Device-Related Complications Associated with Cylindrical Lead Spinal Cord Stimulator Implants: A Comprehensive Review.

PURPOSE OF REVIEW: Spinal cord stimulation (SCS) is an increasingly utilized therapy for the treatment of neuropathic pain conditions. Though minimally invasive and reversable, there are several important device-related complications that physicians should be aware of before offering this therapy to patients. The aim of this review is to synthesize recent studies in device-related SCS complications pertaining to cylindrical lead implantation and to discuss etiologies, symptoms and presentations, diagnostic evaluation, clinical implications, and treatment options. RECENT FINDINGS: Device-related complications are more common than biologic complications. Device-related complications covered in this review include lead migration, lead fracture, lead disconnection, generator failure, loss of charge, generator flipping, hardware related pain, and paresthesia intolerance. The use of SCS continues to be an effective option for neuropathic pain conditions. Consideration of complications prior to moving forward with SCS trials and implantation is a vital part of patient management and device selection. Knowledge of these complications can provide physicians and other healthcare professionals the ability to maximize patient outcomes.

Pain Scales: What Are They and What Do They Mean.

PURPOSE OF REVIEW: It is essential to have validated and reliable pain measurement tools that cover a wide range of areas and are tailored to individual patients to ensure effective pain management. The main objective of this review is to provide comprehensive information on commonly used pain scales and questionnaires, including their usefulness, intended purpose, applicability to different patient populations, and associated advantages and disadvantages. RECENT FINDINGS: Acute pain questionnaires typically focus on measuring the severity of pain and the extent of relief achieved through interventions. Chronic pain questionnaires evaluate additional aspects such as pain-related functional limitations, psychological distress, and psychological well-being. The selection of an appropriate pain scale depends on the specific assessment objectives. Additionally, each pain scale has its strengths and limitations. Understanding the differences among these pain scales is essential for selecting the most appropriate tool tailored to individual patient needs in different settings. CONCLUSION: Medical professionals encounter challenges in accurately assessing pain. Physicians must be familiar with the different pain scales and their applicability to specific patient population.

Discrepancy Between Reported and Calculated Pain Reduction in Patients With Spinal Cord Stimulation Therapy and Lack of Agreement Between Patient Satisfaction and Degree of Pain Relief.

OBJECTIVES: This study aimed to determine agreement between reported percentage pain reduction (RPPR) and calculated percentage pain reduction (CPPR) in patients with percutaneous spinal cord stimulation (SCS) implants, and to correlate RPPR and CPPR with patient satisfaction. We also sought to determine which patient-reported outcome measures are most improved in patients with SCS. MATERIALS AND METHODS: Fifty patients with percutaneous spinal cord stimulator implants with a mean follow-up of 51.1 months were interviewed and surveyed to assess their pain level, impression of degree of pain relief, satisfaction with the therapy, and desire to have the device again. Baseline pain level was obtained from their preimplant records. RESULTS: Overall, RPPR was found to be 53.3%, whereas CPPR was 44.4%. Of all patients, 21 reported <50% pain reduction; however, most of these (12/21, 57%) were satisfied with the outcome of therapy. In terms of individual improvement in outcomes, activities of daily life was the most improved measure at 82%, followed by mood, sleep, medication use, and health care utilization at 74%, 62%, 50%, and 48%, respectively. CONCLUSIONS: RPPR appears to be a complex outcome measure that may not agree with CPPR. Overall RPPR is greater than the CPPR. On the basis of our data, these independently valid measures should not be used interchangeably. A 50% pain reduction threshold is not a requisite for patient satisfaction and desire to have the device again. Activities of daily living was the most improved measure in this cohort, followed by mood, sleep, medication usage, and decrease in health care utilization.

The Neurostimulation Appropriateness Consensus Committee (NACC)®: Recommendations for Spinal Cord Stimulation Long-Term Outcome Optimization and Salvage Therapy.

