Treatment Disparities in Hispanic Patients with Chronic Pain: An Evidence-Based Narrative Review.

PURPOSE OF REVIEW: The purpose of this narrative review is to summarize healthcare disparities experienced by Hispanic and Latino/Latinx patients with chronic pain, evaluate the existing literature exploring the specific therapeutic inequities affecting this patient population, and identify gaps in the literature requiring future study. RECENT FINDINGS: Hispanic and Latino/Latinx patients experience disparities in chronic pain management. They are less likely to be prescribed pharmacologic therapies, including non-steroidal anti-inflammatory drugs and opioids. Hispanic and Latino/Latinx patients are also less likely to receive spinal cord stimulators and may be charged higher costs for them. There are no published studies specifically assessing Hispanic and Latino/Latinx patients' utilization and outcomes from other common interventional pain procedures (e.g., epidural steroid injections, radiofrequency ablation). Limited data suggest non-pharmacologic treatments, such as cognitive behavioral therapy and complementary/integrative health modalities, might have more benefit for this population, potentially because of greater utilization. Hispanic and Latino/Latinx patients experience disparities in chronic pain management. There is a paucity of data available pertaining specifically to pain-related outcomes and the utilization of pain treatment modalities, especially in regard to interventional procedures. Additional research is urgently needed in order to understand the full extent of these disparities and develop solutions to provide more equitable care.

Peripheral Nerve Stimulation for Low Back Pain: A Systematic Review.

PURPOSE OF REVIEW: Low back pain (LBP) is a prevalent condition that is associated with diminished physical function, poor mental health outcomes, and reduced quality of life. Peripheral nerve stimulation (PNS) is an emerging modality that has been utilized to treat LBP. The primary objective of this systematic review is to appraise the level of evidence on the efficacy of PNS for treatment of LBP. RECENT FINDINGS: Twenty-nine articles were included in this systematic review, consisting of 828 total participants utilizing PNS as the primary modality for LBP and 173 participants using PNS as salvage or adjunctive therapy for LBP after SCS placement. Different modalities of PNS therapy were reported across studies, including conventional PNS systems stimulating the lumbar medial branch nerves, peripheral nerve field stimulation (PNFS), and restorative neuromuscular stimulation of the multifidus muscles. All studies consistently reported positive modest to moderate improvement in pain intensity with PNS therapy when comparing baseline pain intensity to each study's respective primary follow-up period. There was a very low GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) quality of evidence supporting this finding. Inconsistency was present in some comparative studies that demonstrated no difference between PNS therapy versus control cohorts (sham or SCS therapy alone), which therefore highlighted the potential for placebo effect. This systematic review highlights that PNS, PNFS, and neuromuscular stimulation may provide modest to moderate pain relief in patients with LBP, although evidence is currently limited due to risk of bias, clinical and methodological heterogeneity, and inconsistency in data.

Evidence-Based Treatment of Pain in Chemotherapy-Induced Peripheral Neuropathy.

PURPOSE OF REVIEW: Chemotherapy-induced peripheral neuropathy (CIPN) is a debilitating and often painful condition that occurs after administration of chemotherapeutic agents. The primary objective of this systematic review was to appraise the literature on conservative, pharmacological, and interventional treatment options for CIPN pain. RECENT FINDINGS: There is level I evidence supporting modest to moderate improvement in CIPN pain from duloxetine treatment, as well as short-term modest improvement from physical therapy and acupuncture. Although opioid and cannabis administration may provide short-term modest improvement, administration is commonly limited by side effects. Generally, most studies reported no clinical benefit from yoga, topical neuropathic agents, gabapentinoids, and tricyclic antidepressants. Evidence is currently equivocal for scrambler therapy and transcutaneous electrical nerve stimulation. Finally, evidence on neuromodulation options is limited to mostly case reports/series and one observational study highlighting moderate improvement with auricular nerve stimulation. This systematic review provides an overview of conservative, pharmacologic, and interventional treatment modalities for CIPN pain. Furthermore, it provides a level of evidence and degree of recommendation based on the United States Preventive Services Task Force (USPSTF) criteria for each specific treatment modality.

