Topical nitroglycerin and lidocaine locally vasodilate the radial artery without affecting systemic blood pressure: A dose-finding phase I study
Journal of Critical Care, 06/15/2012Majure DT et al.
Topical nitroglycerin and lidocaine significantly increase radial artery diameter (RAD) within 30 to 60minutes with no effect on contralateral radial artery or blood pressure, indicating a direct, local effect on the radial artery.
This was a randomized, double–blind, placebo–controlled study.
In the first visit, to determine the optimal dose of nitroglycerin, subjects were randomized to either 15 or 30mg nitroglycerin on one wrist and placebo on the other.
In visit 2, to assess for any effect of lidocaine on the vasodilator function of nitroglycerin, the same subjects were randomized to 20mg lidocaine+30mg nitroglycerin vs 20mg lidocaine+placebo, or 40mg lidocaine+30mg nitroglycerin vs 40mg lidocaine+placebo.
In both visits, blood pressure and RAD using ultrasonography were measured for 2hours.
In visit 1, both nitroglycerin groups significantly increased RAD, with greater increases with 30mg nitroglycerin (P<.01) and no significant increase in RAD in placebo wrists.
In visit 2, increase in RAD was significantly greater with 20mg lidocaine+30mg nitroglycerin vs 20mg lidocaine+placebo (P<.001), and 40mg lidocaine+30mg nitroglycerin vs 40mg lidocaine+placebo (P<.001), indicating that lidocaine does not alter the effect of nitroglycerin.
There were significant increases in RAD seen as early as 30minutes.
There were no significant change in RAD in lidocaine+placebo–treated wrists and no change in blood pressure in any group.
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