INTRODUCTION: The International Neuromodulation Society (INS) has recognized a need to establish best practices for optimizing implantable devices and salvage when ideal outcomes are not realized. This group has established the Neurostimulation Appropriateness Consensus Committee (NACC)® to offer guidance on matters needed for both our members and the broader community of those affected by neuromodulation devices. MATERIALS AND METHODS: The executive committee of the INS nominated faculty for this NACC® publication on the basis of expertise, publications, and career work on the issue. In addition, the faculty was chosen in consideration of diversity and inclusion of different career paths and demographic categories. Once chosen, the faculty was asked to grade current evidence and along with expert opinion create consensus recommendations to address the lapses in information on this topic. RESULTS: The NACC® group established informative and authoritative recommendations on the salvage and optimization of care for those with indwelling devices. The recommendations are based on evidence and expert opinion and will be expected to evolve as new data are generated for each topic. CONCLUSIONS: NACC® guidance should be considered for any patient with less-than-optimal outcomes with a stimulation device implanted for treating chronic pain. Consideration should be given to these consensus points to salvage a potentially failed device before explant.

Incidence of subsequent surgical decompression following minimally invasive approaches to treat lumbar spinal stenosis: A retrospective review.

BACKGROUND CONTEXT: Surgical decompression is the definitive treatment for managing symptomatic lumbar spinal stenosis; however, select patients are poor surgical candidates. Consequently, minimally invasive procedures have gained popularity, but there exists the potential for failure of therapy necessitating eventual surgical decompression. PURPOSE: To evaluate the incidence and characteristics of patients who require surgical decompression following minimally invasive procedures to treat lumbar spinal stenosis. STUDY DESIGN/SETTING: Retrospective review. PATIENT SAMPLE: Patients who underwent minimally invasive procedures for lumbar spinal stenosis (Percutaneous Image-guided Lumbar Decompression [PILD] or interspinous spacer device [ISD]) and progressed to subsequent surgical decompression within 5 years. OUTCOME MEASURES: The primary outcome was the rate of surgical decompression within 5 years following the minimally invasive approach. Secondary outcomes included demographic and comorbid factors associated with increased odds of requiring subsequent surgery. METHODS: Patient data were collected using the PearlDiver-Mariner database. The rate of subsequent decompression was described as a percentage while univariable and multivariable regression analysis was used for the analysis of predictors. RESULTS: A total of 5278 patients were included, of which 3222 (61.04%) underwent PILD, 1959 (37.12%) underwent ISD placement, and 97 (1.84%) had claims for both procedures. Overall, the incidence of subsequent surgical decompression within 5 years was 6.56% (346 of 5278 patients). Variables associated with a significantly greater odds ratio (OR) [95% confidence interval (CI)] of requiring subsequent surgical decompression included male gender and a prior history of surgical decompression by 1.42 ([1.14, 1.77], p = 0.002) and 2.10 times ([1.39, 3.17], p < 0.001), respectively. In contrast, age 65 years and above, a diagnosis of obesity, and a Charlson Comorbidity Index score of three or greater were associated with a significantly reduced OR [95% CI] by 0.64 ([0.50, 0.81], p < 0.001), 0.62 ([0.48, 0.81], p < 0.001), and 0.71 times ([0.56, 0.91], p = 0.007), respectively. CONCLUSIONS: Minimally invasive procedures may provide an additional option to treat symptomatic lumbar spinal stenosis in patients who are poor surgical candidates or who do not desire open decompression; however, there still exists a subset of patients who will require subsequent surgical decompression. Factors such as gender and prior surgical decompression increase the likelihood of subsequent surgery, while older age, obesity, and a higher Charlson Comorbidity Index score reduce it. These findings aid in selecting suitable surgical candidates for better outcomes in the elderly population with lumbar spinal stenosis.

The contralateral oblique fluoroscopic view is associated with a lower incidence of postdural puncture headache in patients undergoing percutaneous spinal cord stimulation.

