The journal of pain : official journal of the American Pain Society
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Clinical Trial
The relationship between sensory loss and persistent pain 1 year after breast cancer surgery.
Moderate to severe persistent pain after breast cancer surgery (PPBCS) affects 10 to 20% of the patients. Sensory dysfunction is often concomitantly present suggesting a neuropathic pain state. The relationship between various postoperative pain states and sensory dysfunction has been examined using quantitative sensory testing (QST), but only 2 smaller studies have examined PPBCS and sensory dysfunction in the surgical area. ⋯ Increased hypoesthesia areas were associated with pain at rest as well as during movement (P = .0001). Pain during movement was associated with a side-to-side difference of 140% (P = .001) for tactile detection threshold and 40% (P = .01) for mechanical pain threshold as well as increased thermal thresholds in the axilla (P > .001). Logistic regression models controlling for confounders showed larger areas of hypoesthesia as a significant risk factor, odds ratio 1.85 per 100 cm2 for pain at rest and odds ratio 1.36 per 100 cm2 for pain during movement.
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Resilience, a characteristic that enhances adaptation in response to stressful events, is a positive psychological factor that can predict and modulate health outcomes. However, resilience is rarely considered in pain research. Conversely, negative psychological factors (eg, anxiety, depression) are known to be related to the affective dimension of pain. ⋯ Furthermore, in individuals with higher anxiety scores, resilience was protective against higher pain affect. This highlights the importance of resilience, a positive psychological factor, in the affective dimension of pain. This study is the first to assess a positive psychological factor and experimental pain affect, and has the potential to improve prediction of and treatment strategies for clinical pain.
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Claims are made for the validity of some self-report pain scales for 3- and 4-year-old children, but little is known about their ability to use such tools. This systematic review identified self-report pain intensity measures used with 3- and/or 4- year-old participants (3-4yo) and considered their reliability and validity within this age span. The search protocol identified research articles that included 3-4yo, reported use of any pain scale, and included self-reported pain intensity ratings. A total of 1,590 articles were screened and 617 articles met inclusion criteria. Of the included studies, 98% aggregated self-report data for 3-4yo with data for older children, leading to overestimates of the reliability and validity of self-report in the younger age group. In the 14 studies that provided nonaggregated data for 3-4yo, there was no evidence for 3-year-old and weak evidence for 4-year-old children being able to use published self-report pain intensity tools in a valid or reliable way. Preschool-age children have been reported to do better with fewer than the 6 response options offered on published faces scales. Simplified tools are being developed for young children; however, more research is needed before these are adopted. ⋯ Some self-report pain scales have been promoted for use with 3- and 4-year-old children, but this is on the basis of studies that aggregated data for younger and older children, resulting in overestimates of reliability and validity for the preschool-age children. Scales with fewer response options show promise, at least for 4-year-old children.
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Randomized Controlled Trial Multicenter Study
OPRM1 Methylation Contributes to Opioid Tolerance in Cancer Patients.
Cancer patients in pain require high doses of opioids and quickly become opioid-tolerant. Previous studies have shown that chronic cancer pain as well as high-dose opioid use lead to mu-opioid receptor downregulation. In this study we explore downregulation of the mu-opioid receptor gene (OPRM1), as a mechanism for opioid tolerance in the setting of opioid use for cancer pain. ⋯ We focus on 2 main cells within the cancer microenvironment: the cancer cell and the neuron. We show that targeted re-expression of mu-opioid receptor on cancer cells inhibits mechanical and thermal hypersensitivity, and prevents opioid tolerance, in the mouse model. The resultant analgesia and protection against opioid tolerance are likely due to preservation of mu-opioid receptor expression on the cancer-associated neurons.
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Individuals experiencing homelessness in the United States are aging; little is known about chronic pain in this population. In a cross-sectional, population-based study, we interviewed 350 homeless individuals aged 50 years and older to describe pain experienced by older persons experiencing homelessness and to assess factors associated with chronic moderate to severe pain, defined as pain lasting ≥3 months, with a past week average severity score of 5 to 10 (scale 0-10). The median age of participants was 58 years. Participants were predominantly African American (79.6%) and male (77.3%). Overall, 46.8% reported chronic moderate to severe pain. Almost half of participants reported a diagnosis of arthritis (44.3%) and one-third reported symptoms consistent with post-traumatic stress disorder (PTSD; 32.8%). Three-quarters (75.3%) endorsed a personal history of abuse. In multivariate analyses, PTSD (adjusted odds ratio [AOR]: 2.2, 95% confidence interval [CI], 1.4-3.7), arthritis (AOR: 4.8, 95% CI, 3.0-7.8), and history of experiencing abuse (AOR: 2.4, 95% CI, 1.3-4.3) were associated with chronic moderate to severe pain. HIV status, diabetes, depressive symptoms, and substance use were not associated with pain. Clinicians should consider the management of associated mental health conditions and the sequelae of experiencing abuse in the treatment of chronic pain in older adults experiencing homelessness. ⋯ This article describes the prevalence and factors associated with chronic pain in older homeless adults. Almost half report chronic pain, which was associated with PTSD, arthritis, and personal history of abuse. Clinicians should address chronic pain, trauma, and the associated mental health conditions in this high-risk population.