The journal of pain : official journal of the American Pain Society
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Review Meta Analysis
Incidence and severity of chronic pain at 3 and 6 months after thoracotomy: meta-analysis.
This systematic review was performed to determine the incidence and the severity of chronic pain at 3 and 6 months after thoracotomy based on meta-analyses. We conducted MEDLINE, Web of Science, and Google Scholar searches of databases and references for English articles; 858 articles were reviewed. Meta-regression analysis based on the publication year was used to examine if the chronic pain rates changed over time. Event rates and confidence intervals with random effect models and Freeman-Tukey double arcsine variance-stabilizing transformation were obtained separately for the incidence of chronic pain based on 1,439 patients from 17 studies at 3 months and 1,354 patients from 15 studies at 6 months. The incidences of chronic pain at 3 and 6 months after thoracotomy were 57% (95% confidence interval [CI], 51-64%) and 47% (95% CI, 39-56%), respectively. The average severity of pain ratings on a 0 to 100 scale at these times were 30 ± 2 (95% CI, 26-35) and 32 ± 7 (95% CI, 17-46), respectively. Reported chronic pain rates have been largely stable at both 3 and 6 months from the 1990s to the present. ⋯ This systematic review's findings suggest that reported chronic pain rates are approximately 50% at 3 and 6 months and have been largely stable from the 1990s to the present. The severity of this pain is not consistently reported. Chronic pain after thoracotomy continues to be a significant problem despite advancing perioperative care.
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Widespread hyperalgesia is well documented among adult patients with irritable bowel syndrome (IBS), but little is known about pain sensitivity among adolescents with IBS. We examined pain sensitivity in 961 adolescents from the general population (mean age 16.1 years), including pain threshold and tolerance measurements of heat (forearm) and pressure pain (fingernail and shoulder) and cold pressor tolerance (hand). Adolescents with IBS symptoms (Rome III criteria) had lower heat pain thresholds compared to controls after adjustments for sex, comorbid pain, and psychological distress (mean difference = -.8 °C; 95% confidence interval [CI] = -1.6 to -.04). Similar results were found for pressure pain threshold at the shoulder (mean difference = -46 kPa; 95% CI = -78 to -13) and fingernail (mean difference = -62 kPa; 95% CI = -109 to -15), and for an aggregate of all 3 threshold measures (z-score difference = -.4; 95% CI = -.6 to -.2), though pressure pain threshold differences were nonsignificant after the final adjustments for psychological distress. No difference of pain tolerance was found between the IBS cases and controls. Our results indicate that adolescents in the general population with IBS symptoms, like adults, have widespread hyperalgesia. ⋯ This is the first report of widespread hyperalgesia among adolescents with IBS symptoms in the general population, with lower pain thresholds found to be independent of sex and comorbid pain. Our results suggest that central pain sensitization mechanisms in IBS may contribute to triggering and maintaining chronic pain symptoms.
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The aim of this study was to assess the economic cost of chronic pain among adolescents receiving interdisciplinary pain treatment. Information was gathered from 149 adolescents (ages 10-17) presenting for evaluation and treatment at interdisciplinary pain clinics in the United States. Parents completed a validated measure of family economic attributes, the Client Service Receipt Inventory, to report on health service use and productivity losses due to their child's chronic pain retrospectively over 12 months. Health care costs were calculated by multiplying reported utilization estimates by unit visit costs from the 2010 Medical Expenditure Panel Survey. The estimated mean and median costs per participant were $11,787 and $6,770, respectively. Costs were concentrated in a small group of participants; the top 5% of those patients incurring the highest costs accounted for 30% of total costs, whereas the lower 75% of participants accounted for only 34% of costs. Total costs to society for adolescents with moderate to severe chronic pain were extrapolated to $19.5 billion annually in the United States. The cost of adolescent chronic pain presents a substantial economic burden to families and society. Future research should focus on predictors of increased health services use and costs in adolescents with chronic pain. ⋯ This cost of illness study comprehensively estimates the economic costs of chronic pain in a cohort of treatment-seeking adolescents. The primary driver of costs was direct medical costs followed by productivity losses. Because of its economic impact, policy makers should invest resources in the prevention, diagnosis, and treatment of chronic pediatric pain.
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Temporomandibular disorder and irritable bowel syndrome are comorbid functional chronic pain disorders of unknown etiology that are triggered/exacerbated by stress. Here we present baseline phenotypic characterization of a novel animal model to gain insight into the underlying mechanisms that contribute to such comorbid pain conditions. In this model, chronic visceral hypersensitivity, a defining symptom of irritable bowel syndrome, is dependent on 3 factors: estradiol, existing chronic somatic pain, and stress. In ovariectomized rats, estradiol replacement followed by craniofacial muscle injury and stress induced visceral hypersensitivity that persisted for months. Omission of any 1 factor resulted in a transient (1 week) visceral hypersensitivity from stress alone or no hypersensitivity (no inflammation or estradiol). Maintenance of visceral hypersensitivity was estradiol dependent, resolving when estradiol replacement ceased. Referred cutaneous hypersensitivity was concurrent with visceral hypersensitivity. Increased spinal Fos expression suggests induction of central sensitization. These data demonstrate the development and maintenance of visceral hypersensitivity in estradiol-replaced animals following distal somatic injury and stress that mimics some characteristics reported in patients with temporomandibular disorder and comorbid irritable bowel syndrome. This new animal model is a powerful experimental tool that can be employed to gain further mechanistic insight into overlapping pain conditions. ⋯ The majority of patients with temporomandibular disorder report symptoms consistent with irritable bowel syndrome. Stress and female prevalence are common to both conditions. In a new experimental paradigm in ovariectomized rats with estradiol replacement, masseter inflammation followed by stress induces visceral hypersensitivity that persists for months, modeling these comorbid pain conditions.
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Accountability has been shown to affect clinical judgments among health care providers in several ways. It may increase a provider's motivation for accuracy, leading to more deliberative judgments, or it may enhance biases that evaluators consistently demonstrate with patients with chronic pain. In this study, medical students read a vignette about a hypothetical patient referred for evaluation of severe low back pain by the Office of Vocational Rehabilitation. Accountability to the patient was either weak (consultative 1-time evaluation) or strong (ongoing primary care provision); societal accountability was either weak (evaluation information as secondary source for disability determination) or strong (evaluation information primary to disability determination). Participants then made judgments regarding validity of the patient's presentation, influence of psychosocial factors on the presentation, and patient's level of pain, distress, and disability, and completed an empathy measure. Results showed that empathy had strong associations with symptom validity and severity judgments. With empathy as a covariate, 3 crossover interactions emerged. Judgments of symptom validity were lower when the 2 forms of accountability were inconsistent (ie, one weak and the other strong) than when they were consistent (ie, both weak or both strong). Likewise, judgments of psychosocial factors and pain/distress/disability were higher under consistent accountability conditions than when accountability conditions were inconsistent. This pattern may imply conflict avoidance or self-protection as a motivation for judgments under inconsistent accountability. This study demonstrated that role demands can affect symptom judgments in complex ways, and that empathy may play both direct and moderating roles. Because physicians are the primary gatekeepers regarding disability determination in both consultative and treating roles, accountability may have significant mediating effects on such determinations. ⋯ This study demonstrated that medical student judgments of pain-related symptoms were strongly associated with their levels of empathic concern. Student judgments of symptom validity and psychosocial influences on patient adjustment were differentially affected by their level of accountability to the patient and society in a disability determination process.