BACKGROUND: Spinal cord stimulation (SCS) is a minimally invasive therapy that is increasingly used to treat refractory neuropathic pain. Although this technique has a low incidence of serious long-term adverse sequelae, the risk of complications such as inadvertent dural puncture remains. OBJECTIVES: The goal of this article was to determine the impact of the contralateral oblique (CLO) fluoroscopic view incidence of postdural puncture headache (PDPH) during spinal cord stimulator implantation as compared to lateral fluoroscopic view. METHODS: This was a single academic institution retrospective analysis of electronic medical records spanning an approximate 20-year time period. Operative and postoperative notes were reviewed for details on dural puncture, including technique and spinal level of access, the development of a PDPH, and subsequent management. RESULTS: Over nearly two decades, a total of 1637 leads inserted resulted in 5 PDPH that were refractory to conservative measures but responded to epidural blood patch without long-term complications. The incidence of PDPH per lead insertion utilizing loss of resistance and lateral fluoroscopic guidance was 0.8% (4/489). However, adoption of CLO guidance was associated with a lower rate of PDPH at 0.08% (1/1148), p < 0.02. CONCLUSIONS: The incorporation of the CLO view to guide epidural needle placement can decrease the odds of a PDPH during percutaneous SCS procedures. This study further provides real-world data supporting the potential enhanced accuracy of epidural needle placement in order to avoid unintentional puncture or trauma to deeper spinal anatomic structures.

Incidence and Predictors of Inadvertent Dural Puncture After Percutaneous Spinal Cord Stimulation: A Retrospective Database Analysis.

OBJECTIVES: Inadvertent dural puncture (IDP) is a known complication associated with traditional neuraxial procedures; however, its characterization after percutaneous spinal cord stimulation (SCS) lead placement has yet to be clearly established in large population studies. This retrospective analysis aims to understand the incidence and associated characteristics of patients with IDP after percutaneous SCS lead placement. MATERIALS AND METHODS: The PearlDiver Mariner database of national all-payer claims was used to identify patients who received percutaneous SCS leads and had a claim for IDP (intraoperative IDP or postdural puncture headache [PDPH] claim) within 45 days. The primary outcome was to determine the overall incidence of IDP. Secondary outcomes included an evaluation of associated risk factors for IDP and treatments used in symptomatic management. RESULTS: A total of 90,952 patients who underwent percutaneous lead SCS placement were included. The incidence of IDP was 0.48% (436/90,952 patients). Older age (odds ratio [OR]: 0.96; 95% CI: 0.95-0.97; p < 0.0001) and male sex (OR: 0.66; 95% CI: 0.53-0.81; p < 0.001) had a lower odds of having a claim for IDP, whereas a history of IDP was associated with a higher OR (95% CI) by 13.72 times (10.72-17.58) (p < 0.0001). Of the IDP patients, 64% (277/436 patients) had a claim for a therapeutic blood patch. Discrepancy in type of claim for IDP was observed, with most being for PDPH. CONCLUSIONS: Our findings suggest that IDP after percutaneous SCS lead placement is an uncommon event; however, certain factors are associated with its development. Overall, early recognition of IDP after percutaneous SCS lead placement is imperative to facilitate the delivery of targeted treatments and prevent further harmful consequences to the patient.

Socioeconomic Disparities in the Utilization of Spinal Cord Stimulation Therapy in Patients with Chronic Pain.

OBJECTIVES: Spinal cord stimulation (SCS) therapies are used in the management of patients with complex regional pain syndrome I (CRPS I) and failed back surgery syndrome (FBSS). The purpose of this study was to investigate the racial and health insurance inequalities with SCS therapy in patients with chronic pain who had CRPS I and FBSS. METHODS: Patients with chronic pain who had a discharge diagnosis of FBSS and CRPS I were identified using the National Inpatient Sample database. Our primary outcome was defined as the history of SCS utilization by race/ethnicity, income quartile, and insurance status. Multivariable logistic regression was used to determine the variables associated with utilization of SCS therapy. RESULTS: Between 2011 and 2015, 40,858 patients who were hospitalized with a primary diagnosis of FBSS and/or CRPS I were identified. Of these patients, 1,082 (2.7%) had a history of SCS therapy. Multivariable regression analysis revealed that compared to White patients, Black and Hispanic patients had higher odds of having SCS therapy (Black patients: odds ratio [OR] = 1.41; 95% confidence interval [CI], 1.12 to 1.77; P = 0.003; Hispanic patients: OR = 1.41; 95% CI, 1.10 to 1.81; P = 0.007). Patients with private insurance had significantly higher odds of having SCS therapy compared with those with Medicare (OR = 1.24; 95% CI, 1.08 to 1.43; P = 0.003). Compared to patients with Medicare, Medicaid patients had lower odds of having SCS therapy (OR = 0.50; 95% CI, 0.36 to 0.70; P < 0.001). CONCLUSIONS: Our study suggests that socioeconomic disparities may exist in the utilization of SCS among hospitalized patients with CRPS I and FBSS the United States. However, confirming these data from other administrative databases, in the outpatient setting, may shed more insight.

