View clinical trials related to Hyperalgesia.
Filter by:Modern anesthesia has made a lot of progress, however, postoperative pain remains one of the major problems associated with patient discomfort, prolonged hospital stay and increased health care costs. Remifentanil is an ultra-short-acting phenylpiperidine opioid analgesic with high lipid solubility and a rapid onset of effect. Recently, opioid use has also been associated with postoperative opioid-induced hyperalgesia or acute opioid tolerance. An immediate discontinuation of remifentanil has been associated to increased postoperative pain levels. We would like to investigate whether a gradual post-operative withdrawal of remifentanil is indeed associated with less immediate pain compared to after an abrupt withdrawal in surgical patients undergoing minor surgery.
To explore and compare antihyperalgesic effects of Dexmedetomidine,Nalmefene,and a combination of both received before anesthesia induction. To evaluate and examine the incidence of adverse effects with the purpose of selecting the optimum dose.
Remifentanil is a potent opioid widely used during the administration of general anesthesia. There is a lot of evidence that suggest that the used of remifentanil is associated with the development of hyperalgesia (a reduction of nociceptive thresholds). However, the mechanism of this hyperalgesia is not fully understood. Recently, it was demonstrated that the disruption of the Cl- homeostasis could be involved. Interestingly, this was prevented in a murine model with the administration of Acetazolamide, a carbonic anhydrase inhibitor. In our clinical trial we will try to determine if the preoperative administration of acetazolamide could prevent the hyperalgesia induced by remifentanil in patients scheduled for thyroidectomy with general anesthesia.
Recent studies have focused on the role of endogenous opioids on central sensitization. Central sensitization is known to be impaired or altered in chronic pain conditions, as fibromyalgia or chronic tension headache. Animal studies have shown reinstatement of mechanical hypersensitivity following naloxone administration after resolution of an injury. This suggests latent sensitization. In the present study, the investigators hypothesize that a high-dose target-controlled naloxone infusion (total dose: 3.25 mg/kg) can reinstate pain and hyperalgesia 6-8 weeks after a unilateral primary open groin hernia repair procedure. The investigators aim to show that latent sensitization is present in humans and is modulated by endogenous opioids.
In the last few years much attention has been paid to hyperalgesia induced by opioids, which represents a clinically significant condition following acute and chronic exposure to opioids. It has been suggested that the increase in gene expression of μ-opioid receptors and the development of hyperalgesia could be linked to epigenetic mechanisms. In particular the use of opioids seems to be related to an increase of the degree of DNA methylation. In the literature are not currently available data about the degree of DNA methylation in surgical patients, opioid-naive prior to surgery, receiving acute opioids treatment in the perioperative period. The primary objective of this study is to assess the degree of perioperative DNA methylation (extracted from whole blood) in patients undergoing major surgery exposed to opioids according to current clinical practice compared to preoperative baseline levels. The timing (preoperative vs intraoperative vs postoperative) in which the possible increase of the degree of DNA methylation will happen wil be assessed. 20 consecutive patients undergoing major surgery performed under general anesthesia that have expressed their consent to participate to the study will be enrolled. This sample is adequate to allow the observation of a possible increase of DNA methylation in opioid-naive patients exposed to anesthesia/analgesia based on opiates according to current clinical practice.
An fMRI study in healthy volunteers to investigate the effects of ABX-1431 on experimental hyperalgesia and its neural correlates.
High-dose remifentanil infused intraoperative ironically results in postoperative hyperalgesia. Ultra-low dose nalxone is demonstrated to prevent these opioid-induced hyperalgesia in animal model. In this clinical trial in patients undergoing general anesthesia with remifentanil, we evaluate the effects of ultra-low-dose naloxone on remifentanil-induced hyperalgesia
In several rodent studies, it has been demonstrated that very high doses of opioid antagonists (i.e., naloxone 3-10 mg/kg) administered after weeks after recovery from an inflammatory injury may lead to a reinstatement of hyperalgesia and pain behavior. This latent sensitization has recently been demonstrated also to take place in humans. The present study examines if it is possible to foresee individuals who will demonstrate a larger degree of latent sensitization upon challenge with an injury, than others. Using an enriched design high sensitizers (e.g., the upper quartile of individuals developing large areas of secondary hyperalgesia following a mild burn injury) are compared with low sensitizers (lower quartile), regarding the propensity for developing latent sensitization
The aim of this study is to quantitatively characterize the effects of L-menthol as a topical counter-irritant on cutaneous pain and hyperalgesia provoked by topical application of the TRPA1-agonist trans-cinnamaldehyde (CA) in healthy human volunteers.
The aim of this study is to assess the anti-hyperalgesic effect of dextromethorphan in healthy volunteers compared to placebo.