Pain
-
Randomized Controlled Trial Clinical Trial
On the importance of placebo timing in rTMS studies for pain relief.
The efficacy of repetitive transcranial magnetic stimulation (rTMS) of the motor cortex for neuropathic pain relief is founded on double-blind studies versus placebo. In these studies, however, the analgesic effect of active interventions remained modest compared with the placebo effect. This observation led us to re-evaluate the intrinsic placebo action on pain relief according to the relative timing of active and sham rTMS interventions. ⋯ The fact that placebo effects could be enhanced by a previous rTMS with an analgesic effect as low as 10% suggests that a 30% pain decrease threshold in therapeutic trials may be too severe because smaller analgesic effects may have a clinical significance too. Sham rTMS induces significant analgesia only when preceded by a successful active stimulation. Such a placebo modulation is probably related to an unconscious conditioned learning.
-
Randomized Controlled Trial
Pregabalin in severe burn injury pain: a double-blind, randomised placebo-controlled trial.
This randomised, double-blind, placebo-controlled trial assessed the efficacy and tolerability of pregabalin to alleviate the neuropathic component of moderate to severe burn pain. Patients aged 18 to 65 years admitted to a burns unit with a 5% or greater total body surface area burn injury were screened to participate in the trial. Using the Neuropathic Pain Scale (NPS), patients scoring 4 or higher on 'hot' pain or 'sharp' pain were invited to participate. ⋯ There was no significant difference between the pregabalin and placebo treatment groups with respect to opioid consumption, duration of hospital stay, or pain at 6 months. Pregabalin was efficacious and well tolerated in patients after severe burn injury and whose pain was characterised by features of acute neuropathic pain. In this study, pregabalin was well tolerated and significantly reduced several elements of the neuropathic pain scale including hot pain, unpleasantness of the pain, surface pain, and itch, and also significantly reduced procedural pain.
-
Randomized Controlled Trial
Tropisetron blocks analgesic action of acetaminophen: a human pain model study.
Because the mechanism underlying the analgesic action of acetaminophen remains unclear, we investigated the possible interaction of acetaminophen with central serotonergic pathways. The effects of acetaminophen, tropisetron, the combination of both drugs, and saline on pain perception and central sensitization in healthy volunteers were compared. Sixteen healthy volunteers were included in this randomized, double-blind, placebo-controlled crossover study. ⋯ In summary, while the combination of acetaminophen and tropisetron showed no analgesic action, each drug administered alone led to decreased pain ratings as compared to saline. In an electrically evoked human pain model, the combination of acetaminophen with tropisetron was free of any analgesic potential. However, when administered on its own, both acetaminophen and tropisetron were mildly analgesic.
-
Randomized Controlled Trial
Effects of COX inhibition on experimental pain and hyperalgesia during and after remifentanil infusion in humans.
Opioids may enhance pain sensitivity resulting in opioid-induced hyperalgesia (OIH). Activation of spinal cyclooxygenase may play a role in the development of OIH. The aim of this study was to demonstrate remifentanil-induced postinfusion hyperalgesia in an electrical pain and a cold pain model, and to investigate whether COX-2 (parecoxib) or COX-1 (ketorolac) inhibition could prevent hyperalgesia after remifentanil infusion. ⋯ These results demonstrated OIH in both models, and may suggest that COX-2 inhibition is more important than COX-1 inhibition in reducing hyperalgesia. Remifentanil-induced hyperalgesia was demonstrated for both electrically induced pain and cold-pressor pain. Both parecoxib and ketorolac prevented hyperalgesia in the electrical model, parecoxib to a larger extent.
-
Randomized Controlled Trial
Long-term effects of routine morphine infusion in mechanically ventilated neonates on children's functioning: five-year follow-up of a randomized controlled trial.
Newborns on ventilatory support often receive morphine to induce analgesia. Animal experiments suggest that this may impair subsequent cognitive and behavioral development. There are sparse human data on long-term effects of neonatal morphine. ⋯ However, scores on one IQ subtest, "visual analysis," were significantly negatively related to having received morphine and to open-label morphine consumption the first 28 days. The finding of a significant effect of morphine on the "visual analysis" IQ subtest calls for follow-up at a later age focusing on the higher-order neurocognitive functions. Morphine received in the neonatal period has negative effects on the child's cognitive functioning at the age of 5 years which warrants follow-up at a later age.