European journal of pain : EJP
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Cutaneous C-fiber afferents show two distinct types of cold sensitivity corresponding to non-noxious and noxious cold sensations. Here, responses to cold stimulation of afferent fibers regenerating in the rat sural nerve were studied in vivo 7-14 days after nerve crush and compared with responses to mechanical and heat stimulation. The physiological stimuli were applied to the sural nerve at or distal to the lesion site. ⋯ They were also heat-sensitive (n=25) and/or mechanosensitive (n=20). These C-fibers were, apart from their cold sensitivity, functionally indistinguishable from C-fibers with mechano- and/or heat sensitivity only. Thus regenerating cutaneous C-fibers show two types of cold sensitivity similar to those observed in intact skin: fibers of one group are predominantly sensitive to cooling, whereas the others are polymodal.
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Review Meta Analysis
Psychosocial predictors and correlates for chronic post-surgical pain (CPSP) - a systematic review.
Chronic post-surgical pain (CPSP) is a serious problem. Incidence as high as 50% has been reported, depending on type of surgery undergone. Because the etiology of chronic pain is grounded in the bio-psychosocial model, physical, psychological, and social factors are implicated in the development of CPSP. ⋯ Other factors were determined to have either unlikely (grade of association=3) or inconclusive (grade of association=2) correlations. In addition, results were examined in light of the type of surgery undergone. This review is intended as a first step to develop an instrument for identifying patients at high risk for CPSP, to optimize clinical pain management.
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Randomized Controlled Trial Comparative Study
Gastrointestinal symptoms under opioid therapy: a prospective comparison of oral sustained-release hydromorphone, transdermal fentanyl, and transdermal buprenorphine.
The purpose of this trial was to evaluate the effect of long-term treatment with oral sustained-release hydromorphone, transdermal fentanyl, and transdermal buprenorphine on nausea, emesis and constipation. ⋯ Gastrointestinal symptoms of cancer pain patients undergoing an opioid therapy are related to multifactorial causes. Transdermal opioids showed no benefit over oral controlled-release hydromorphone with regard to gastrointestinal symptoms. The conversion ratios for transdermal fentanyl, transdermal buprenorphine, and oral hydromorphone did not accord to the literature, because of differing occurrences of opioid tolerance after long-term therapy.
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Loss of function is usually considered the major consequence of spinal cord injury (SCI). However, pain severely compromises the quality of life in nearly 70% of SCI patients. The principal aim of this study was to assess the contribution of Tumor necrosis factor alpha (TNF-alpha) to SCI pain. ⋯ Furthermore, minocycline decreased the expression of noxious-stimulation-induced c-Fos, suggesting an effect on evoked neuronal activity. This study demonstrates that TNF-alpha plays an important role in the establishment of neuropathic pain following SCI, seemingly dependent on microglial activation. Pharmacological targeting of TNF-alpha may offer therapeutic opportunities for treating SCI pain.
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Randomized Controlled Trial Comparative Study
Postoperative analgesia and early rehabilitation after total knee replacement: a comparison of continuous low-dose intravenous ketamine versus nefopam.
The effects of nefopam and ketamine on pain control and rehabilitation after total knee replacement were compared in a prospective, double blinded study. Seventy-five patients were randomly assigned to receive a 0.2mg kg(-1) bolus of nefopam or ketamine, followed by a 120microg kg(-1) h(-1) continuous infusion until the end of surgery, and 60microg kg(-1) h(-1) until the second postoperative day, or an equal volume of saline considered as placebo. Pain scores measured on a visual analog scale at rest and on mobilization, and patient-controlled intravenous morphine consumption, were assessed during 48h. ⋯ Ketamine improved knee flexion on post operative day 3 (59 degrees [33-63] vs. 50 degrees [47-55] and 50 degrees [44-55] in ketamine, placebo and nefopam groups, respectively, p<0.0002) and decreased the delay to flex the knee at 90 degrees (9.1+/-4.2 vs. 12.3+/-4.0 days, in ketamine and placebo groups, respectively, p=0.01). Ketamine produces opioid-sparing, decreases pain intensity, and improves mobilization after total knee replacement. Nefopam achieves less significant results in that circumstances.