Pain
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The management of severe cancer pain may be problematic in spite of recent advances in pain management. A small percentage of patients with severe intractable pain and/or intractable side effects may require more aggressive interventional pain management strategies including the administration of medications continuously by the intrathecal route. ⋯ Optimal use of these medications requires individual titration to the patient's needs. We describe a case of severe cancer pain where these medications were used successfully by continuous intrathecal infusion and patient controlled intrathecal analgesia.
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Myalgia localized to the neck and shoulder in women is a growing problem both in the general population and in the industrial world. The aim of this study was to investigate the mechanisms involved in work-related myalgia. In 21 women (age, 38.7+/-5.5 years), muscle biopsies were obtained from the upper part of the trapezius and the morphologic and metabolic characteristics of muscle fibres were analyzed. ⋯ Moreover, the proportion of cytochrome c oxidase (COX)-negative fibres seen in the cross-sections was significantly higher in the group of patients which had the higher pain and more painful areas than in the group of patients with lower pain level and painful areas (P < 0.05). The significant increase (P < 0.05) of the size of the type I fibres in trapezius myalgia point to the special strain imposed upon type I muscle fibres during work tasks. Cytochrome oxidase c deficiency which is indicative of an energy crisis within muscle cells and the low capillary to fibre area ratio which might impair oxygen delivery and removal of metabolites in the working muscles are both associated with pain in the trapezius muscle.
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Using the indirect immunofluorescence method, the distribution of cyclic GMP (cGMP) and nitric oxide synthase (NOS) was investigated in lumbar 5 dorsal root ganglia (DRGs) of untreated rats 1, 3 and 7 days following sciatic nerve section (axotomy). Untreated and axotomized (7 days) rats were also studied after perfusion with the NO donor sodium nitroprusside (SNP). Moreover, rats were injected with carrageenan lambda into the unilateral hindpaw and studied after 6 h, 1 day or 2 days. ⋯ Between 15 and 20% of all NOS-positive neuron profiles were surrounded by, or in partial contact with, cGMP-IR satellite cells in controls 1 and 3 days after axotomy, whereas the corresponding figure was around 5% after 7 days. After SNP perfusion 60-70% of all DRG neuron profiles were partly or totally associated with cGMP-positive satellite cell profiles, with no significant difference between untreated and axotomized ganglia. The nerve injury-induced, parallel upregulation of NOS in DRG neurons and cGMP in satellite cells in the initial phase after axotomy suggests an involvement of NO as a signalling molecule between neurons and satellite cells in DRGs, especially after peripheral nerve injury, perhaps exerting a survival effect as recently proposed by Thippeswamy and Morris (1997).
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Variability in patients' response to interventions in pain and other clinical settings is large. Many explanations such as trial methods, environment or culture have been proposed, but this paper sets out to show that the main cause of the variability may be random chance, and that if trials are small their estimate of magnitude of effect may be incorrect, simply because of the random play of chance. This is highly relevant to the questions of 'How large do trials have to be for statistical accuracy?' and 'How large do trials have to be for their results to be clinically valid?' The true underlying control event rate (CER) and experimental event rate (EER) were determined from single-dose acute pain analgesic trials in over 5000 patients. ⋯ Single small trials are unlikely to be correct. If we want to be sure of getting correct (clinically relevant) results in clinical trials we must study more patients. Credible estimates of clinical efficacy are only likely to come from large trials or from pooling multiple trials of conventional (small) size.