Effects of Ketorolac on Vein Size and Nerve Activity During Venous Distension in Adults Aged 21 to 35

What this Trial Is About

This research aims to understand how the venous distension reflex VDR works in adults aged 21 to 35. The study explores whether blocking cyclooxygenase COX with ketorolac tromethamine, an intravenous nonsteroidal anti-inflammatory drug NSAID, reduces muscle sympathetic nerve activity during limb venous distension. It also investigates if COX blockade changes vein sizes measured by MRI during venous distension. Participants will undergo a wrist-to-elbow occlusion procedure with infusions of ketorolac tromethamine or saline on separate days, serving as their own control. The ketorolac infusion occurs in two steps a first infusion to block COX and a second to induce venous distension. In the saline control trial, the same volumes of saline are infused without ketorolac. MRI scans will be performed while lying supine to measure vein size before and during occlusion. During the 3-4 hour study visits, continuous recordings of muscle sympathetic nerve activity, vein size via MRI, heart rate, blood pressure, laser-Doppler flowmetry, strain gauge, and impedance will be collected. The trial includes randomized, triple-blinded crossover design, and participants will be monitored closely during procedures to assess the effects of COX blockade and venous distension.

Autonomic Control of the Circulation and VDR