced dose-dependent thermal antinociceptive effects (P<0.05); PZM21 was 10 times less potent than oxycodone. PZM21 exerted oxycodone-like reinforcing effects and strength as determined by two operant schedules of reinforcement in the intravenous drug self-administration assay. After intrathecal administration, PZM21 (0.03-0.3 mg) dose-dependently attenuated capsaicin-induced thermal allodynia (P<0.05). Although intrathecal PZM21 and morphine induced MOP receptor-mediated antiallodynic effects, both compounds induced robust, long-lasting itch scratching.

CONCLUSIONS

PZM21 induced antinociceptive, reinforcing, and pruritic effects similar to clinically used MOP receptor agonists in primates. Although structure-based discovery of PZM21 identified a novel avenue for studying G-protein signalling-biased ligands, biasing an agonist towards G-protein signalling pathways did not determine or alter reinforcing (i.e. abuse potential) or pruritic effects of MOP receptor agonists in a translationally relevant non-human primate model.

Association Between Oral Pain Medications and Intrathecal Opioid Dose Escalation: A Retrospective Analysis

OBJECTIVES

Patients treated with intrathecal therapy frequently require opioid dose increases to maintain analgesia. The kinetics of intrathecal opioid dose escalation are poorly understood. We hypothesized that antidepressant use, antiepileptic use, and lower baseline oral opioid intake prior to intrathecal pump implantation will be protective against intrathecal opioid dose escalation.

MATERIALS AND METHODS

Targeted drug delivery medication doses were collected from patients who had an intrathecal pump implanted between 2007 and 2016. From a sample size of 136 patients, the association between antidepressant, antiepileptic, and oral opioid use with intrathecal dose escalation was assessed using statistical models.

RESULTS

Individuals using an antiepileptic had an estimated ratio of means (97.5% CI) of opioid consumption of 0.91 (97.5% CI: [0.48, 1.73], p = 0.74) at six months, 0.83 ([0.43, 1.58], p = 0.51) at 12 months, and 0.77 ([0.40, 1.45], p = 0.36) at 24 months. Patients prescribed antidepressants had an estimated ratio of means (97.5% CI) of 1.43 ([0.77, 2.65], p = 0.19) at six months, 1.41 ([0.76, 2.63], p = 0.22) at 12 months, and 1.33 ([0.70, 2.51], p = 0.31) at 24 months. In our secondary analysis of pre-implant oral opioid use, patients treated with high oral opioid doses had a similar pattern of intrathecal dose escalation when compared to patients using low doses of oral opioids.

CONCLUSIONS

Use of antiepileptics, antidepressants, or low oral opioid doses was not associated with attenuation of intrathecal dose escalation. Intrathecal opioid dose escalation was observed to occur similarly, regardless of baseline oral analgesics concomitantly employed.

Intrathecal Drug Delivery Systems for Cancer Pain: An Analysis of a Prospective, Multicenter Product Surveillance Registry

BACKGROUND

The safety and efficacy of intrathecal drug delivery systems (IDDSs) for the treatment of cancer-related pain have been demonstrated in randomized controlled clinical trials (RCTs). Despite positive evidence for this therapy, IDDS remains underutilized to treat cancer pain. Real-world registry data augment existing safety and effectiveness data and are presented here to broaden awareness of this therapeutic option, needed for adequate cancer-related pain treatment, and as a viable tool addressing concerns with systemic opioid use.

METHODS

This prospective, long-term, multicenter (United States, Western Europe, and Latin America) registry started in 2003 to monitor the performance of SynchroMed Infusion Systems. Patient-reported outcomes were added in 2013. Before data acquisition, all sites obtained Ethics Committee/Institutional Review Board approval and written patient consent. The study was registered (NCT01524276 at clinicaltrials.gov) before patients were enrolled. Patients who provided informed consent were enrolled in the registry at initial IDDS implant or replacement.

