Pain
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Clinical Trial Controlled Clinical Trial
Learning to live with the pain: acceptance of pain predicts adjustment in persons with chronic pain.
When patients find their pain unacceptable they are likely to attempt to avoid it at all costs and seek readily available interventions to reduce or eliminate it. These efforts may not be in their best interest if the consequences include no reductions in pain and many missed opportunities for more satisfying and productive functioning. The purpose of this study was to examine acceptance of pain. ⋯ Regression analyses showed that acceptance of pain predicted better adjustment on all other measures of patient function, independent of perceived pain intensity. These results are preliminary. Further study will be needed to show for whom and under what circumstances, accepting some aspects of the pain experience may be beneficial.
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Myoclonus occasionally occurs in the perioperative setting and in patients on chronic opioid therapy. It appears to be dose-related in a unpredictable manner. Different mechanisms have been proposed to explain the occurrence of a series of neuromuscular disturbances probably sharing final common pathways. ⋯ Adjuvant drugs, such as benzodiazepines or dantrolene may avoid the reduction of the opioid dose while maintaining an acceptable analgesia. Current practice suggests a change in opioid when pain control is not obtained at opioid doses resulting in unacceptable adverse effects, including myoclonus and hyperalgesia. A change in the type of opioid may be useful in patients who develop severe central adverse effects, even if these patients appear to have normal renal function or hydration status.
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Dorsal horn neurons that respond to noxious cold also respond to noxious heat, suggesting the hypothesis that pain evoked by temperature extremes, whether hot or cold, may be processed similarly in the CNS. In this study, we tested perceptual consequences of this hypothesis by comparing characteristics of heat and cold pain, as well as of innocuous warm and cool. Eight healthy subjects performed psychophysical tasks involving hot and cold cutaneous stimuli. ⋯ Perceived stimulus intensity was compared to temperature recordings from intradermal and skin surface thermocouples. Heat pain, cool and warmth appeared to depend on surface temperature, whereas cold pain was related to subcutaneous temperature, suggesting different receptors for noxious heat and noxious cold. These data, combined with results of human brain imaging and primate electrophysiological studies, suggest that the unpleasantness associated with both heat pain and cold pain is processed similarly in the CNS, whereas differential information about stimulus quality is preserved in the cerebral cortex.
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Meta Analysis
Systematic review of factors affecting the ratios of morphine and its major metabolites.
In a systematic review of 57 studies with information on 1232 patients we examined the effect of age, renal impairment, route of administration, and method of analysis on the ratios of morphine-3-glucuronide:morphine (M3G:M) and morphine-6-glucuronide:morphine (M6G:M) and the relative concentrations of M3G and M6G. Across all studies the range of the ratios of metabolites to morphine was wide (0.001-504 for M3G:M, and 0-97 for M6G:M). Neonates produced morphine glucuronides at a lower rate than older children or adults. ⋯ There was no evidence of differences between methods of assay. There was a high correlation between the two glucuronide metabolites in spite of the different situations studied, supporting a single glucuronidating enzyme. Morphine was present in CSF at a fourfold higher concentration than the glucuronide metabolites.