Pain
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Despite well-documented racial disparities in prescribing opioid medications for pain, little is known about whether there are disparities in the monitoring and follow-up treatment of patients who are prescribed opioid medications. We conducted a retrospective cohort study to examine whether there are racial differences in the use of recommended opioid monitoring and follow-up treatment practices. Our sample included 1646 white and 253 black patients who filled opioid prescriptions for noncancer pain for ≥ 90 consecutive days at the Veterans Affairs Pittsburgh Healthcare System pharmacy in fiscal years 2007 and 2008. ⋯ Among those who had at least 1 urine drug test, black patients were subjected to more tests, especially if they were on higher doses of opioids. Compared with white patients, black patients were less likely to be referred to a pain specialist and more likely to be referred for substance abuse assessment. Addressing disparities in opioid monitoring and follow-up treatment practices may be a previously neglected route to reducing racial disparities in pain management.
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The interaction between intensity of nociceptive stimuli and cognitive load in a concomitant task is still a challenging and complex topic. Here, we investigated the interaction between top-down factors (i.e., perceptual load), induced by a visual task, and bottom-up factors (i.e., intensity of nociceptive stimuli that implicitly modifies saliency of input). Using a new experimental paradigm, in which perceptual load is varied while laser heat stimuli of different intensities are processed; we show a significant interaction between intensity of nociceptive stimuli and perceptual load on both pain ratings and task performance. ⋯ However, under this condition, task performance was impaired, regardless of interindividual differences in motivation and pain catastrophizing. Thus, we showed that pain ratings can be reduced by increasing the load of attentional resources at the perceptual level of a non-pain-related task. Nevertheless, the disruptive effect of highly intensive nociceptive stimuli on the performance of the perceptual task was evident only under high load.
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The nociceptive transmission under pathological chronic pain conditions involves transcriptional and/or translational alteration in spinal neurotransmitters, receptor expressions, and modification of neuronal functions. Studies indicate the involvement of microRNA (miRNA) - mediated transcriptional deregulation in the pathophysiology of acute and chronic pain. In the present study, we tested the hypothesis that long-term cross-organ colonic hypersensitivity in neonatal zymosan-induced cystitis is due to miRNA-mediated posttranscriptional suppression of the developing spinal GABAergic system. ⋯ An increase in miR-181a concomitantly resulted in significant down-regulation of GABA(Aα-1) receptor subunit gene and protein expression in adult spinal cords from rats with neonatal cystitis. Intrathecal administration of the GABA(A) receptor agonist muscimol failed to attenuate the viscero-motor response (VMR) to colon distension in rats with neonatal cystitis, whereas in adult zymosan-treated rats the drug produced significant decrease in VMR. These results support an integral role for miRNA-mediated transcriptional deregulation of the GABAergic system in neonatal cystitis-induced chronic pelvic pain.
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Persistent postsurgical pain (PPSP) is a frequent and often disabling complication of many surgical procedures. Nerve injury-induced neuropathic pain (NeuP) has repeatedly been proposed as a major cause of PPSP. However, there is a lack of uniformity in NeuP assessment across studies, and the prevalence of NeuP may differ after various surgeries. ⋯ In patients with PPSP after groin hernia repair, the prevalence of NeuP was 31%, and after total hip or knee arthroplasty it was 6%. The results suggest that the prevalence of NeuP among PPSP cases differs in various types of surgery, probably depending on the likelihood of surgical iatrogenic nerve injury. Because of large methodological variability across studies, a more uniform approach is desirable in future studies for evaluating persistent postsurgical NeuP.