RESULTS

Through July 2017, 1403 patients with cancer pain were enrolled and implanted. The average (minimum/maximum) age of patients was 59 years (13/93 years), with 56.6% female. The most frequent cancer types were lung, breast, colon/rectal, pancreatic, and prostate. The majority of patients whose registry follow-up ended (87%; 1141/1311) were followed through death, with 4.3% (n = 57) exiting due to device explant or therapy discontinuation; the remaining 113 (8.6%) discontinued for reasons such as transfer of care, lost to follow-up, and site closure. Pain scores within the cohort of patients providing baseline and follow-up data improved significantly at 6 (P = .0007; n = 103) and 12 (P = .0026; n = 55) months compared to baseline, with EuroQol with 5 dimensions (EuroQol-5D) scores showing significant improvement at 6 months (P = .0016; n = 41). Infection requiring surgical intervention (IDDS explant, replacement, pocket revision, irrigation and debridement, etc) was reported in 3.2% of patients.

CONCLUSIONS

Adequate and improved pain control in patients with cancer, even in advanced stages, with concurrent quality of life maintenance is attainable. Results from this large-scale, multicenter, single-group cohort supplement existing RCT data that support IDDS as a safe and effective therapeutic option with a positive benefit-risk ratio in the treatment of cancer pain.

Intrathecal Drug Delivery

Targeted intrathecal (IT) drug delivery systems (IDDS) are well established as an effective treatment of patients with chronic nonmalignant or malignant pain, and as a tool for management of patients with severe spasticity. The risk to benefit ratio of IDD makes it a relatively safe therapy for both cancer- and noncancer-related pain, but it is not free of risks, so it should be managed at specific centers. Recent technological advances, new therapeutic applications, reported complications, and the costs as well as maintenance required for this therapy require the need to stay up to date about new recommendations that may improve outcomes. This chapter reviews all technological issues regarding IDDS implantation with follow-up and pharmacological recommendations published during recent years that provide evidence-based decision-making process in the management of chronic pain and spasticity in patients.

Assessment of Health Care Utilization and Cost of Targeted Drug Delivery and Conventional Medical Management vs Conventional Medical Management Alone for Patients With Cancer-Related Pain

IMPORTANCE

Targeted drug delivery (TDD) has potential for cost savings compared with conventional medical management (CMM). Despite positive clinical and economic evidence, TDD remains underused to treat cancer pain.

OBJECTIVE

To assess the cost of TDD and CMM in treating cancer-related pain.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective economic evaluation using propensity score-matched analysis was conducted using MarketScan commercial claims data on beneficiaries receiving TDD and CMM or CMM only for cancer pain from January 1, 2009, to September 30, 2015. Participants were matched on age, sex, cancer type, comorbidity score, and pre-enrollment characteristics. Data analysis was performed from June 1 to September 30, 2017.

MAIN OUTCOMES AND MEASURES

Total 2-, 6-, and 12-month costs, number of health care encounters, length of hospital stay, additional components of cost, and health care utilization.

RESULTS

A total of 376 TDD and CMM patients (mean [SD] age, 51.88 [9.98] years; 216 [57.5%] female) and 4839 CMM only patients (mean [SD] age, 51.52 [11.16] years; 3005 [62.1%] female) were identified for study inclusion. After matching, 536 patients were included in the study: 268 patients in the TDD and CMM group and 268 in the CMM only group. Compared with CMM only, TDD and CMM was associated with mean total cost savings of $15 142 (95% CI, $3690 to $26 594; P = .01) at 2 months and $63 498 (95% CI, $4620 to $122 376; P = .03) at 12 months; cost savings at 6 months were not statistically different ($19 577; 95% CI, -$12 831 to $51 984; P = .24). The TDD and CMM group had fewer inpatient visits (2-month mean difference [MD], 1.0; 95% CI, 0.8-1.2; P < .001; 6-month MD, 1.3; 95% CI, 0.8-1.7; P < .001; 12-month MD, 2.3; 95% CI, 1.2-3.4; P < .001) and shorter hospital stays (2-month MD, 6.8 days; 95% CI, 5.0-8.7 days; P < .001; 6-month MD, 6.8 days; 95% CI, 3.1-10.5 days; P < .001; 12-month MD, 10.6 days; 95% CI, 2.9-18.3 days; P = .007). Use of CMM only was associated with greater opioid use at 12 months (MD, 3.2; 95% CI, 0.4-6.0; P = .03).

