View clinical trials related to Hyperalgesia.
Filter by:The goal of this prospective, randomized, controlled study is to investigate the effect of remimazolam on opioid-induced hyperalgesia (OIH) in patients undergoing single port-laparoscopically assisted urologic surgery. The main question[s] it aims to answer are: - [The mechanical hyperalgesia threshold] - [Area of hyperalgesia around the surgical incision 24 h after surgery (cm^2)] In three groups: Group RHR (Remimazolam- High-dose Remifentanil), Group DHR (Desflurane-low-dose Remifentanil) or Group DLR (Control).
The main aim of our study was to test the hypothesis that Erector spine plane block (ESP) with sedation will provide the similar employment of fentanyl and propofol during surgery as an infiltrative local anaesthesia with sedation. The primary endpoint was the quantity of fentanyl and propofol during surgery.
This exploratory study is to improve an established pain model by a new stimulation profile that allows preferential activation of C fibers that are of main clinical interest in chronic pain and also to generate a stable secondary hyperalgesia, which is of particular interest in the actual research of acute and chronic pain. It is to investigate if the specific activation of afferent sensory fibers and expected lower current intensities makes it more comfortable for the participant as motor neuron activation is much less pronounced at low current intensities. Therefore it compares the area under the curve (AUC) of hyperalgesia during electrical, intracutaneous 25 ms half-sine wave stimulation at a pain level of the numeric rating scale (NRS) of 6 out of 10 for 65 minutes compared to 500 µs rectangular pulses.
Nocebo effects are known to adversely affect the experience of various physical symptoms, such as pain and itch. Nocebo effects can be induced by associative learning mechanisms of classical conditioning. Furthermore, recent studies have shown that counterconditioning can successfully reduce nocebo effects, and to a larger extent than mere extinction, which suggests counterconditioning can be an innovative method for desensitization of symptoms. When using such procedures in clinical practice, deception of patients should be avoided as much as possible. The use of open-label procedures could provide a promising alternative. While previous studies have already shown that open-label placebos are effective, the effects of open-label counterconditioning and closed-label counterconditioning are not extensively investigated in comparison to other strategies, such as extinction, and not yet compared amongst each other. Before implementing such a procedure in clinical practice, it would be relevant to get an insight in the efficacy of both open- and closed-label counterconditioning in healthy participants as compared to extinction and to investigate whether open-label counterconditioning can be equally effective as closed-label counterconditioning. Furthermore, it would be relevant to study the induction and reduction of nocebo effects using a pain modality that mimics the type of pain that people suffering from several chronic pain conditions experience, such as pressure pain. The main aim of the current study is to investigate whether open- and closed-label counterconditioning are more effective in reducing nocebo effects than extinction. To this aim, it will be investigated whether open- and closed-label counterconditioning lead to stronger reductions in nocebo effects on pressure pain than (closed-label) extinction, and whether all three successfully reduce nocebo effects. Finally, it will be tested whether open- and closed label counterconditioning are comparable in effectivity.
To explore the effect of daytime variation on postoperative hyperalgesia induced by opioids. Patients receiving endoscopy surgery under general anesthesia during 08:00-12:00(morning group, n=30) and 14:00-18:00(afternoon group, n=30) using remifentanil for anesthesia maintenance were respectively included. Postoperative hyperalgesia at PACU and 24 hours after surgery were assessed through mechanical pain measurement. Comparative analysis of postoperative hyperalgesia levels, pain and analgesic requirements between morning group and afternoon group were performed.
This planned study is based on a randomized, placebo-controlled cross-over design. Palmityhlethanolamide (PEA) is an endogenous fatty acid amide from the group of N-Acetylethanolamides, which analgesic, anti-inflammatory and neuroprotective effects can be attributed to this. In clinical studies, PEA has mainly been used as an adjuvant in pain therapy. The previous data show clinical efficacy without conclusions that can be drawn about the underlying mechanisms - these have not yet been investigated in a human experiment. The planned study, which demonstrates the mode of action of PEA using an established pain model on healthy volunteers, will help to assign the efficacy to peripheral or central nervous systems. These mechanisms allow to establish mechanism-oriented therapy approaches. These findings are essential for a better understanding of the clinical efficacy and to evaluate the correct fields of application.