Lumbar Epidural Contrast Spread Patterns for the Interlaminar Approach: Three-Dimensional Analysis Using Antero-Posterior, Lateral, and Contralateral Oblique Views.

OBJECTIVE: To describe and analyze lumbar epidural contrast spread patterns in antero-posterior (AP), lateral, and contralateral oblique (CLO) views. METHODS: Lumbar epidural contrast spread patterns after interlaminar injection were prospectively collected in AP, lateral, and several CLO views and analyzed for multiple variables; three-dimensional mapping was also performed. RESULTS: Epidural contrast patterns were prospectively analyzed in 28 subjects. The median volume of contrast injected was 2 mL; the AP view was more sensitive than the lateral view to detect foraminal uptake (13/28, 46%, 95% confidence interval [CI] = 27-66%, vs 7/28, 25%, 95% CI = 11-45% subjects). CLO view demonstrated the most consistent location for epidural contrast spread, with contrast contacting the ventral laminar margin in 28/28 (100%, 95% CI = 87-100%) patients. The most common location of contrast spread in the lateral view was at the facet joint lucency, with only 8/28 (29%, 95% CI = 13%-49%) subjects showing contrast contacting the spinolaminar junction. Lateral view was more sensitive than the CLO view in ventral epidural contrast spread detection. The extent and distribution of the spread did not bear any relationship to the volume injected or to the needle location in AP view. CONCLUSIONS: CLO view provides the most consistent landmark for lumbar epidural contrast spread, and lateral view is most suited to confirming ventral epidural spread. The AP view may be the most optimal for determining target access when considering access to the dorsal root ganglia; in an individual patient, the volume injected and needle location in AP view do not reliably predict target access. The volume to be injected and the need to re-access or obtain multisite access must be prospectively determined, based upon observation of the spread.

Post Dural Puncture Headache, Managed with Epidural Blood Patch, Is Associated with Subsequent Chronic Low Back Pain in Patients: a Pilot Study.

PURPOSE OF REVIEW: Post dural puncture headache (PDPH) is a relatively common complication which may occur in the setting of inadvertent dural puncture (DP) during labor epidural analgesia and during intentional DP during spinal anesthetic placement or diagnostic lumbar puncture. Few publications have established the long-term safety of an epidural blood patch (EBP) for the treatment of a PDPH. RECENT FINDINGS: The aim of this pilot study was to examine the association of chronic low back pain (LBP) in patients who experienced a PDPH following labor analgesia and were treated with an EBP. A total of 146 patients were contacted and completed a survey questionnaire via telephone. The EBP group was found to be more likely to have chronic LBP (percentage difference 20% [95% CI 6-33%], RR 2.6 [95% CI 1.3-5.2]) and also LBP < 6 (percentage difference 24% [95% CI 9- 37%], RR 2.3 [95% CI 1.3-4.1]). There were no significant differences in the severity and descriptive qualities of pain between the EBP and non-EBP groups. Our findings suggest that PDPH treated with an EBP is associated with an increased prevalence of subsequent low back pain in parturients. The findings of this pilot study should spur further prospective research into identifying potential associations between DP, EBP, and chronic low back pain.

Sacral Insufficiency Fractures: a Review of Risk Factors, Clinical Presentation, and Management.

PURPOSE OF THE REVIEW: Sacral insufficiency fractures (SIF) are a common and often underdiagnosed source of low back pain. In patients with SIF, there is both a compromised sacroiliac joint and weakened sacrum, resulting in decreased resistance to torsional stress, leading to fracture. While conservative medical management is a safe option, minimally invasive intervention may provide improved short and long-term relief of low back pain in patients presenting with SIF. This comprehensive review is undertaken to provide an update to the current understanding of SIF with description of risk factors, clinical presentation, and management. RECENT FINDINGS: Sacroplasty is a minimally invasive procedure in which polymethylmethacrylate (PMMA) cement is inserted into bone to improve its structural integrity and alleviate symptoms. Balloon sacroplasty (BSP) has also been successful in alleviating pain with minimal cement leakage in SIF patients. Various other interventional techniques, including navigation-assisted screw fixation have been used to address SIF and have shown improvement in pain with minimal side effects. This review included various modalities of treatments available to manage SIF. This review shows that in comparison with nonsurgical management, sacroplasty has been shown to have greater pain reduction and improved mobility.