CONCLUSIONS AND RELEVANCE

Compared with CMM alone, TDD and CMM together were associated with significantly lower cost and health care utilization. The findings suggest that TDD is a cost-saving therapy that should be considered in patients with cancer for whom oral opioids are inadequate or produce intolerable adverse effects and should be expanded as health care systems transition to value-based models.

Effects of NOP-Related Ligands in Nonhuman Primates

The nociceptin/orphanin FQ peptide (NOP) receptor-related ligands have been demonstrated in preclinical studies for several therapeutic applications. This article highlights (1) how nonhuman primates (NHP) were used to facilitate the development and application of positron emission tomography tracers in humans; (2) effects of an endogenous NOP ligand, nociceptin/orphanin FQ, and its interaction with mu opioid peptide (MOP) receptor agonists; and (3) promising functional profiles of NOP-related agonists in NHP as analgesics and treatment for substance use disorders. NHP models offer the most phylogenetically appropriate evaluation of opioid and non-opioid receptor functions and drug effects. Based on preclinical and clinical data of ligands with mixed NOP/MOP receptor agonist activity, several factors including their intrinsic efficacies for activating NOP versus MOP receptors and different study endpoints in NHP could contribute to different pharmacological profiles. Ample evidence from NHP studies indicates that bifunctional NOP/MOP receptor agonists have opened an exciting avenue for developing safe, effective medications with fewer side effects for treating pain and drug addiction. In particular, bifunctional NOP/MOP partial agonists hold a great potential as (1) effective spinal analgesics without itch side effects; (2) safe, nonaddictive analgesics without opioid side effects such as respiratory depression; and (3) effective medications for substance use disorders.

Does Opioid Tapering in Chronic Pain Patients Result in Improved Pain or Same Pain vs Increased Pain at Taper Completion? A Structured Evidence-Based Systematic Review

Objective

To support or refute the hypothesis that opioid tapering in chronic pain patients (CPPs) improves pain or maintains the same pain level by taper completion but does not increase pain.

Methods

Of 364 references, 20 fulfilled inclusion/exclusion criteria. These studies were type 3 and 4 (not controlled) but reported pre/post-taper pain levels. Characteristics of the studies were abstracted into tabular form for numerical analysis. Studies were rated independently by two reviewers for quality. The percentage of studies supporting the above hypothesis was determined.

Results

No studies had a rejection quality score. Combining all studies, 2,109 CPPs were tapered. Eighty percent of the studies reported that by taper completion pain had improved. Of these, 81.25% demonstrated this statistically. In 15% of the studies, pain was the same by taper completion. One study reported that by taper completion, 97% of the CPPs had improved or the same pain, but CPPs had worse pain in 3%. As such, 100% of the studies supported the hypothesis. Applying the Agency for Health Care Policy and Research Levels of Evidence Guidelines to this result produced an A consistency rating.

Conclusions

There is consistent type 3 and 4 study evidence that opioid tapering in CPPs reduces pain or maintains the same level of pain. However, these studies represented lower levels of evidence and were not designed to test the hypothesis, with the evidence being marginal in quality with large amounts of missing data. These results then primarily reveal the need for controlled studies (type 2) to address this hypothesis.

Efficacy of a Targeted Drug Delivery on-Demand Bolus Option for Chronic Pain

BACKGROUND AND OBJECTIVES

Intrathecal targeted drug delivery systems historically required physician office visits for dose adjustment to manage fluctuating pain. A wireless device now enables patients to supplement their basal intrathecal infusion with a programmed on-demand bolus dose. We sought to quantify the change in oral breakthrough opioid need associated with the use of an intrathecal bolus in comparison to those treated with the basal infusion alone.

METHODS

Demographic, dosage, bolus usage and longevity data were extracted from the historical medical record of 69 patients (18/51 bolus/nonbolus) followed continuously at our center. Medication consumption and Pain Disability Index measures were obtained at baseline and most recent follow-up.

RESULTS

Among patients with the bolus option, only 2 (11%; confidence interval [CI] 0% to 26%) continued to require oral opiates to manage breakthrough pain compared to 29 (57%; CI 43% to 71%) without the bolus option. The Pain Disability Index score decreased by 19% in patients with the bolus option and by 25% in those with the basal infusion. Total daily intrathecal opioid intake was 34% lower in the group with the bolus device.

