Comparison of the Effects of Ropivacaine and Bupivacaine on Human Umblical Artery Vasoreactivity

The primary aim of the current study was to examine the effect of ropivacaine and bupivacaine on human umblical artery reactivity and on clinical outcomes. Neither bupivacaine nor ropivacaine produce a significant effect on the maternal systolic blood pressure and heart rate during operation. However, ropivacaine and bupivacaine were used by addition of increasing concentrations of agonist (0.2-8 microg/ml) to the baths in a cumulative manner and the isometric tension devoloped by the tissue. In organ bath studies, bupivacaine caused a significant relaxation response in human umblical artery rings precontracted with either KCl or 5-hydroxytriptamine. Conversely, ropivacaine did not induce a relaxation response in umblical vessels which have been previously induced to contract by an activator. In conclusion, the results of this study have shown that bupivacaine, but not ropivacaine, may cause a significant effect on human umblical vessel tonus.