Considerations and Implications of Cannabidiol Use During Pregnancy.

PURPOSE OF REVIEW: Cannabis is a naturally occurring plant that is composed of over sixty phytocannabinoids, of which cannabidiol (CBD) has been recently identified as having therapeutic potential. RECENT FINDINGS: Although not clearly understood in its mechanism of action, CBD contains potent anti-inflammatory, anti-hyperalgesia, and analgesic qualities now being further analyzed for its use in the treatment of a plethora of diseases. Related to its large safety profile and lack of psychoactive effects typically associated with cannabis and tetrahydrocannabinol (THC), CBD is being used more frequently for self-treatment of chronic pain, anxiety, and depression. With the help of broad marketing, CBD is being used by numerous people, including pregnant women who use CBD as an anti-emetic. Since marijuana is legalized in many states in the USA, the use of CBD has increased not only in the general population but also in specific groups such as pregnant women with chronic pain. Despite CBD's accessibility, there are limited studies showing its safety during pregnancy. While the use of cannabis has been well explored in terms of the effects on pregnancy, the use of CBD during pregnancy thus far has limited literature. The goal of this investigation is to impart the current understanding of CBD and its effects of pregnancy.

Gut Microbiome Dysbiosis and Depression: a Comprehensive Review.

PURPOSE OF REVIEW: The human gut microbiome is involved in a bi-directional communication pathway with the central nervous system (CNS), termed the microbiota-gut-brain axis. The microbiota-gut-brain axis is believed to mediate or modulate various central processes through the vagus nerve. The microbiota-gut-brain axis is involved with the production of microbial metabolites and immune mediators which trigger changes in neurotransmission, neuroinflammation, and behavior. Little is understood about the utilization of microbiome manipulation to treat disease. RECENT FINDINGS: Though studies exploring the role of the microbiome in various disease processes have shown promise, mechanisms remain unclear and evidence-based treatments for most illnesses have not yet been developed. The animal studies reviewed in the present investigation include an array of basic science studies that clarify mechanisms by which the microbiome may affect mental health. More evidence is needed, particularly as it relates to translating this work to humans. The studies presented in this review demonstrate encouraging results in the treatment of depression. Limitations include small sample sizes and heterogeneous methodology. The exact mechanism by which the gut microbiota causes or alters neuropsychiatric disease states is not fully understood. In this review, we focus on recent studies investigating the relationship between gut microbiome dysbiosis and the pathogenesis of depression.

The Evolving Role of High-Frequency Spinal Cord Stimulation as Salvage Therapy in Neurostimulation.

BACKGROUND: High-frequency 10-kHz spinal cord stimulation (10-kHz SCS) has shown promise in multicenter prospective trials for the management of chronic back and leg pain. Traditional spinal cord stimulation (t-SCS) has a long history of effectiveness in chronic neuropathic syndromes but not uncommonly can fail to provide long-term relief, leaving a significant group of patients with unsatisfactory outcomes. There is mounting evidence that 10-kHz SCS may offer relief in this subset of patients. METHODS: The purpose of this retrospective analysis was to report a single-institution long-term experience of 10-kHz SCS in patients who did not get adequate pain relief with prior t-SCS devices. A temporary trial of 10-kHz SCS was carried out for 7 days, and those experiencing an average of 50% reduction in pain intensity underwent implantation. Patients were classified as moderate responders if relief was 31% to 50% and excellent responders if pain relief exceeded 50%. RESULTS: Thirty-one patients who had experienced failed t-SCS primarily from poor paresthesia coverage underwent a trial of 10-kHz SCS and 29 underwent implantation. Twenty-eight patients were available for analysis, with 57.1% experiencing 30% response and 46.4% experiencing excellent response at a median follow-up of 21.2 (±8.4) months. CONCLUSIONS: This small single-institution study suggests that a significant proportion of patients with previously failed t-SCS may achieve clinically meaningful and durable pain relief with 10-kHz SCS.

Explantation of Percutaneous Spinal Cord Stimulator Devices: A Retrospective Descriptive Analysis of a Single-Center 15-Year Experience.