CONCLUSIONS

Utilizing an intrathecal bolus to treat incident pain was a safe way to manage unpredictable breakthrough pain and may represent a cost-saving opportunity by eliminating the need for oral analgesic medications.

Treatment Options for Failed Back Surgery Syndrome Patients With Refractory Chronic Pain: An Evidence Based Approach

STUDY DESIGN

A significant number of lumbar postsurgical patients continue to suffer persistent pain and limited function and are termed to have "Failed back surgery syndrome" (FBSS). This review evaluates clinical trial data for the treatment of FBSS patients.

OBJECTIVE

Using an evidence-based approach to evaluate FBSS treatments will assist clinicians in choosing the most effective options for FBSS patients. Furthermore, reducing the utilization of less effective therapies may result in substantial financial savings for this patient population.

SUMMARY OF BACKGROUND DATA

Treatments for FBSS may be generally categorized as physical therapy and exercise, medications, interventional procedures, neuromodulation, and reoperation. Careful review and classification of the level of evidence available for each category of treatment for FBSS patients will help guide clinical decision-making.

METHODS

A literature review was performed for FBSS treatments. The publications were arranged hierarchically according to the North American Spine Society's guidelines as randomized controlled trials (RCTs), prospective studies, retrospective chart, and systematic reviews. Book chapters, nonsystematic reviews, and expert opinions were excluded. The review focused on studies with at least 20 FBSS patients and 6-month follow-up.

RESULTS

Evidence is weak for medications and reoperation, but strong for active exercise and interventional procedures such as adhesiolysis. The strongest evidence for long-term treatment is for spinal cord stimulation (SCS), showing favorable Level I RCT results compared with conventional medical management and reoperation. In addition, high-frequency SCS at 10 kHz has demonstrated superiority over traditional, low-frequency SCS for treating low back and leg pain in a recent Level I RCT.

CONCLUSION

Clinicians may increasingly utilize levels of evidence during their evaluation of each FBSS patient to render the best therapeutic plan, likely resulting in improved long-term pain control and reducing costs by avoiding less effective modalities. New directions in SCS show promising results for the treatment of FBSS.

LEVEL OF EVIDENCE

1.

The Polyanalgesic Consensus Conference (PACC): Recommendations for Trialing of Intrathecal Drug Delivery Infusion Therapy

INTRODUCTION

Intrathecal (IT) drug infusion is an appropriate and necessary tool in the algorithm to treat refractory cancer and noncancer pain. The decision-making steps/methodology for selecting appropriate patients for implanted targeted drug delivery systems is controversial and complicated. Therefore, a consensus on best practices for determining appropriate use of IT drug infusion may involve testing/trialing this therapy before implantation.

METHODS

This current Polyanalgesic Consensus Conference (PACC) update was designed to address the deficiencies and emerging innovations since the previous PACC convened in 2012. A literature search identified publications available since the previous PACC publications in 2014, and relevant sources were contributed by the PACC members. After reviewing the literature, the panel determined the evidence levels and degrees of recommendations. The developed consensus was ranked as strong (>80%), moderate (50-79%), or weak (<49%).

RESULTS

The trialing for IT drug delivery systems (IDDS) remains an area of continued controversy. The PACC recommendations for trialing are presented in 34 consensus points and cover trialing for morphine, ziconotide, and medication admixtures; starting doses and titration practices; measurements of success; trial settings and monitoring; management of systemic opioids during trialing; and the role of psychological evaluation. Finally, the PACC describes clinical scenarios in which IT trialing is required or not required.

CONCLUSION

The PACC provides consensus guidance on best practices of trialing for IDDS implants. In addition, the PACC recommends that no trial may be required in certain patient populations.

Intrathecal Analgesic Drug Delivery is Effective for Analgesia in a Patient with Post-Poliomyelitis Syndrome: A Case Report

Patient: Female, 45

Final Diagnosis: Post-poliomyelitis syndrome

Symptoms: Chronic pain

Medication: Fentanyl • Oxycodone • Gabapentin • Naproxen • Paracetamol

Clinical Procedure: Intrathecal analgesic drug delivery

Specialty: Anesthesiology