Pain
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The mechanisms whereby deposition of monosodium urate (MSU) crystals in gout activates nociceptors to induce joint pain are incompletely understood. We tried to reproduce the signs of painful gouty arthritis, injecting into the knee joint of rats suspensions containing amorphous or triclinic, needle MSU crystals. The magnitude of MSU-induced inflammation and pain behavior signs were correlated with the changes in firing frequency of spontaneous and movement-evoked nerve impulse activity recorded in single knee joint nociceptor saphenous nerve fibers. ⋯ Intra-articular injection of hyaluronan (HA, Synvisc), a high-MW glycosaminoglycan present in the synovial fluid with analgesic effects in osteoarthritis, significantly reduced MSU-induced behavioral signs of pain and decreased the enhanced joint nociceptor activity. Our results support the interpretation that pain and nociceptor activation are not triggered by direct mechanical stimulation of nociceptors by MSU crystals, but are primarily caused by the release of excitatory mediators by inflammatory cells activated by MSU crystals. Intra-articular HA decreased behavioral and electrophysiological signs of pain, possibly through its viscoelastic filtering effect on the mechanical forces acting over sensitized joint sensory endings and probably also by a direct interaction of HA molecules with the transducing channels expressed in joint nociceptor terminals.
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Review Meta Analysis
The effectiveness of online pain resources for health professionals: a systematic review with subset meta-analysis of educational intervention studies.
Online educational interventions are increasingly developed for health professionals and students, although graduate and undergraduate medical curricula often contain limited information about how to assess and manage pain. This study reviews the literature on the effectiveness of pain-related online educational resources. Studies were identified through a search of Medline, PsychINFO, Web of Science, CINAHL, PubMed, Scopus, Cochrane Library, Google Scholar, and OpenGrey databases. ⋯ Although online educational resources show promise in improving learner knowledge, considerable heterogeneity exists between studies in quality, design, educational content, and outcomes. Furthermore, methodologically robust RCTs are required to establish the effectiveness of online educational interventions and a greater understanding of the key features of successful online resources, including cognitive interactivity. Few studies assessed health outcomes for patients, remaining a major priority for future investigations.
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Interdisciplinary multimodal pain therapy (IMPT) is a biopsychosocial treatment approach for patients with chronic pain that comprises at least psychological and physiotherapeutic interventions. Core outcome sets (COSs) are currently developed in different medical fields to standardize and improve the selection of outcome domains, and measurement instruments in clinical trials, to make trial results meaningful, to pool trial results, and to allow indirect comparison between interventions. The objective of this study was to develop a COS of patient-relevant outcome domains for chronic pain in IMPT clinical trials. ⋯ The panel agreed on the following 8 domains to be included into the COS for IMPT: pain intensity, pain frequency, physical activity, emotional wellbeing, satisfaction with social roles and activities, productivity (paid and unpaid, at home and at work, inclusive presentism and absenteeism), health-related quality of life, and patient's perception of treatment goal achievement. The complexity of chronic pain in a biopsychosocial context is reflected in the current recommendation and includes physical, mental, and social outcomes. In a subsequent step, measurement instruments will be identified via systematic reviews.
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Randomized Controlled Trial
Psychological flexibility mediates the effect of an online-based acceptance and commitment therapy for chronic pain: an investigation of change processes.
One way to improve treatment effects of chronic pain is to identify and improve control over mechanisms of therapeutic change. One treatment approach that includes a specific proposed mechanism is acceptance and commitment therapy (ACT) with its focus on increasing psychological flexibility (PF). The aim of the present study was to examine the role of PF as a mechanism of change in ACT. ⋯ Structural equation modelling analyses revealed that changes in PF significantly mediated pretreatment to follow-up changes in all outcomes in the intervention groups compared with waitlist (standardized estimates ranged from I0.16I to I0.69I). Global model fit yielded modest but acceptable results. Findings are consistent with the theoretical framework behind ACT and contribute to growing evidence, supporting a focus on PF to optimize treatment effects.
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This study aimed to (1) characterise long-term profiles of back pain across adulthood and (2) examine whether childhood risk factors were associated with these profiles, using data from 3271 participants in the Medical Research Council National Survey of Health and Development. A longitudinal latent class analysis was conducted on binary outcomes of back pain at ages 31, 36, 43, 53, 60 to 64, and 68 years. Multinomial logistic regression models were used to examine associations between selected childhood risk factors and class membership; adjusted for sex, adult body size, health status and behaviours, socioeconomic position, and family history of back pain. ⋯ Abdominal pain and poorest housing quality were also associated with an increased likelihood of mid-adulthood onset pain. These findings suggest that there are different long-term profiles of back pain, each of which is associated with different early life risk factors. This highlights the potential importance of early life interventions for the prevention and management of back pain.