Peripheral Nerve Stimulation for the Treatment of Postamputation Pain: A Systematic Review.

ABSTRACT: Despite numerous first-line treatment interventions, adequately managing a patient's postamputation pain can be difficult. Peripheral nerve stimulation has emerged as a safe neuromodulatory intervention that can be used for many etiologies of chronic pain. We performed a systemic review to appraise the evidence of peripheral nerve stimulation use for improvement in postamputation pain. This was performed in Ovid, Cochrane databases, OVID, Scopus, Web of Science Core Collection, and PubMed. The primary outcome was improvement in postamputation pain after use of peripheral nerve stimulation. Secondary outcomes included improvements in functional status, opioid usage, and mood. Data extraction and risk of bias assessments were performed independently in a blinded manner. Of the 989 studies identified, 13 studies were included consisting of three randomized control trials, seven observational studies, and three case series. While large heterogeneity limited definitive conclusions, the included studies generally demonstrated favorable outcomes regarding pain reduction. Each included study that used an objective pain scale demonstrated clinically significant pain improvements. Per the Grading of Recommendations, Assessment, Development, and Evaluations criteria, there is very low-quality Grading of Recommendations, Assessment, Development, and Evaluations evidence supporting that peripheral nerve stimulation is associated with improvements in pain intensity for postamputation pain. Future prospective, comparative, and well-powered studies assessing the use of peripheral nerve stimulation for postamputation pain are warranted.

Mechanism of Action of Peripheral Nerve Stimulation.

PURPOSE OF REVIEW: The number of applications for peripheral nerve stimulation (PNS) in the pain management field is ever-growing. With the increasing number of clinical applications for peripheral nerve stimulation, the purpose of this article is to review the mechanism of action surrounding PNS, the recent literature from January 2018 to January 2021, and pertinent clinical outcomes. RECENT FINDINGS: The authors searched articles identified from PubMed (January 2018-January 2021), Cochrane Central Register of Controlled Trials databases (January 2018-January 2021), and Scopus (January 2018-January 2021) databases, and manually searched references of identified publications. Broad MeSH terms and Boolean operators were queried in each search, including the following terms and their respective synonyms: peripheral nerve stimulation, mechanism of action, biochemical pathway, and pain pathway. 15 consensus articles were selected for in-depth review and inclusion for qualitative analysis. PNS may activate and modulate higher central nervous system (CNS) centers, including the dorsal lateral prefrontal cortex, somatosensory cortex, anterior cingulate cortex, and parahippocampal areas. Neuromodulatory effects from PNS may also extend into the spinal columns. Also, PNS may lead to changes in endogenous neurotransmitters and affect the plasticity of NMDA pathways.

Intermittent bolus versus continuous infusion techniques for local anesthetic delivery in peripheral and truncal nerve analgesia: the current state of evidence.

Manually delivered intermittent bolus (MIB) and programmable intermittent bolus (PIB), alternatives to continuous infusion (CI), involve administering a set volume of solution at a set interval of time. The benefits of intermittent bolus techniques in truncal and peripheral nerve blockade (TPNB) are unclear, and studies have largely demonstrated conflicting results. Using MEDLINE, Embase, Google Scholar, and the Cochrane Library, we conducted an evidenced-based review of published randomized controlled trials comparing intermittent bolus and CI methods in TPNB. In total, 13 randomized controlled trials were identified and evaluated. Outcomes data addressed in these studies included assessments of pain, opioid and local anesthetic consumption, patient satisfaction, adverse events, and physical therapy metrics. The overall quality of current evidence was found to be low given the small sample sizes, heterogeneity of data, and the variations in intermittent bolus techniques between studies. At this time, we found limited supportive data to endorse MIB or PIB over CI in TPNB. While unable to provide data-driven conclusions for local anesthetic delivery methods at this time, we propose that future studies and quantitative analysis between techniques should be on an anatomic, site-specific basis, with greater focus on evaluation of opioid use, adverse events, patient satisfaction, and rehabilitative metrics.