The journal of pain : official journal of the American Pain Society
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We developed a rat model of oral cancer pain by inoculating cancer cells into the lower gingiva. A squamous cell carcinoma (SCC) derived from Fisher rats, SCC-158, was inoculated into the subperiosteal tissue on the lateral side of the lower gingiva in male Fisher rats. Inoculation of cancer cells induced marked mechanical allodynia and thermal hyperalgesia in the ipsilateral maxillary and mandibular nerve area. Infiltration of the tumor cells into the mandible and the completely encompassed inferior alveolar nerve was observed. Calcitonin gene-related peptide (CGRP)-, substance P (SP)-, ATP receptor (P2X(3))-, and capsaicin receptor (TRPV1)-immunoreactive cells strikingly increased in the small-cell group of trigeminal ganglia (TGs) after tumor cell inoculation. The TRPV1-immunoreactive cells also increased in the medium- and large-cell groups. Retrograde tracing combined with immunofluorescence techniques revealed the increased expression of peptides and the receptors in maxillary nerve afferent neurons. These results suggest that inoculation of SCC cells into the lower gingiva produces mechanical allodynia and thermal hyperalgesia, indicating the establishment of a novel rat model of oral cancer pain. Increased expression of CGRP, SP, P2X(3), and TRPV1 in the TG may be involved in the behavioral changes in this model. ⋯ To clarify the mechanisms of oral cancer pain, we examined the expression of calcitonin gene-related peptide, substance P, ATP receptor P2X(3), and capsaicin receptor TRPV1 in trigeminal ganglia. Characterizations of these molecular systems which mediate pain perception are important to develop novel clinical tools for promoting relief of oral cancer pain.
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Patients presenting to an emergency department (ED) with painful conditions continue to experience significant delay to analgesia. It remains unclear whether demographic and clinical factors are associated with this outcome. The objectives of this study were to determine 1) the proportion of patients that require parenteral opiate analgesia for pain in an ED and who receive the opiate in less than 60 minutes; and 2) whether any factors are predictive for the first dose of analgesia being delayed beyond 60 minutes. A retrospective cohort study with descriptive and comparative data analysis was conducted. Over a 3-month period, the medical record of every patient receiving parenteral opiates in a tertiary emergency department was reviewed and analyzed. Of 857 patients, 451 (52.6%) received analgesia in less then 60 minutes. Multiple demographic and clinical factors are associated with statistically significant delay to analgesia, including age, triage code, seniority of treating doctor, diagnosis, and disposition from the ED. ⋯ A considerable proportion of patients suffer delay to analgesia. Identifiable factors associated with a delay to analgesia exist. There is potential for clinicians to develop strategies to address the population in emergency departments at risk for delay to analgesia.
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Randomized Controlled Trial Comparative Study
A comparison of conventional pain coping skills training and pain coping skills training with a maintenance training component: a daily diary analysis of short- and long-term treatment effects.
Pain coping skills training (PCST) has been shown to produce immediate improvements in pain and disability in rheumatoid arthritis (RA). However, some patients have difficulty maintaining these gains. This study compared a conventional PCST protocol with a PCST protocol that included maintenance training (PCST/MT). Patients with RA (n = 167) were randomly assigned to either conventional PCST, PCST/MT, arthritis education control, or standard care control. Daily data were collected on joint pain, coping, coping efficacy, and mood. Multilevel analyses showed that at posttreatment, conventional PCST was superior to all other conditions in joint pain, coping efficacy, and negative mood, whereas PCST/MT was superior to all other conditions in emotion-focused coping and positive mood. At 18 months follow-up, both PCST conditions were superior to standard care in joint pain and coping efficacy. Interpretation of follow-up outcomes was limited by higher dropout rates in the 2 PCST groups. For RA, a maintenance training component does not appear to produce significant improvements over conventional PCST. ⋯ This article reports a trial evaluating a conventional pain coping skills training protocol and a similar protocol that included a maintenance training component. Overall, results indicate similar results for both the conventional and the modified protocols.
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The objective of this retrospective study was to test the validity and reliability of a scoring tool (the DIRE Score), for use by clinicians, that predicts which chronic noncancer pain patients will have effective analgesia and be compliant with long-term opioid maintenance treatment. DIRE scores were assigned to 61 cases from the pain center's databases. These cases were abstracted into vignettes that were reviewed and scored by 6 physicians. Repeat scoring was carried out on a subset of 30 vignettes after 2 weeks. The main outcome measures were: global impression of compliance and efficacy as indicated in the medical record and by interview with the patient's treating clinician; and final disposition, ie, whether or not opioids were continued or discontinued at the time of last clinical documentation. Internal consistency of the factors making up the DIRE Score was high (Cronbach's alpha = .80). Sensitivity and specificity of the DIRE Score for predicting patient compliance were 94% and 87%, respectively. For efficacy, sensitivity and specificity were 81% and 76%. For disposition, the sensitivity and specificity were 86% and 73%. Intraclass correlation was 0.94 for interrater reliability and 0.95 for intrarater reliability. ⋯ Public controversy about the use of long-term opioids for chronic pain fuels physician ambivalence about the prescribing process. In this initial retrospective study, validity and reliability of the DIRE Score are demonstrated. The score correlated well with measures of patient compliance and efficacy of long-term opioid therapy.
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Chronic pain following breast cancer surgery is associated with decreased health-related quality of life and is a source of additional psychosocial distress in women who are already confronting the multiple stresses of cancer. Few prospective studies have identified risk factors for chronic pain following breast cancer surgery. Putative demographic, clinical, and psychosocial risk factors for chronic pain were evaluated prospectively in 95 women scheduled for breast cancer surgery. In a multivariate analysis of the presence of chronic pain, only younger age was associated with a significantly increased risk of developing chronic pain 3 months after surgery. In an analysis of the intensity of chronic pain, however, more invasive surgery, radiation therapy after surgery, and clinically meaningful acute postoperative pain each independently predicted more intense chronic pain 3 months after surgery. Preoperative emotional functioning variables did not independently contribute to the prediction of either the presence or the intensity of chronic pain after breast cancer surgery. These findings not only increase understanding of risk factors for chronic pain following breast cancer surgery and the processes that may contribute to its development but also provide a basis for the development of preventive interventions. ⋯ Clinical variables and severe acute pain were risk factors for chronic pain following breast cancer surgery, but psychosocial distress was not, which provides a basis for hypothesizing that aggressive management of acute postoperative pain may reduce chronic pain.