Pain
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This pilot study evaluated the efficacy and side effects of a combination of initial patient-controlled analgesia (PCA) for dose-finding with transdermal fentanyl administration. Twenty inpatients, requiring strong opioids for severe cancer pain, received intravenous fentanyl on an on-demand basis over a 24-h period. The amount of fentanyl administered was then used as a guideline for selecting a suitable transdermal therapeutic system (TTS) on the 2nd day, which remained in place for 3 days. ⋯ Patient compliance and acceptance were excellent. In the absence of severe side effects the main complaints were dryness of the mouth and constipation. Increasing pain intensity and increasing supplementary morphine requirements as well as decreasing plasma fentanyl levels on day 7 may indicate that conversion ratios from intravenous to transdermal administration should be increased or that TTS should be changed earlier.(ABSTRACT TRUNCATED AT 250 WORDS)
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We attempted to develop an experimental animal model for peripheral neuropathic pain. Under sodium pentobarbital anesthesia, both the L5 and L6 spinal nerves (group 1) or the L5 spinal nerve alone (group 2) of one side of the rat were tightly ligated. For comparison, a parallel study was conducted with another group of rats (group 3) which received a partial tight sciatic nerve ligation, a paradigm developed previously as a neuropathy model. ⋯ The present model has two unique features. First, the surgical procedure is stereotyped. Second, the levels of injured and intact spinal segments are completely separated, allowing independent experimental manipulations of the injured and intact spinal segments in future experiments to answer questions regarding mechanisms underlying causalgia.
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This study evaluates the reliability and validity of the Toddler-Preschooler Postoperative Pain Scale (TPPPS), an observational scale developed to be a clinically useful measure of postoperative pain in children aged 1-5 years. The TPPPS consists of 7 items divided among 3 pain behavior categories: (1) Vocal pain expression; (2) Facial pain expression; and (3) Bodily pain expression. These items were derived from preliminary studies by the authors and from other observational studies of children's pain behavior. ⋯ The TPPPS was found to possess satisfactory internal reliability (Cronbach's alpha = 0.88). Inter-rater reliability was good, with kappas for the pain behavior items ranging from 0.53 to 0.78. Preliminary evidence of the scale's validity is provided by the sensitivity of the scale to analgesic regimen, the convergence between TPPPS scores and nurse and parent ratings of postoperative pain, and the associations found between TPPPS scores and perioperative vital signs.
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The involvement of NMDA receptors in rats with peripheral inflammation and hyperalgesia was evaluated by administration of the non-competitive NMDA receptor antagonist, MK-801. Inflammation and hyperalgesia was induced by intradermal injection of complete Freund's adjuvant (CFA) or carrageenan into the left hind paw. The latency of paw withdrawal from a thermal stimulus was used as a measure of hyperalgesia in awake rats. ⋯ MK-801 had no significant effect on receptive field size of dorsal horn neurons in rats without CFA-induced inflammation but blocked a transient expansion of the receptive fields induced by 1 Hz, C-fiber intensity electrical stimulation of the sciatic nerve. The background activity and noxious heat-evoked response of dorsal horn neurons in rats with CFA-induced inflammation were primarily inhibited and noxious pinch-evoked activity was both facilitated and inhibited by the administration of MK-801. These results support the hypothesis that NMDA receptors are involved in the dorsal horn neuronal plasticity and behavioral hyperalgesia that follows peripheral tissue inflammation.
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The course of pain associated with temporomandibular disorders (TMD) and other chronic pain conditions is typically episodic. Its expression may influence when a person seeks treatment, for example, when the level of pain flares up or exceeds its characteristic severity. Improvement in pain status subsequent to entering treatment may be due to: (1) specific effects of treatment; (2) non-specific effects of treatment ('placebo effects'); or (3) regression to the mean. ⋯ A control group of TMD subjects not seeking treatment showed no mean reduction in pain intensity but reported lower pain intensity at baseline than the group seeking care. When both groups of subjects were stratified on baseline VAS pain values, the reduction in pain increased as the baseline pain level increased, but no differences between comparable treated and untreated cases in the extent of improvement were observed. The before-after differences in both groups may be attributed to regression to the mean.(ABSTRACT TRUNCATED AT 250 WORDS)