Active clinical trials for "Hyperalgesia"

The purpose of this study is to determine the effects of NGX426 on intradermal capsaicin induced pain in hyperalgesia.

Postoperative pain after major surgery is consecutive not only to the nociceptive inputs coming from the surgical lesion, but also to peripheral and central neuronal sensitization. This lead to postoperative hyperalgesia and allodynia that are enhanced by the per operative use of high opioid doses. Anti-NMDA drugs have been reported as able to reduce this sensitization process and then to decrease acute morphine tolerance during the postoperative period. Nefopam has been lately shown to combine in experimental trials analgesic and anti hyperalgesic effects. The aim of this study is to compare anti-hyperalgesic effects of nefopam given either before incision and continuously for the following 48hours or starting from the end of the surgery and given for 48hours to a control group that would receive placebo for 48hours. Postoperative analgesia will be based on morphine PCA. Pain scores, hyperalgesia, allodynia, postoperative morphine consumption, and development of chronic pain will be the main criteria that will be evaluated during this study

After surgery, sensitization and hyperexcitability of central nervous system result in acute and long lasting postoperative pain. It has been shown that N-methyl-D-aspartate (NMDA) receptors antagonist (such as ketamine) prevent this adverse neuroplasticity and potentiate analgesic drugs efficacy. Polyamines (putrescine, spermidine, spermine) are essential components of cells functioning and are also known as allosteric modulators of NMDA receptors. In animal studies, polyamine-free diet has confirmed these antinociceptive properties. This research aims at evaluating anti hyperalgesic properties of polyamine-free diet in women operated on breast cancer versus kétamine

To determine the effects of Lidocaine patch on the pain and hyperalgesia induced by intradermal capsaicin

The purpose of this study is to learn more about the role of genetics in pain sensitivity. Pain perception varies widely among individuals, and information gained from this trial may lead to better methods of preventing and controlling pain. The study consists of two parts, described below. All enrollees will participate in part 1; patients needing oral surgery for removal of third molars may also participate in part 2. Normal volunteers, oral surgery patients, and family members of both groups may be eligible for this study. Part 1 -Sensitivity testing for hot and cold. Participants will rate their pain response to hot and cold stimuli on a scale from "no pain" to the "worst pain imaginable." Heat sensitivity is measured using a small probe placed on the skin for a few seconds. The hottest temperature tested may cause pain for a few seconds but will not produce a burn. Response to cold is measured by placing the hand in cold water for up to 3 minutes and occasionally flexing the fist. Participants will rate their pain level every 15 seconds. In addition to the testing, a blood sample will be drawn to examine for genes related to pain. Part 2 - Oral surgery. Patients will have their third molar removed under a local anesthetic (lidocaine) injected in the mouth and a sedative (Versed) given through a vein in the arm. A small tissue biopsy will be taken from the tissue over one of the third molars. Patients will stay in the clinic for up to 7 hours after surgery while the anesthetic wears off and will rate any pain they may have according to the rating scale used in Part 1 of the study. Pain medication (ketorolac, or Toradol) will be given when needed, and patients will complete pain questionnaires for 3 hours after the drug is given to rate its effectiveness. Patients will receive additional pain relievers, if needed. A second biopsy on the side opposite the first will be taken under local anesthetic to measure changes in chemical signals produced in response to the surgery.

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.

The purpose of this study is to study if lidocaine, given intravenously, reduces pain.

Evaluation of the effects of 35%/15%/50% N2O/N2/O2 mixtures on the area of hyperalgesia induced by remifentanil in the CCES (Continuous Cutaneous Electrical Stimulation) model in 20 healthy volunteers. The duration of participation for each volunteer is expected to be around 9 weeks with the performance of 4 experimental session 2 weeks apart. The selection visit will last half a day; each experimental session will last half a day; the study end will last 2 hours maximum.

This research study explores whether a beta-blocker (propranolol) can prevent a person from becoming more sensitive to pain after administration of an opioid (remifentanil). Beta blockers inhibit the sympathetic (fight or flight) response and are often used to treat angina and high blood pressure. In a previous study in human volunteers, the investigators demonstrated an increased sensitivity to pain after a 60-minute infusion of the opioid remifentanil. The goal of this study is to identify a possible inhibitor of this phenomenon.

In this multicenter, randomised, placebo-controlled, double-blind trial, hyperalgesia area around the scarce following colorectal laparoscopic surgery (piece removal) will be assessed in 3 groups of patients : group 1: continuous ropivacaine preperitoneal infusion, group 2 : intravenous lidocaine infusion, or group 3 : control group without local anesthetics. All patients will receive parenteral analgesia combining acetaminophen and morphine.