Pain
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Randomized Controlled Trial Comparative Study Clinical Trial
Communicative dimensions of pain catastrophizing: social cueing effects on pain behaviour and coping.
The study was designed to assess whether the social context of a pain experience impacted on the relation between catastrophizing and duration of pain behaviour. Based on a communal coping model, the prediction was that the presence of an observer during a pain procedure would differentially influence the display of pain behaviour in high and low catastrophizers. University undergraduates taking part in a cold pressor procedure were randomly assigned to one of two conditions: (1) participant alone (n=30), or (2) observer present (n=34). ⋯ When the observer was present, high catastrophizers also reported using fewer cognitive coping strategies than low catastrophizers. The pattern of findings suggests that in the presence of an observer, high pain catastrophizers show a propensity to engage in strategies that more effectively communicate their pain, and are less likely to engage in strategies that might minimize pain. Theoretical implications of the findings are discussed.
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Randomized Controlled Trial Multicenter Study Clinical Trial
Pain and analgesic response after third molar extraction and other postsurgical pain.
There is uncertainty over whether the patient group in which acute pain studies are conducted (pain model) has any influence on the estimate of analgesic efficacy. Data from four recently updated systematic reviews of aspirin 600/650 mg, paracetamol 600/650 mg, paracetamol 1000 mg and ibuprofen 400 mg were used to investigate the influence of pain model. Area under the pain relief versus time curve equivalent to at least 50% maximum pain relief over 6 h was used as the outcome measure. ⋯ The event rate with placebo was systematically statistically lower for dental than postsurgical pain for all four treatments. Event rates with analgesics, RB and NNT were infrequently different between the pain models. Systematic difference in the estimate of analgesic efficacy between dental and postsurgical pain models remains unproven, and, on balance, no major difference is likely.
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Randomized Controlled Trial Comparative Study Clinical Trial
Addition of ultralow dose naloxone to postoperative morphine PCA: unchanged analgesia and opioid requirement but decreased incidence of opioid side effects.
Ultralow doses of naloxone (0.001-0.1 microg/kg) produce analgesia in animal models. However, no clinical study has evaluated the combination of ultralow dose naloxone and morphine using patient-controlled analgesia (PCA). This randomized, double blind controlled study sought to determine if the combination of ultralow dose naloxone and morphine in PCA solutions affects opioid requirements, analgesia, and side effects. ⋯ The morphine+naloxone group had a lower incidence of nausea and pruritus than the morphine group (P=0.01 for both symptoms). However, the incidence of vomiting, time to tolerate fluids, sedation, and urinary retention were similar between groups (all P values >0.1). The combination of ultralow dose naloxone and morphine in PCA does not affect analgesia or opioid requirements, but it decreases the incidence of nausea and pruritus.
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Randomized Controlled Trial Comparative Study Clinical Trial
The association between anger expression and chronic pain intensity: evidence for partial mediation by endogenous opioid dysfunction.
Recent work suggests that an expressive anger management style (anger-out) is associated with elevated acute pain sensitivity due to endogenous opioid antinociceptive dysfunction. We tested the hypothesis that this opioid dysfunction mediates the previously reported positive association between anger-out and chronic pain intensity. To assess endogenous opioid antinociception in the laboratory, 71 subjects with chronic low back pain received opioid blockade (8 mg naloxone i.v.) or placebo in counterbalanced order in separate sessions. ⋯ Inclusion of blockade effects in the first step of the regression resulted in a decrease from 7 to 3% in chronic pain variance accounted for by anger-out. Opioid dysfunction did not mediate the positive association between anger-in and chronic pain. These results provide preliminary support for the hypothesis that the positive association between anger expression and chronic pain intensity is mediated by opioid antinociceptive system dysfunction.
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Randomized Controlled Trial Comparative Study Clinical Trial
The placebo needle, is it a valid and convincing placebo for use in acupuncture trials? A randomised, single-blind, cross-over pilot trial.
The issue of what constitutes an effective and realistic acupuncture placebo control has been a continuing problem for acupuncture research. In order to provide an effective placebo, the control procedure must be convincing, visible and should mimic, in all respects, apart from a physiological effect, the real active treatment. The 'Streitberger' needle might fulfil these criteria and this paper reports on a validation study. ⋯ No major differences in outcome between real and placebo needling could be found. The fact that nearly 40% of subjects did not find that the two interventions were similar, however, raises some concerns with regard to the wholesale adoption of this instrument as a standard acupuncture placebo. Further work on inter-tester reliability and standardisation of technique is highly recommended before we can be confident about using this needle in further studies.