Pain
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Randomized Controlled Trial Clinical Trial
Topical capsaicin selectively attenuates heat pain and A delta fiber-mediated laser-evoked potentials.
Cutaneous stimulation with CO2 laser pulses activates A delta of nociceptive afferents and evokes late cerebral potentials (LEPs), the amplitude of which correlates parametrically with the perceived magnitude estimation of laser pulses. Capsaicin is known to desensitize the nociceptive terminals of C fibers. In this double-blind, vehicle-controlled experiment, we tested the hypothesis that topical capsaicin would inactivate A delta afferents and lead to an attenuation of the LEPs. ⋯ It indicated that topical capsaicin caused a definite functional and reversible inactivation of A delta nociceptive afferent transmission. The decline in the magnitude estimation of laser pulses concomitantly with the attenuation of LEP amplitudes supports the hypothesis that some A delta afferents mediate noxious heat in humans. These findings demonstrate the usefulness of LEP in the physiological evaluation of nociceptive pathways and its potential usefulness in objectively documenting the effect of pharmacological treatment on pain perception.
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of tenoxicam and bromazepan in the treatment of fibromyalgia: a randomized, double-blind, placebo-controlled trial.
Fibromyalgia is a painful syndrome of non-articular origin, predominantly involving muscles, and the commonest cause of chronic widespread musculoskeletal pain. The diversity of therapeutic programs for patients with fibromyalgia reflects both the lack of a known pathophysiology for this disorder and the low efficacy of the current therapies. We studied the efficacy of tenoxicam and bromazepan in the treatment of patients with fibromyalgia. ⋯ At the end of the trial, 17%, 10%, 12%, and 29% of the P, T, B, and TB patients, respectively, had clinical improvement. A statistically significant difference was found only between the T and TB groups. Our data indicate that treatment with tenoxicam + bromazepan can be effective for some patients with fibromyalgia, but the differences with the placebo group were neither clinically nor statistically significant.
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Accuracy and errors in judges' attempts to differentiate facial expressions that displayed genuine pain, no pain or were dissimulated (i.e., masked and exaggerated) were examined. Judges were informed that misrepresentations in the facial expressions were present and were asked to rate their confidence in classifying these expressions. Detailed, objective coding of the patients' facial reactions (e.g., brow lowering, mouth opening) were related to judges' decisions. ⋯ Judges consistently used rules of thumb based on specific facial cues when making judgments. Certain cues were effectively discriminative. Systematic training in the use of specific cues or the use of articulated decision rules may be helpful in improving judges' accuracy.
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Unrelieved cancer pain remains a significant problem worldwide. Patients receive inadequate analgesia for a variety of complex and multifactorial reasons. Limited availability of opioids secondary to concerns about potential diversion of these medications for illicit use and poor compliance with oral regimens are significant factors in many countries. ⋯ Varying the thickness, diameter, and number of implants provides flexibility in the release rate and duration of release. This implantable opioid delivery device could provide a sustained subcutaneous infusion of hydromorphone to patient with cancer pain in developed and developing nations without pumps, catheters, or extensive outpatient support services. In addition, it should improve compliance and reduce concern regarding illicit diversion of opioids.
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Pain is highly prevalent in individuals with HIV disease, yet is often overlooked as a symptom requiring clinical intervention. We evaluated the adequacy of analgesic management for pain and identified predictors of pain undertreatment in a sample of 366 ambulatory AIDS patients using a prospective cross-sectional survey design. Two hundred and twenty-six of the 366 ambulatory AIDS patients surveyed reported "persistent or frequent" pain over the 2 week period prior to the survey. ⋯ Women, less educated patients, and patients who reported injection drug use as their HIV transmission risk factor were most likely to have received inadequate analgesic therapy. These results demonstrate the alarming degree of undertreatment of pain in ambulatory patients with AIDS, and indicates the need to improve the management of AIDS-related pain in this underserved population. Future research should elucidate the factors that impede adequate pain management in order to overcome obstacles to adequate treatment.