The Effects of Different Type Vasodilator Agents on Radial Artery Blood Flow: A Placebo-Controlled Clinical Study

Background: The radial artery (RA) is being used as a second arterial conduit in coronary artery bypass grafting (CABG) patients. Vasospasm during the harvesting is the most common problem, yet. Our goal of this research is to evaluate the effects of different vasodilators on RA blood flow. Material and Method: In our 250 CABG patients who were included into the study, patients were divided into five groups which have the same number of the patients. Before the harvesting of the RA, Allen test and modified Allen test were performed. In group 1, sodium nitroprusside (SNP) was administered via central line. In group 2, nitrogliceryne was applied as a vasodilator agent. In group 3, diltiazem as a calcium channel blocker was used. In group 4, dobutamine was used with a dose of 3micro./kg/min. In the remaining patients, as a control group (CG), normal saline solution was used with the same protocol. RA length and radial artery flow, mean arterial blood pressure, central venous pressure, and heart rate were measured before and 10 minutes after drug administration. Results: No significant differences were found between the groups in respect to age, body surface area, cardiopulmonary bypass time, aortic cross clamp time. A multivariate general linear model was created and revealed the drug (specifically SNP and nitroglycerin) as a predictor to increase flow in the radial artery (p = 0.001 and p = 0.002), respectively. SNP has significantly decreased mean arterial pressure when we compared to nitroglycerin (p 0.05). Conclusions: Our study showed that SNP and nitroglycerin are very effective agents to provide the increasing of RA blood flow. However, statistical comparisons exhibited that intravenous SNP was a very effective vasodilating agent for RA than nitroglycerin.