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

University of California, San Francisco19 enrolled

Overview

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.

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

OTHER

Masking

SINGLE

Enrollment

Conditions

Healthy

Nitroglycerin 15mgDRUG

15mg Nitroglycerin applied topically to one wrist

Nitroglycerin 30mgDRUG

30mg Nitroglycerin applied topically to one wrist

Lidocaine 20mgDRUG

20mg Lidocaine applied topically to one wrist in combination with nitroglycerin or placebo

Lidocaine 40mgDRUG

40mg Lidocaine applied topically to one wrist in combination with nitroglycerin or placebo

PlaceboDRUG

Topical skin moisturizing cream with same appearance as active agent

Eligibility

Sex: ALLMin age: 18 YearsMax age: 35 YearsHealthy volunteers:

Medical Language ↔ Plain English

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.

Outcomes

Primary Outcomes

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.

Time frame: 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.

Time frame: Baseline, 10 minutes, 30 minutes, 60 minutes, and 120 minutes after topical application at Visit 2