Radial Artery Dilation Study: The Effect of Topical Administration of Nitroglycerin and Lidocaine Versus Lidocaine Alone of the Radial Artery Diameter

Study Overview
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Brief Summary
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The radial artery, which is located on the outer side of the forearm, can be used in interventional procedures, such as cardiac catheterization, to provide access to the arterial blood supply. In order to facilitate successful catheterization of the artery, a dilated artery and one free of arterial spasm is desirable. The proposed study will randomize twenty three healthy subjects in 2 visits to determine the effect of topical nitroglycerin on radial artery vasodilation. Radial artery diameter will be measured with ultrasound at regular intervals up to two hours.

Detailed Description
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During the first study visit, as a dose-optimizing study, each subject will be randomly assigned to one of two Dose-Test arms to receive either 15mg or 30mg of nitroglycerin on one wrist and placebo on the other. Radial artery diameter will be measured with ultrasound at regular intervals up to two hours. On the second study visit, the same participants will be randomly assigned to one of two Combination-Test arms to receive bilateral topical application of either 20mg or 40mg of lidocaine; the lidocaine will be applied in combination with 30mg of nitroglycerin on one wrist and in combination with placebo on the other wrist. Measurements of radial artery diameter will be performed as in the first visit.

Official Title
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The Effect of Topical Administration of Nitroglycerin and Lidocaine Versus Lidocaine Alone of the Radial Artery Diameter

Conditions
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Healthy

Intervention / Treatment
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* Drug: Nitroglycerin 15mg
* Drug: Nitroglycerin 30mg
* Drug: Lidocaine 20mg
* Drug: Lidocaine 40mg
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Willing and able to give written informed consent and comply with study requirements Patient who speak English Exclusion Criteria: Presence or history of liver, cardiovascular, rheumatologic, cancer or renal disease. Current treatment with any vasodilator therapy Systolic blood pressure of less than 90 mmHg History of radial artery catheterization within the previous year Absence of radial artery blood flow in one or both arms Pregnancy. Active infection Staff members of the Cardiac Catheterization Laboratory.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Dose Test 15mg NTG<br>Nitroglycerin 15mg (NTG) applied topically to one wrist and placebo to the other wrist at Visit 1 | Drug: Nitroglycerin 15mg<br>* 15mg Nitroglycerin applied topically to one wrist<br>Drug: Placebo<br>* Topical skin moisturizing cream with same appearance as active agent<br>* Other names: skin moisturizing cream;|
| Experimental: Dose Test 30mg NTG<br>Nitroglycerin 30mg applied topically to one wrist and placebo to the other wrist at Visit 1 | Drug: Nitroglycerin 30mg<br>* 30mg Nitroglycerin applied topically to one wrist<br>Drug: Placebo<br>* Topical skin moisturizing cream with same appearance as active agent<br>* Other names: skin moisturizing cream;|
| Experimental: Combination Test 20mg Lidocaine<br>Lidocaine 20mg + Nitroglycerin 30mg applied topically to one wrist, Lidocaine 20mg + placebo applied to the other wrist, at Visit 2 | Drug: Nitroglycerin 30mg<br>* 30mg Nitroglycerin applied topically to one wrist<br>Drug: Lidocaine 20mg<br>* 20mg Lidocaine applied topically to one wrist in combination with nitroglycerin or placebo<br>Drug: Placebo<br>* Topical skin moisturizing cream with same appearance as active agent<br>* Other names: skin moisturizing cream;|
| Experimental: Combination Test 40mg Lidocaine<br>Lidocaine 40mg + Nitroglycerin 30mg applied topically to one wrist, Lidocaine 40mg + placebo applied to the other wrist, at Visit 2 | Drug: Nitroglycerin 30mg<br>* 30mg Nitroglycerin applied topically to one wrist<br>Drug: Lidocaine 40mg<br>* 40mg Lidocaine applied topically to one wrist in combination with nitroglycerin or placebo<br>Drug: Placebo<br>* Topical skin moisturizing cream with same appearance as active agent<br>* Other names: skin moisturizing cream;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percent Change in Diameter of Radial Artery as a Dose Test for Nitroglycerin | Radial artery diameter was measured with ultrasonography using a high-frequency (13 MHz) linear array transducer 2 cm proximal to the radial styloid process. | Baseline, 10 minutes, 30 minutes, 60 minutes, and 120 minutes after topical application at Visit 1 | 
| Percent Change From Baseline in Radial Artery Diameter to Compare Combination of Nitroglycerin or Placebo and Lidocaine (20mg or 40mg) | Radial artery diameter was measured with ultrasonography using a high-frequency (13 MHz) linear array transducer 2 cm proximal to the radial styloid process. To compare combination of (Lidocaine + Nitroglycerin) or (Lidocaine + placebo), at visit 2, participants randomized to Comparison A received 30mg NTG + 20mg Lidocaine on one wrist, and placebo + 20mg Lidocaine on the other wrist; participants randomized to Comparison B received 30mg Nitroglycerin + 40mg Lidocaine on one wrist, and placebo + 40mg Lidocaine on the other wrist. | Baseline, 10 minutes, 30 minutes, 60 minutes, and 120 minutes after topical application at Visit 2 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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To determine if topical nitroglycerin acts to vasodilate the radial artery by a direct local action, or by systemic vasodilation, To determine if topical nitroglycerin dilates the radial artery in the presence of local anesthetic agents used in cardiac catheterization