The development of remifentanil-induced hyperalgesia (RIH) is an unpleasant experience for surgical patients. An alternative management, gradual withdrawal of remifentanil was effective in prevention of RIH. The investigators designed a simple modality to assess if under withdrawal of remifentanil and further drip-infusion of remifentanil immediately after extubation affected postoperative pain score, the requirement of rescue analgesics, and adverse effects.
Pain is a nociceptive somatosensory process that can arise as a debilitating and chronic symptom in various diseases or following an injury. How pain is experienced can vary widely within and across individuals, and can be shaped by cognitive processes such as learning. Nocebo effects, negative changes in symptom severity attributed to learned outcome-expectations, demonstrate how learning processes can be detrimental for the experience of pain. Research to date has produced inconclusive findings regarding the electrophysiological correlates on nocebo effects. The few studies that have applied electroencephalography (EEG) in this field have pointed towards a potential involvement of alpha-band activity, but the direction of this involvement remains unclear. For example, an EEG study of conditioned nocebo hyperalgesia found a pre to post increase in resting state alpha band power that was correlated with pain catastrophizing scores and not with the magnitude of the nocebo effect. Later, other studies also found pre to post changes in alpha band power, however, these changes were correlated with the magnitude of nocebo effects and not pain catastrophizing. Given the discrepancy in findings, in this study the investigators plan to primarily investigate whether EEG components predict the magnitude of nocebo responses to thermal-pain stimuli. The investigators will also explore electrophysiological correlates during pain anticipation and whether nocebo responses would be significantly related to spectral and temporal EEG biomarkers. This study will utilize a validated model of instructional and associative learning methods (i.e., negative suggestions and classical conditioning, respectively) to experimentally induce nocebo effects on heat-evoked pain. Developing objective, brain-derived markers for nocebo responses, or the detection of individuals most susceptible to nocebo hyperalgesia, will aid in the comprehensive management of pain. This study is conducted at Leiden University.
Nocebo hyperalgesia is characterized by adverse pain outcomes, induced by patients' expectations. In the lab, nocebo effects are commonly studied via classical conditioning, a method that employs pairings of neutral cues/treatments with different pain intensities to install differential pain-related expectations. In such conditioning experiments, participants are typically taught that a (sham) treatment exaggerates their pain, by surreptitiously administering high intensity (e.g. pain) stimuli in combination with this treatment. Verbal suggestions are also often used to inform participants of the supposed adverse effects of such treatments. In nocebo studies, higher pain levels and suggestions that are of more threatening nature may induce fear, thereby adding a crucial element to the experimental manipulation. Since nocebo effects are hypothesized to arise in clinical settings due to a combination of several psychological and cognitive mechanisms, it is important to study the role that factors such as higher pain levels, conditioned pain-related fear, or more threatening verbal suggestions may play in the formation of nocebo hyperalgesia. To date, no studies have focused on the fear-inducing effect that different pain intensities or verbal threat suggestions may have and how this fear, in turn, may strengthen the acquisition of nocebo effects. This study aims to investigate whether higher pain intensity or higher pain-related fear induced via threatening suggestions facilitate the acquisition and hinder subsequent extinction of nocebo hyperalgesia. This study will be conducted at Leiden University.
Prospective, randomized, placebo-controlled, double-blinded, crossover study to investigate the effect of cannabidiol (CBD) on remifentanil-induced hyperalgesia in healthy volunteers in a well-established acute pain model. Participants are randomized according to the order of the two treatments (CBD + Remifentanil or Placebo + Remifentanil).