postoperative secondary mechanical hyperalgesia and postoperative pain
Conditions
Interventions
Trade Name: Qutenza
Pharmaceutical Form: Cutaneous patch
INN or Proposed INN: Capsaicin
CAS Number: 404-86-4
Other descriptive name: CAPSAICIN
Concentration unit: mg milligram(s)
Concentration type: e
Sponsors
Wilhelminen hospital
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: • male or female, at least 18 years of age • planned elective surgery requiring incision of the abdominal wall • currently pain free or suffering from spontaneous pain in the last 24 hours of less than 4 on the numeric rating scale in the area of planned surgery • able to understand, read, and write German • willing and able to give informed consent Are the trial subjects under 18? no Number of subjects for this age range: F.1.2 Adults (18-64 years) yes F.1.2.1 Number of subjects for this age range 20 F.1.3 Elderly (>=65 years) yes F.1.3.1 Number of subjects for this age range 40
Exclusion criteria
Exclusion criteria: • patients undergoing scheduled surgery with less than 3 full days until surgery date • patients undergoing surgery with planned local anesthetic procedures (peripheral nerve block, , epidural or spinal anesthesia) or planned use of NMDA-receptor antagonists (i.e. ketamine i.v. or p.o.) • patients scheduled for postoperative controlled respiratory treatment at the intensive care unit (ICU) • patients under the age of 18 • patients suffering from acute or chronic pain with an intensity of greater than 3 on the numeric rating scale (spontaneous within the last 24 hours) • patients currently on prescribed regular analgesic medication • patients suffering from any known psychiatric condition • patients suffering from unstable hypertension • patients with implanted cardiac converter or pacemaker • pregnancy or breast-feeding • known abuse of alcoholic beverages or any illegal drug • known allergy against interventional or placebo medication, patch contents or study assessment devices • unable or unwilling to give informed consent • unable or unwilling to follow investigator’s instructions • unable or unwilling to comply with study protocol • patients suffering from any known medical conditions which may interact with study medication, study objectives, or compliance of subject with study tasks
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Primary end point(s): The primary outcome parameter is mean pain intensity to 7 defined pinprick stimuli applied in the area of secondary mechanical hyperalgesia surrounding the wound incision in capsaicin treated or vehicle treated (placebo) site on postoperative day one, i.e. 24 (±4) hours after surgery.;Timepoint(s) of evaluation of this end point: postoperative day one, i.e. 24 (±4) hours after surgery.;Main Objective: The goal of the present study is to prove that a two-day (48h) preoperative capsaicin skin treatment with capsaicin 8% patch leading to desensitization of capsaicin-sensitive (i.e. TRPV1-positive) fibers at the site of incision reduces postoperative mechanical secondary hyperalgesia on postoperative day (POD) one, in routine surgical patients.;Secondary Objective: Further goals of this study are to provide pilot data on the following hypotheses (i) TRPV1-fiber desensitization leads to a reduction of acute postoperative pain and/or analgesic consumption; (ii) the area of secondary hyperalgesia around the incisional site is reduced in patients pretreated with capsaicin; (iii) TRPV1-fiber desensitization leads to reduced primary hyperalgesia measured by electrical stimulation; (iv) postoperative pain amplification mechanisms (i.e. LTP-like pain plasticity via TRPV1-positive fibers) are a major factor in the development of persistent postsurgical pain; (v) TRPV1-expressing fibers are responsible for hyperalgesia in surgical patients as well thereby demonstrating translationability of preclinical results; (vi) a two-day capsaicin treatment immediately reduces C-fiber density at the site of patch application. | — |
Secondary
| Measure | Time frame |
|---|---|
| Secondary end point(s): • Mean pain ratings* (pain at the moment (at rest and upon movement), average pain since the day before, most intense pain since the day before) on postoperative day (POD) one, POD two, POD three. • Mean pain ratings and highest pain rating recorded during the first 90 minutes at the post-anesthesia care unit and pain rating upon discharge from the post-anesthesia care unit. • Daily consumption of opioids (i.e. analgesic consumption) administered via patient-controlled analgesia on POD 1, POD 2, and POD 3. • Mean pain to pinprick stimulus in the area of secondary mechanical hyperalgesia around incision site on POD three. • Mean pain ratings to electrical stimulation at the site of incision on POD 1 and POD 3 after the operation. • The mean area of secondary hyperalgesia around the site of incision on POD 1 and POD 3. • The mean pressure pain thresholds at the remote site (proximal tibia) on POD 1 and POD 3. • Conditioned pain modulation profile, measured by increase of pressure pain thresholds after cold pressor test versus baseline, and its impact on acute and persistent postoperative pain. • Incidence of persistent postoperative pain (NRS >0) at three months in both groups. *Pain ratings = pain rated on the numeric rating scale ranging from 0 to 100 (0 indicating no pain and 100 indicating most intense pain imaginable. ;Timepoint(s) of evaluation of this end point: postoperative day one, day two, and day three postoperative month 3 | — |
Countries
Austria
Contacts
Public ContactDepartment of Anesthesia
Wilhelminenspital
Outcome results
None listed