OBJECTIVES: The aims of this study were to identify the reasons for explanation of spinal cord stimulator (SCS) devices and to further quantify the proportions and time lines of these causes of explantation in order to determine improvement opportunities for the development of best practices. DESIGN: Retrospective, single academic center. MATERIALS AND METHODS: Patients who were implanted with percutaneous SCS devices from 2002 to 2015 and with follow-up available until the end of September 2017 were included in this retrospective chart analysis. RESULTS: Of the 356 patients trialed, 252 underwent implantation of an SCS device with a permanent to trial ratio of 71%. Of the patients who had a permanent implant, 50% had failed back surgery syndrome, 25% had complex regional pain syndrome, and 25% had other diagnoses. At the end of the study period, the explantation rate was 30%. The causes for explantation included biological complications (26.6%), paresthesia limitations or side effects (26.6%), hardware complications (13.3%), ineffective pain control (28%), and no further need for stimulation therapy (5.3%). CONCLUSIONS: Device removal is not uncommon, and opportunities to enhance the long-term success of SCS devices do exist. These include modification of trialing methods, achieving better paresthesia overlay, using magnetic resonance imaging (MRI) conditional equipment, development of robust technologies and hardware to reduce equipment malfunction, and improving efficacy with new innovative wave forms.

Government Legislation in Response to the Opioid Epidemic.

PURPOSE OF REVIEW: Opioid misuse and abuse in the USA has evolved into an epidemic of tragic pain and suffering, resulting in the estimated death of over 64,000 people in 2016. Governmental regulation has escalated alongside growing awareness of the epidemic's severity, both on the state and federal levels. RECENT FINDINGS: This article reviews the timeline of government interventions from the late 1990s to today, including the declaration of the opioid crisis as a national public health emergency and the resultant changes in funding and policy across myriad agencies. Aspects of the cultural climate that fuel the epidemic, and foundational change that may promote sustained success against it, are detailed within as well. As a consequence of misuse and abuse of opioids, governmental regulation has attempted to safeguard society, and clinicians should appreciate changes and expectations of prescribers.

High-Frequency Spinal Cord Stimulation at 10 kHz for the Treatment of Complex Regional Pain Syndrome: A Case Series of Patients With or Without Previous Spinal Cord Stimulator Implantation.

BACKGROUND: High-frequency spinal cord stimulation at 10 kHz (HF10-SCS) has been demonstrated to provide enhanced and durable pain relief in patients with chronic back and radiating leg pain. Patients with pain related to complex regional pain syndrome (CRPS) in the chronic stages are commonly challenging to treat and often receive traditional spinal cord stimulation (SCS). Very little information is currently available about the therapeutic outcomes following application of high-frequency stimulation in this cohort of patients. METHODS: The purpose of the retrospective case series was to report on the initial experience of HF10-SCS in 13 patients with CRPS, some of whom had been exposed to low-frequency SCS. A temporary trial of HF10-SCS was carried out for 1 week, and those achieving a minimum of 50% pain intensity reduction underwent implantation. Successful responders were those who achieved a 50% decrease in pain intensity on subsequent follow-up. RESULTS: Thirteen patients were trialed, 12 of whom went on to receive a permanent implant. Of the patients receiving permanent implants, the responder rate (50% pain relief) was 67% (95% confidence interval [CI] 0.34 to 0.90), with an average follow-up period of 12.1 ± 4.6 months. Of the 5 patients who had sympathetically independent pain, 3 were responders, and of the 7 patients who had sympathetically mediated pain, 5 were responders. There were no adverse events. CONCLUSION: This small case series suggests that HF10-SCS may be a viable option for patients with CRPS who have chronic intractable pain, including those who had suboptimal results from traditional SCS.

Discontinuation of Chronic Opiate Therapy After Successful Spinal Cord Stimulation Is Highly Dependent Upon the Daily Opioid Dose.

