Data processing and analysis
A power analysis showed that 16 parturients per group would provide an α value of 0.05 and a β value of 0.1, based on the total dose of vasopressors during cesarean section in a pilot study of 10 parturients. The Kruskal–Wallis test was used for comparison between groups, followed by Dunn’s post hoc test for pairwise comparisons. Data are presented as median and interquartile range. All statistical analyses were performed using GraphPad Prism® version 6.01 (GraphPad Software, Inc., La Jolla, CA), and 