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Completed

NCT Number: NCT01541436

Remote Ischemic Preconditioning Mechanism Study

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.

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Key information

Conditions

Pain Neurologic Manifestations Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

18 year–55 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Early Phase 1

Primary location

WakeForestUBMC

Winston-Salem, North Carolina, 27157, United States

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

Remote Ischemic Preconditioning, Capsaicin, UV-B

Device

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.

Primary outcomes

  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 outcomes

  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.

Sponsors and collaborators

Lead sponsor

Wake Forest University Health Sciences

Other

Registry information

Official study title

Remote Ischemic Preconditioning Effects on Central and Peripheral Sensitization in Healthy Volunteers-A Pilot Study

Important dates

Study start
2012
Primary completion
2016
Study completion
2017
First posted
Mar 1, 2012
Registry last updated
Aug 10, 2018

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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