Fig. 4

Serial changes of haemodynamic over time after the spinal anaesthesia of two groups. The red circles and their error bars represent the means and SDs of SBP and HR over times of 40 patients in RS group; The blue squares and their error bars represent the means and SDs of SBP and HR over times of 40 patients in R group. a Serial changes of SBP over time. b Serial changes of HR over time. *Significant difference between the two groups were assessed by multiple t test and determined by Two-stage linear step-up procedure of Benjamini, Krieger and Yekutieli, with Q = 1%. SBP, systolic blood pressure; HR, heart rate; bmp, beats per minute