OBJECTIVES: The aim of this study was to determine if any of the factors recorded on a standard clinical history of a patient considered for spinal cord stimulation (SCS) would be associated with reduction or cessation of opioids following implantation. DESIGN: Retrospective, single academic center. METHODS: Patients included in the chart analysis underwent implantation of percutaneous SCS devices from 1999 to 2015 with follow-up until the end of September 2018. Patients who achieved at least an average of 50% pain reduction were included for analysis of daily opioid intake. Patients were then divided into 4 groups that included no opioid use, stable opioid daily dose, weaned opioid dose, and complete cessation of opioids. Statistical methods were used to analyze for associations between opioid intake after SCS insertion and usual elements of a clinical history, including adjuvant medications, numeric pain rating, past medical history, psychiatric illness, substance abuse, employment, and smoking history. RESULTS: In a group of 261 patients who had undergone implantation, 214 met the criteria for analysis and had a median age of 50 years, with majority having the diagnoses of failed back surgery syndrome and complex regional pain syndrome. The only factor that was associated with complete cessation of opioid use was a median dose of 30 mg of morphine per day (P < 0.01) and was observed in 15% of subjects who used opioids preoperatively. CONCLUSION: The elimination of opioid dependence following initiation of SCS therapy is highly dependent on the daily dose.

Trends of Opioid Use Disorder Among Hospitalized Patients With Chronic Pain.

BACKGROUND: Patients with chronic pain treated with opioids are at an increased risk for opioid misuse or opioid use disorder (OUD). Recent years have seen a stark increase in abuse, misuse, and diversion of prescription opioid medications. The aim of this study was to investigate trends in changing rates of opioid use disorder among patients with chronic pain. METHODS: The National Inpatient Sample (NIS) database identified chronic pain admissions with OUD from 2011 to 2015. Patients were identified from the NIS database using International Classification of Diseases (9th and 10th revisions) diagnosis codes for chronic pain and OUD. Annual estimates and trends were determined for OUD, patient characteristics, OUD among subgroups of chronic pain conditions, and discharge diagnosis. RESULTS: We identified 10.3 million patients with chronic pain. Of these, 680,631 patients were diagnosed with OUD. The number of patients with OUD increased from 109,222 in 2011 to 172,680 in 2015 (P < 0.001). Similarly, there were upward trends of OUD among females (53.2% to 54.5%; P = 0.09), patients 65 to 84 years of age (11.8% to 17%; P < 0.001), Medicare-insured patients (39.5% to 46.0%; P < 0.01), patients with low annual household incomes (27.8% to 33.3%; P < 0.001), and patients with cannabinoid use disorder (7.2% to 8.3%; P = 0.01). The prevalence of OUD increased from 2011 to 2015 in patients with chronic regional pain syndrome (5.53% to 7.46%; P = 0.01) and spondylosis (1.32% to 1.81%; P < 0.001). CONCLUSIONS: These findings suggest that the prevalence of OUD increased substantially from 2011 to 2015. Disparities of OUD with increasing opioid use among vulnerable populations including women, those with Medicare insurance, tobacco use disorder, and low annual income should be explored further.

Prospective Assessment of Pain and Comfort in Chronic Pain Patients Undergoing Interventional Pain Management Procedures.

Objective: Interventional pain management procedures have an important role in the management of chronic pain. The present study seeks to identify the proportion of patients who experience severe pain during pain procedures either with or without sedation. There is then an attempt to identify any association of high pain levels with factors such as age, gender, ethnicity, preprocedure pain level, procedure type, tobacco use, and baseline pharmaceuticals taken for both pain and/or mood disorder management. Methods: This is a prospective survey study evaluating patients' discomfort during interventional pain procedures in an outpatient academic facility. Patient discomfort was assessed by the PROcedural Sedation Assessment Survey (PROSAS) and modified for nonsedation cases. Results: There were 155 patients in the survey, with 20 of these receiving nonspinal injections. Of the remaining 135 patients who underwent spinal injections, only 10 received conscious sedation. On average, 14.2% experienced severe pain during spinal injections, whereas 20% experienced severe pain with nonspinal injections. Though few patients received conscious sedation, most of these (60%) experienced high levels of pain. There was no correlation between level of procedural pain with age, gender, ethnicity, preprocedure pain level, procedure type, tobacco use, or medication type used. Conclusions: The majority of patients who undergo nonsedated interventional pain management procedures do not experience severe pain. There is a small but appreciable group of subjects who seem to experience severe pain that cannot be correlated to any particular clinical characteristic in a standard patient evaluation. Even with standard conscious sedation, there is no clear best method to ensure patient comfort for this high-pain level group.