Pain
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Peripheral nerve regeneration is associated with pain in several preclinical models of neuropathic pain. Some neuropathic pain conditions and preclinical neuropathic pain behaviors are improved by sympathetic blockade. In this study, we examined the effect of a localized "microsympathectomy," ie, cutting the gray rami containing sympathetic postganglionic axons where they enter the L4 and L5 spinal nerves, which is more analogous to clinically used sympathetic blockade compared with chemical or surgical sympathectomy. ⋯ Microsympathectomy reduced functional regeneration as measured by myelinated action potential propagation through the injury site and denervation-induced atrophy of the tibial-innervated gastrocnemius muscle at day 10. Microsympathectomy plus CCL2 knockdown had behavioral effects similar to microsympathectomy alone. The results show that local sympathetic effects on neuropathic pain may be mediated in a large part by the effects on expression of CCL2, which in turn regulates the regeneration process.
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Pragmatic randomised clinical trials aim to directly inform clinical or health policy decision making. Here, we systematically review methods and design of pragmatic trials of pain therapies to examine methods, identify common challenges, and areas for improvement. Seven databases were searched for pragmatic randomised controlled clinical trials that assessed pain treatment in a clinical population of adults reporting pain. ⋯ They were lowest for patient recruitment methods and extent of follow-up measurements and appointments. Current practice in pragmatic trials of pain treatments can be improved in areas such as patient recruitment and reporting of methods, analysis, and interpretation of data. These improvements will facilitate translatability to other real-world settings-the purpose of pragmatic trials.
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Endocannabinoid (eCB) levels fluctuate in inflammatory conditions and as such may take part in endometriosis-associated pain or even in endometriosis pathogenesis. In this case-control (23 cases and 19 controls) study, targeted lipids were measured in the serum and peritoneal fluid collected during laparoscopy. Endometriosis was confirmed histologically. ⋯ Specifically, women suffering from noncyclic abdominal pain were characterized by a higher 2-AG level in the peritoneal fluid throughout the menstrual cycle, whereas women suffering from dysmenorrhea had higher 2-AG levels and lower AEA levels during the proliferative phase alone. In addition, 2-AG positively correlated with prostaglandin E2 (PGE2), and the ratio AEA/2-AG positively correlated with defensins, suggesting a possible link between endocannabinoids system and inflammatory pain. The results of the current study indicate that the eCB system may play a role in endometriosis-associated pain, but additional studies are needed to investigate the causal relationship.
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The net effects of prescribing initiatives that encourage dose reductions are uncertain. We examined whether rapid dose reduction after high-dose chronic opioid therapy (COT) associates with suicide, overdose, or other opioid-related adverse events. This retrospective cohort study included Oregon Medicaid recipients with high-dose COT. ⋯ By contrast, discontinuation or dose reduction reduced the risk of overdose compared with those with a stable or increasing dose (aHR 0.36-0.62, 95% CI 0.20-0.94). Patients with an abrupt discontinuation were more likely to overdose on heroin (vs. prescription opioids) than patients in other groups (P < 0.0001). Our study suggests that patients on COT require careful risk assessment and supportive interventions when considering opioid discontinuation or continuation at a high dose.
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Chronic postsurgical pain (CPSP) and disability after cardiothoracic surgery are highly prevalent and difficult to treat. Researchers have explored a variety of presurgical risk factors for CPSP and disability after cardiothoracic surgery, including one study that examined distress from bodily sensations. The current prospective, longitudinal study sought to extend previous research by investigating presurgical distress about bodily sensations as a risk factor for CPSP and disability after cardiothoracic surgery while controlling for several other potential psychosocial predictors. ⋯ Multinomial logistic regression analyses were conducted to evaluate the degree to which presurgical measures predicted pain outcomes 6 months after surgery. The results showed that CPSP intensity was significantly predicted by age and presurgical scores on the Symptom Checklist-90-Revised Somatization subscale (Nagelkerke R2 = 0.27, P < 0.001), whereas chronic pain disability was only predicted by presurgical Symptom Checklist-90-Revised Somatization scores (Nagelkerke R2 = 0.29, P < 0.001). These findings demonstrate that presurgical distress over bodily sensations predicts greater chronic pain intensity and disability 6 months after cardiothoracic surgery and suggest that presurgical treatment to diminish such distress may prevent or minimize CPSP intensity and disability.