Pain
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Randomized Controlled Trial Clinical Trial
Naloxone increases pain induced by topical capsaicin in healthy human volunteers.
Opioid receptors occur in locations of strategic importance within the central nervous system for modulation of pain. Is pain reduced by ongoing inhibition mediated by activation of these receptors? Experiments to date in which the opioid-receptor antagonist, naloxone, is administered during a painful event have yielded unclear results. Topically applied capsaicin can be used to induce tonic pain of moderate to severe intensity without tissue injury and is an ideal stimulus for studying acute pain modulation. ⋯ The naloxone induced a significant increase in pain compared both to baseline (P < 0.01) and placebo (P < 0.01). The peak effect, reached at 12-20 min after naloxone delivery, was 59% greater than placebo. This experiment suggests that acute pain is actively suppressed by endogenous opioid-receptor activation.
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Randomized Controlled Trial Clinical Trial
Magnesium Bier's block for treatment of chronic limb pain: a randomised, double-blind, cross-over study.
Magnesium is a physiological antagonist of both calcium and the NMDA receptor. Patients with chronic pain of a limb (>1 month's duration) were treated with two Bier's blocks (250 mmHg, 10 m) in a randomised, double-blind, cross-over design. They received once 20% magnesium sulphate (500 mg) + lignocaine 1% (75 mg), and once physiological saline + lignocaine 1% (75 mg). ⋯ For patients with chronic limb pain, the addition of magnesium to a Bier's block with lignocaine improves and prolongs pain relief and reduces the number of treatment failures. The optimal dose of lignocaine to prevent magnesium-induced aching of the treated limb needs to be established. Bier's block with magnesium-lignocaine may provide a possible treatment alternative in these patients.
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Randomized Controlled Trial Clinical Trial
Immediate effects of dry needling and acupuncture at distant points in chronic neck pain: results of a randomized, double-blind, sham-controlled crossover trial.
To evaluate immediate effects of two different modes of acupuncture on motion-related pain and cervical spine mobility in chronic neck pain patients compared to a sham procedure. Thirty-six patients with chronic neck pain and limited cervical spine mobility participated in a prospective, randomized, double-blind, sham-controlled crossover trial. Every patient was treated once with needle acupuncture at distant points, dry needling (DN) of local myofascial trigger points and sham laser acupuncture (Sham). ⋯ For patient assessment of change, non-local acupuncture was significantly superior both to Sham (1.7 points; 95% CI 1.0, 2.5; P = 0.0001) and DN (1.5 points; 95% CI 0.4, 2.6; P = 0.008) but there was no difference between DN and Sham (0.1 point; 95% CI -1.0, 1.2; P = 0.8). Acupuncture is superior to Sham in improving motion-related pain and ROM following a single session of treatment in chronic neck pain patients. Acupuncture at distant points improves ROM more than DN; DN was ineffective for motion-related pain.
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Randomized Controlled Trial Comparative Study Clinical Trial
Postsurgical pain outcome assessment.
Reliable and valid measures of pain are essential for conducting clinical trials of pain treatments. Perhaps the most important aspect of a pain measure's validity is its sensitivity, or ability to detect changes in pain over time and due to treatment. Several factors may affect a measure's sensitivity, including the complexity of the rating task for the measure, the number of pain intensity levels assessed by the measure, the dimension of pain assessed (e.g. pain intensity vs. pain relief), and the number of individual ratings (e.g. single rating vs. composite score) used to create the measure. ⋯ However, contrary to our prediction, a composite measure of outcome made up of all three measures was not consistently superior to the individual measures for detecting treatment effects. Finally, we found that pain relief ratings were related to, but also distinct from, change in pain intensity as measured by changes in pain intensity ratings from baseline to each postmedication assessment point. These findings have important implications for the assessment of pain in clinical trials.
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Randomized Controlled Trial Comparative Study Clinical Trial
Efficacy of continuous versus intermittent morphine administration after major surgery in 0-3-year-old infants; a double-blind randomized controlled trial.
A randomized double-blind clinical trial compared the efficacy of 10 microg/kg/h morphine continuous intravenous infusion (CM) with that of 30 microg/kg morphine (IM) every 3h after major abdominal or thoracic surgery, in 181 infants aged 0-3 years. Efficacy was assessed by the caregiving nurses with the COMFORT 'behavior' and a visual analogue scale (VAS) for pain, every 3h in the first 24h after surgery. Random regression modeling was used to simultaneously estimate the effect of randomized group assignment, actual morphine dose (protocol dosage plus extra morphine when required), age category, surgical stress, and the time-varying covariate mechanical ventilation on COMFORT 'behavior' and the observational VAS rated pain, respectively. ⋯ A significant interaction effect of condition with age category showed that the CM assignment was favorable for the oldest age category (1-3 years old). The greatest differences in pain response and actual morphine dose were between neonates and infants aged 1-6 months, with lower pain response in neonates who were on average satisfied with the protocol dosage of 10 microg/kg/h. Surgical stress and mechanical ventilation were not related to postoperative pain or morphine doses, leaving the inter-individual differences in pain response and morphine requirement largely unexplained.