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Remote Ischemic Preconditioning Mechanism Study

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ClinicalTrials.gov Identifier: NCT01541436
Recruitment Status : Completed
First Posted : March 1, 2012
Last Update Posted : October 24, 2017
Sponsor:
Information provided by (Responsible Party):

Study Description
Brief Summary:

This research is being done because pain is a significant problem for patients with a variety of medical problems and following surgery or traumatic injury. Currently available pain medications may not relieve all types of pain or may relieve pain only at doses that produce side effects and potential complications.

Although Remote Ischemic Preconditioning (RIPC) appears promising, there remain several unanswered questions about how it works. This research trial will help determine how RIPC may activate the bodies natural pain control system. The goals of this study are to see if RIPC has any effect 1) on a small area of skin that will be expose to a small amount of UV- B radiation (a mild sunburn), 2) on acute thermal heat temperatures that will be applied to skin, and 3) on the sunburn-like sensation to light touch after putting capsaicin cream (the active ingredient in hot chili peppers) on skin.

Remote ischemic preconditioning is done by inflating a balloon (very similar to a blood pressure cuff) on the leg until it blocks blood flow for a few minutes. The cuff is then deflated and blood flow resumes. The process is repeated up to three times. This procedure causes the body to increase its natural pain relief system that may help to decrease the amount of postsurgical pain.


Condition or disease Intervention/treatment Phase
Pain Device: Remote Ischemic Preconditioning, Capsaicin, UV-B Early Phase 1

Detailed Description:
The purpose of this pilot study is to determine whether RIPC effects peripheral sensitization, central sensitization or both and determine effect size since there is no data regarding the presumed effect. These issues cannot be easily sorted out in patients experiencing postoperative pain and hypersensitivity, since surgery affects both components. In order to address this purpose the investigators will examine, in healthy volunteers, the effect of RIPC on a manipulation which generates hypersensitivity by an exclusive peripheral mechanism (ultraviolet B (UV-B) burn) and a manipulation which generates hypersensitivity by an exclusive central mechanism (topical capsaicin). Understanding the sites at which RIPC reduces the amplification of pain after injury will be useful in determining where it would be most logically applied clinically and in guiding preclinical mechanistic studies.

Study Design

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 20 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
Official Title: Remote Ischemic Preconditioning Effects on Central and Peripheral Sensitization in Healthy Volunteers-A Pilot Study
Actual Study Start Date : March 2012
Primary Completion Date : March 2016
Study Completion Date : April 30, 2017

Resource links provided by the National Library of Medicine

Drug Information available for: Capsaicin
U.S. FDA Resources

Arms and Interventions

Arm Intervention/treatment
Active Comparator: Capsaicin, UV-B, RIPC Device: Remote Ischemic Preconditioning, Capsaicin, UV-B
The participants will have one disposable tourniquet applied to the left mid thigh by research personnel. The participants will then be randomized to the treatment group or sham group. The treatment group will receive 3 cycles of RIPC to the left lower leg by occluding blood flow at the thigh with a pneumatic cuff. Each cycle will consist of 5 minutes of ischemia by inflating the cuff to 300 mmHg followed by 5 minutes of reperfusion. The sham group will have the cuff inflated to no more than 15mmHg for three cycles as described above. Areas of hypersensitivity and allodynia will be obtained every 40 min for 280 min following the end of capsaicin application.
Sham Comparator: Capsaicin, UV-B Device: Remote Ischemic Preconditioning, Capsaicin, UV-B
The participants will have one disposable tourniquet applied to the left mid thigh by research personnel. The participants will then be randomized to the treatment group or sham group. The treatment group will receive 3 cycles of RIPC to the left lower leg by occluding blood flow at the thigh with a pneumatic cuff. Each cycle will consist of 5 minutes of ischemia by inflating the cuff to 300 mmHg followed by 5 minutes of reperfusion. The sham group will have the cuff inflated to no more than 15mmHg for three cycles as described above. Areas of hypersensitivity and allodynia will be obtained every 40 min for 280 min following the end of capsaicin application.


Outcome Measures

Primary Outcome Measures :
  1. Areas of hyperalgesia and allodynia to mechanical stimuli. [ Time Frame: 24 hours ]
    Hyperalgesia will be measured with vonFrey fibers and allodynia will be measured with a cotton wisp. The area will be measured in cm2.


Secondary Outcome Measures :
  1. Pain intensity and unpleasantness to mechanical stimuli [ Time Frame: 24 hours ]
    Using a Visual Analog Sliding Scale the intensity and unpleasantness will be measured in centimeters.

  2. Presence of parathesias where RIPC was used [ Time Frame: 24 hours ]
    After a brief tourniquet application I fully expect participants to have some degree of parasthesias. Using a standard rating scale I will record and report this.


Eligibility Criteria

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 55 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • healthy volunteers of both sexes ASA 1 or II classification
  • between the ages of 18-55
  • weighing less than 250 pounds
  • without chronic pain
  • not taking analgesics
  • off caffeine for 2 days.

Exclusion Criteria:

  • pregnancy
  • allergy to capsaicin
  • lower extremity vascular insufficiency
  • active treatment for DVT
  • severe thigh pain
  • taking psychotropic medications, including anti-depressants.
Contacts and Locations

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01541436


Locations
United States, North Carolina
WakeForestUBMC
Winston-Salem, North Carolina, United States, 27157
Sponsors and Collaborators
Wake Forest University Health Sciences
Investigators
Principal Investigator: Scott A Miller, MD Wake Forest University Health Sciences
More Information

Responsible Party: Wake Forest University Health Sciences
ClinicalTrials.gov Identifier: NCT01541436     History of Changes
Other Study ID Numbers: 00019284
First Posted: March 1, 2012    Key Record Dates
Last Update Posted: October 24, 2017
Last Verified: October 2017

Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: Yes
Device Product Not Approved or Cleared by U.S. FDA: No
Pediatric Postmarket Surveillance of a Device Product: No
Product Manufactured in and Exported from the U.S.: No

Keywords provided by Wake Forest University Health Sciences:
Remote Ischemic Preconditioning
Nociception
Central Sensitization
Peripheral Sensitization

Additional relevant MeSH terms:
Capsaicin
Antipruritics
Dermatologic Agents
Sensory System Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs