Effect of High-dose Naloxone Infusion on Pain and Hyperalgesia in Patients Following Groin-Hernia Repair.
Central Nervous System Sensitization, Pain, Hyperalgesia
About this trial
This is an interventional basic science trial for Central Nervous System Sensitization focused on measuring central sensitization, endogenous opioids, humans, latent sensitization, naloxone, open groin hernia repair, pain, randomized controlled trial, secondary hyperalgesia, target-controlled infusion
Eligibility Criteria
Inclusion Criteria:
- Age ≥ 18 years and ≤ 65 years
- Signed informed consent
- Patients submitted to unilateral, primary inguinal, open herniotomy 6-8 weeks prior to study start.
- Open operating procedure a.m. Lichtenstein.
- Urin sample without traces of opioids (morphine, methadon, buprenorphine, codeine, tramadol, ketobemidone, oxycodone, hydromorphine, dextromethorphan)
- ASA I-II
- Body mass index (BMI): 18 < BMI < 30
Exclusion Criteria:
- Volunteers , who do not speak or understand Danish
- Patients, who cannot cooperate with the investigation
- Patients who have had previous surgery in the groin region
- Patients with pain at rest > 3 (NRS)
- Activity-related pain in the surgical field > 5
- Allergic reaction against morphine or other opioids (including naloxone),
- Abuse of alcohol or drugs - according to investigator's evaluation
- Use of psychotropic drugs (exception of SSRI)
- Neurologic or psychiatric disease
- Chronic pain condition
- Regular use of analgesic drugs
- Skin lesions and tattoos in the assessment areas
- Nerve lesions in the assessment sites (for instance, after trauma, disc herniation, etc.)
- Use of prescription drugs 1 week before the trial
- Use of over-the-counter drugs 48 hours before the trial
Sites / Locations
- Multidisciplinary Pain Center, 7612, HOC, RigshospitaletRecruiting
Arms of the Study
Arm 1
Arm 2
Placebo Comparator
Experimental
Placebo
Target-controlled naloxone-infusion (total dose: 3.25 mg/kg)
Change in Pain Ratings (NRS) at the surgical site and at the mirror-site in the contralateral groin six to eight weeks after unilateral herniotomy following administration of placebo.
Change in Pain Ratings (NRS) at the surgical site and at the mirror-site in the contralateral groin six to eight weeks after unilateral herniotomy following administration of naloxone.