Radial Artery Vasodilation Heat Study
Condition: Radial Artery
Study type: Interventional
Phase: Phase 1/Phase 2

Summary: 
      The purpose of this study is to collect data about the efficacy of utilizing distal topical
      heat application for dilatation of the radial artery. Transradial arterial access is widely
      accepted as the standard of care for cardiac catheterization procedures due to its increased
      patient comfort and significantly decreased risk of major vascular complications, and has
      been recently utilized in increasing volume by the interventional radiology community
      throughout the world. Due to the small size of the radial artery, catheterization may
      sometimes be technically difficult. Pre-procedure dilatation can make catheterization
      significantly easier, and studies have demonstrated the successful ability to dilate the
      radial artery with the use of topical nitroglycerin and lidocaine. However, the investigators
      hypothesize that utilizing topical heat applied distally can create a physiologic
      vasodilatation similar to that created with nitroglycerin and lidocaine, but at a
      significantly lower cost and with less risk due to no need for application of a medication
      which has a systemic effect with known side effects. The purpose of this study is to test the
      efficacy of radial artery vasodilatation with distal topical heat application.
    

Detailed description: 
      The study will be designed to detect a significant increase in the radial artery diameter of
      healthy volunteers after the application of a warm heat pack in the palmar aspect of the hand
      compared to a control group without heat applied to the hand. Employees and students at OHSU
      will be considered for enrollment as volunteers for this minimal risk study. Informed consent
      will be obtained from healthy volunteers prior to enrollment. After enrollment, the healthy
      volunteers will be randomly assigned in a 2:1 ratio to the heat group (Group 1) or the
      control group (Group 2), respectively. A brief medical history will be obtained from all
      volunteers, including age, sex, medications, prior interventions, prior surgeries, previous
      medical diagnoses, allergies, and any history of prior transradial procedures. For protection
      of confidential health information, brief medical history will be obtained in a private area.
      The volunteers will then be seated and the left hand placed supinated in a comfortable
      position on a table. A limited ultrasound of the left radial artery will be performed using
      grayscale ultrasound. A skin mark will be made with a marker to identify the measurement
      site. All volunteers will then be given a commercially available warm heat pack and asked to
      hold gently in their left hand. For the control group (Group 2), the warm heat pack will not
      be activated. For the heat group (Group 1), the warm heat back will be activated prior to
      placing in the volunteer's hand. Two investigators will be present. One investigator will be
      measuring radial artery diameter and will not be aware if the heat pack is activated. The
      second investigator will be aware of the volunteer's randomly assigned group and will
      activate the heat pack for the volunteer if they are assigned to Group 1. Over a period of 20
      minutes, repeat ultrasound of the left radial artery will be performed in 5 minute intervals.
    

Intervention name(s): Topical Heat
Intervention type(s): Procedure
Intervention description(s): Warm heat pack applied topically in participant hand.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Investigator)
Primary purpose: Treatment
Keywords: Transradial access; Radial artery; Vasodilation; Heat