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
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
Comparative study of electronic vs. paper VAS ratings: a randomized, crossover trial using healthy volunteers.
The visual analogue scale (VAS) is an established, validated, self-report measure usually consisting of a 10 cm line on paper with verbal anchors labeling the ends. Palmtop computers (PTCs also known as personal digital appliances) have incorporated VAS entry by use of a touch screen. However, the validity and psychophysical properties of the electronic VAS have never been formally compared with the conventional paper VAS. ⋯ The median of correlations comparing eVAS and pVAS ratings was 0.99 for verbal stimuli and 0.98 for sensory stimuli. Multivariate analyses showed equivalent stimuli to be rated much the same whether entered on paper VAS or PTC touch screen VAS (P < 0.0001). Support was found for the validity of the computer version of the VAS scale.
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A systematic review and subset meta-analysis of published randomised controlled trials of psychological therapies for children and adolescents with chronic pain is reported. A search of four computerised abstracting services recovered 123 papers from which 28 potential trials were identified. Eighteen met the criteria for inclusion in the review. ⋯ Meta-analysis was applicable for 12 headache trials and one trial of recurrent abdominal pain using the Pain Index. The odds-ratio for a 50% reduction in pain was 9.62 and the number needed to treat was 2.32, indicating that the psychological treatments examined are effective in reducing the pain of headache. The quality of the 18 trials retrieved is narratively reviewed and suggestions for the development of trials in this field are made.
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Randomized Controlled Trial Clinical Trial
Blinding effectiveness and association of pretreatment expectations with pain improvement in a double-blind randomized controlled trial.
Patient, provider, and clinical investigator expectations concerning treatments are believed to play important roles in patient response. This study examined the association of patient and research nurse/physician pretreatment expectations of pain relief with actual pain relief, the accuracy of patient and research nurse guesses about patient medication assignment, and changes in research nurse and patient pain relief expectations over the course of a randomized double-blind trial of amitriptyline versus an active placebo for patients with chronic pain and spinal cord injuries (SCI). Patient expectations of pain relief with amitriptyline were associated significantly with actual pain decrease for patients in the amitriptyline, but not placebo, condition. ⋯ The research nurse's, but not the patients', expectations of pain relief with amitriptyline decreased significantly over the course of the study. These findings have implications for future randomized controlled trials. Fully double-blind conditions are very difficult to achieve, and it is informative to assess patient and research clinician expectations and guesses regarding medication assignment.