Figure 2. Linear regression analysis of the skin vasomotor reflex (SVmR) amplitude immediately before laryngoscopy with changes of systolic blood pressure (SBP) after intubation in study 1 showed a significant correlation (r²= 0.59, P < 0.001; lower panel). In contrast, the linear regression analysis of SVmR amplitude immediately before laryngoscopy with changes of heart rate (HR) after intubation showed no significant correlation (r²= 0.19, upper panel). Open circles and closed circles indicate the monitored group and the control group, respectively