Pain
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Little is known about risk factors for emergency department (ED) attendance for chronic pain (CP) management and the relative service burden. We examined ED utilisation in patients with CP, identified risk factors associated with attendance for chronic musculoskeletal pain (CMP), and estimated the comparative cost of treatment. The study cohort comprised a random sample of 3700 adults from the general population in Tayside, Scotland. ⋯ Characteristics protective of ED attendance for CMP were: being in receipt of strong opioids (OR = 0.21); transitioning from nonopioid to opioid analgesics (OR = 0.25); recent analgesic dose increases (OR = 0.24); and being prescribed tricyclic antidepressants (OR = 0.10), benzodiazepines (OR = 0.46), or hypnotics (OR = 0.45). Chronic musculoskeletal pain was one of the most expensive conditions to treat (£17,680 [∼$22,668] per annum), conferring a substantial burden on ED services. Improved understanding of the risk/protective factors could inform healthcare redesign to reduce avoidable ED attendances for CMP management.
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Low back pain is a leading cause of disability globally. It is a common reason for presentation to the emergency department where opioids are commonly prescribed. This is a retrospective cohort study of opioid-naive adults with low back pain presenting to 1 of 4 emergency departments in Nova Scotia. ⋯ First prescription average >90 morphine milligram equivalents/day (odds ratio 1.6, 95% confidence interval 1.0-2.6) and greater than 7-day supply (1.9, 1.1-3.1) were associated with prolonged opioid use in adjusted models. We found evidence of declining opioid prescriptions over the study period, but that 24.3% of first opioid prescriptions in 2016 would not have aligned with current guideline recommendations. Our study provides evidence to support a cautious approach to prescribing in opioid-naive populations.
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The nucleus accumbens (NAc) and the ventral tegmental area (VTA) are critical hubs in the brain circuitry controlling chronic pain. Yet, how these 2 regions interact to shape the chronic pain state is poorly understood. Our studies show that in mice, spared nerve injury (SNI) induced alterations in the functional connectome of D2-receptor expressing spiny projection neurons in the core region of the NAc-enhancing connections with prelimbic cortex and weakening them with basolateral amygdala. ⋯ By contrast, chemogenetic enhancement of activity in VTA dopaminergic neurons projecting to the medial shell of the NAc selectively suppressed tactile allodynia in SNI mice. These results suggest that SNI induces regionally specific alterations in VTA dopaminergic signaling in the NAc to promote environmental reengagement after injury. However, countervailing, homeostatic mechanisms limit these adaptive changes, potentially leading to the chronic pain state.
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Under some conditions, people persist in their attempts to control their pain even when no such control is possible. Theory suggests that such pain-control attempts arise from actual pain experiences. Across 3 experiments we examined how (1) losing control over pain and (2) instructions concerning pain, moderated pain-control attempts. ⋯ Instead, participants lost control over pain because of an unannounced change in the learning task. Results indicated that when participants lost control over pain, they generally stuck to the previously effective pain-control strategy, and that this tendency was larger if they received instructions from others than when they developed a strategy by themselves. These findings suggest that when pain is no longer controllable, very persistent pain-control attempts might be the result of adherence to previously effective pain-control instructions.